CA3202479A1

CA3202479A1 - Device and method for renewable energy generation from ambient compressed fluid energy

Info

Publication number: CA3202479A1
Application number: CA3202479A
Authority: CA
Inventors: Raymond ASAMOAH-BARNIEH
Original assignee: Barnieh Inventions Inc
Current assignee: Barnieh Inventions Inc
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2022-06-23
Also published as: WO2022126225A1

Abstract

Devices and methods for generating renewable energy from a fluid by harnessing the ambient static pressure of the fluid are provided. The static pressure of fluid within the device is reduced below the ambient static pressure of fluid external to the device. A physical boundary of a thermodynamic system of the reduced static pressure fluid gets moved as a result of work being done on the thermodynamic system by the ambient fluid. In an embodiment, this work is done in response to the static pressure differential between the fluid in the device and the external fluid, namely the boundary moves from the higher static pressure side towards the lower static pressure side. Energy from this boundary movement may be harnessed as a means of renewable energy generation. The static pressure of the reduced static pressure fluid in the device is then restored, and the boundary is returned to its previous position. The cycle may then be repeated.

Description

DEVICE AND METHOD FOR RENEWABLE ENERGY GENERATION FROM AMBIENT
COMPRESSED FLUID ENERGY
FIELD
[0001] The present disclosure relates generally to energy generation from fluid energy, and more particularly to renewable energy generation from ambient compressed fluid energy by harnessing ambient fluid static pressure.
BACKGROUND

[0002] Energy is the basis for all civilization and humankind has tapped into different sources of energy over the different eras as it tries to meet an ever-growing demand for energy.
Manual labour was first explored as the energy source to power civilization but as the demand for energy grew, animal labour was explored as an energy source in activities such as agriculture and transportation to help meet the demand.

[0003] As the demand for energy grew, the age of the engines was born with the development of the heat engines and the related combustion engines. Various methods to operate the engines, called thermodynamic cycles and which include the Carnot Cycle and Rankine Cycle were developed as heat engine cycles. A common underlying operating principle for the heat engine technologies is that heat is taken from a high temperature source and rejected to a low temperature source and energy in the form of work is extracted in the process. The extraction of work was often as a result of the heat from the high temperature source being used to heat a working fluid to raise its pressure and the resulting high pressure working fluid impinging on a surface, a thermodynamic boundary between the high pressure working fluid and a low pressure ambient, to move the surface to do work.

[0004] A disadvantage of the heat engines is that one needs a high temperature source which is not always available and one needs to reject significant amounts of heat to a low temperature source which results in thermal pollution. The combustion engines, which are examples of heat engines, include external combustion engines such as coal fired and steam plants and internal combustion engines such as the petrol engine, Diesel engine and Wankel engine. Various thermodynamic cycles such as the Otto Cycle, the Diesel Cycle and the Brayton Cycle were developed in association with these. A common underlying operating principle of the combustion engine technologies is that they burn a fuel to generate the high temperature heat source needed to raise the pressure of a working fluid to power a heat engine cycle. A limitation of the combustion engines is that while they solved the problem of not readily having a high temperature heat source by burning a fuel such as coal or petroleum, these mostly fossil fuels were not renewable because they took geological time to form and were being burnt much faster than were being replenished, signalling a potential future energy shortage and an unsustainable

5 technological trajectory. A major disadvantage of the combustion engines is that they pollute the environment with their products of chemical combustion. These products of chemical combustion range from greenhouse gases such as carbon dioxide which warm the environment to adversely influence climate change to gases such as sulphur dioxide and nitrogen oxides responsible for acid rains, smog and fine particle pollution all of which are injurious to human health and the health of many species.
[0005] Mass energy has also been explored by humankind with the development of both the fission and fusion nuclear reactors. A common underlying operating principle of the mass energy technologies is that atomic mass is converted to thermal energy in accordance with Einstein's equation, and the thermal energy generated is then used to serve as a heat source to power a heat engine. The disadvantages of these are: the high capability of these energy sources for mass destruction due to the huge amounts of thermal energy released within very short periods, the challenges about adequate disposal of the radioactive nuclear waste released in the process as well as the genetic impact of any nuclear fallout released into the environment as a consequence of process imperfections.

[0006] Due to the limitations and disadvantages of the above energy technologies, there has been a global desire for humankind to harness clean renewable energy technology, for example as embedded in the United Nations Sustainable Development Goals of "Clean and Affordable Energy", "Climate Action" and "Sustainable Cities and Communities".
In harnessing renewable energy, aside the heat engine technologies which use renewable natural heat sources such as solar thermal energy or geothermal energy, there are two main sources namely:
photovoltaic energy and ambient fluid energy.

[0007] Regarding photovoltaic energy, various types of solar panels have been developed to convert sunlight into electrical energy. A common underlying operating principle of the photovoltaic technologies is that light absorbed by a material is used to create an electron-hole pair which if separated within the material, generates a voltage across the material to enable the electron to flow throw a connected external circuit to eventually recombine with the hole and with energy extracted from the flow of the electron in the connected external circuit by loads such as electrical, electronic, or electromechanical loads. The disadvantages of photovoltaic technology as an energy source include: its low power density which makes it difficult for it to meet global energy demand, its high capital cost and its competition with vegetation for solar energy used for photosynthesis, the basis of most food chains of all species, the basis of biological life.

[0008] Regarding ambient fluid energy, ambient fluids include but are not limited to the lakes, oceans, seas, rivers and atmosphere. There are two types of ambient fluid energy: (i) thermal ambient fluid energy which can be used to power heat engines, for instance heat engines which exploit a temperature difference between surface water and deeper waters (ii) mechanical ambient fluid energy.

[0009] Regarding mechanical ambient fluid energy, Bernoulli's Equation for energy conservation in fluids for a unit volume of fluid, P + 0.5pv2+ pgh = constant, (which can be re-written in extensive form after multiplying through by volume of fluid and substituting the product of density and volume of fluid with mass as PV+0.5mv2 +mgh = constant) suggests that there are at least 3 types of mechanical ambient fluid energy with each type being a component which contributes to the total available mechanical energy of any fluid. Each of these three components corresponds to a term in the Bernoulli Equation and they are: (i) ambient compressed fluid energy which is the energy the ambient fluid possesses by virtue of its static pressure, which is also called pressure energy or enthalpy and which corresponds to the first term of the Bernoulli Equation, P (ii) ambient fluid kinetic energy which is the energy the ambient fluid possesses by virtue of its dynamic pressure or kinetic pressure, which is also called kinetic energy and which corresponds to the second term of the Bernoulli Equation, 0.5pv2 (iii) ambient fluid gravitational potential energy which is the energy the ambient fluid possesses by virtue of its elevation in a gravitational field or elevation pressure, which also called gravitational potential energy or simply potential energy and corresponds to the third term of the Bernoulli Equation, pgh.

[0010] Humankind has been able to reliably generate commercial quantities of renewable energy from ambient fluid energy components corresponding to the second and third terms of the Bernoulli equation noted above, namely ambient fluid kinetic energy and ambient fluid gravitational potential energy, through various developments. However, humankind has not been able to reliably generate commercial quantities of renewable energy based on the first term, namely ambient compressed fluid energy, which is probably the most abundant source of renewable energy from ambient fluids and which is the subject of the present disclosure.

[0011] Regarding ambient kinetic fluid energy, which corresponds to the second term of the Bernoulli equation, the development of the turbines, for example the wind turbines, water turbines and Tesla turbine gave humankind the capability to unlock this energy source. In these technologies, the kinetic energy of an ambient fluid can be converted to renewable energy to drive a load. A common underlying operating principle of the kinetic fluid energy technologies is that the kinetic energy of a flowing fluid is tapped by having the flowing fluid to imping upon a surface to impart momentum to the surface to drive a load with the result being that the fluid is slowed down or stagnated as a consequence of loss of kinetic energy.

[0012] The limitations with harnessing the kinetic energy of ambient fluids for renewable energy generation is that it requires the fluid to be moving in bulk and moreover, the energy produced varies with the speed of the moving fluid. The requirement for a fluid to be moving in bulk cannot always be met, for example in still water bodies such as most lakes. Moreover, the dependence of the energy produced on the speed of the moving fluid also makes some of these technologies unreliable or at best, limited in use. This is because drag exists all around us slowing the motion of fluids so the norm is for fluids to move at relatively low speeds except in specific geographical areas or times where conditions favourable to high speed flows develop. In essence, the technology of harnessing the kinetic energy of ambient fluids though laudable, does not present a reliably feasible renewable energy solution to meet global energy demand to enable the entire world to quickly transition into a low carbon economy since it is plagued by both the geographical scarcity and temporal scarcity of ambient fluid kinetic energy.

[0013] Regarding ambient fluid gravitational potential energy, which corresponds to the third term of the Bernoulli equation, the development of the turbine and hydroelectric dam gave humankind the capability to unlock this energy source. In these, the gravitational potential energy of an ambient fluid can be converted to renewable energy to drive a load. A
common underlying operating principle is that the elevation of the ambient fluid is reduced thus converting its gravitational potential energy into kinetic energy which then drives a load just like the case of ambient kinetic fluid energy. In other words, the fast flowing fluid as a result of the elevation reduction is made to impinge upon a surface to impart momentum to the surface to drive a load with the result being that the fluid is slowed down or stagnated at the lower elevation as a consequence of loss of kinetic energy, than would have otherwise been the case had the kinetic energy not been extracted out. The reduction of the elevation of the ambient fluid can be achieved when the fluid flows over a waterfalls or a hydroelectric dam.

[0014] A disadvantage with harnessing the gravitational potential energy of ambient fluids for renewable energy generation is that it requires the incoming and outgoing fluid to be at different elevations while largely maintaining the same static pressure. This requirement cannot be met everywhere, for example in water bodies at a constant elevation such as most rivers and lakes or in ambient fluids such as atmospheric air where it is largely impossible to cause the incoming and outgoing fluids to be at different elevation without equivalently altering the static pressure to offset that. In essence, the technology of harnessing the gravitational potential energy of ambient fluids though laudable, does not present a reliably feasible renewable energy solution to meet global energy demand to enable the entire world to quickly transition into a low carbon economy since it is plagued by the geographical scarcity of elevation differences in suitable ambient fluid bodies.

[0015] Regarding ambient compressed fluid energy, which corresponds to the first term of the Bernoulli equation, humankind has largely not been able to unlock this energy source to generate renewable energy.

[0016] The above information is presented as background information only to assist with an understanding of the present disclosure. No assertion or admission is made as to whether any of the above, or anything else in the present disclosure, unless explicitly stated, might be applicable as prior art with regard to the present disclosure.

SUMMARY

[0017] According to an aspect, the present disclosure is directed to an apparatus comprising a moveable barrier at least partly defining a cavity, the cavity for receiving a fluid, wherein the barrier is configured for movement in response to a static pressure of fluid in the cavity being at a lower static pressure than an ambient static pressure of fluid on an opposing side of barrier relative to the cavity, and wherein the lower static pressure is a consequence of fluid motion, means for increasing the static pressure of the fluid in the cavity above the lower static pressure after movement of the barrier, means for further moving the barrier, after the increasing the static pressure of the fluid in the cavity, and means for maintaining the static pressure of the fluid in the cavity above the lower static pressure during the further moving the barrier, and means for decreasing, after the further moving the barrier, the static pressure of the fluid in the cavity below the ambient static pressure of fluid on an opposing side of barrier relative to the cavity.

[0018] In an embodiment, the apparatus further comprises an energy harnessing device linked to the moveable barrier for capturing energy from the movement of the barrier. In an embodiment, the means for increasing the static pressure of the fluid comprise a valve for selectively restricting the movement of fluid through or outwardly from the apparatus. In an embodiment, the means for decreasing the static pressure of the fluid comprise a valve for selectively increasing the movement of fluid through or outwardly from the apparatus.

[0019] In an embodiment, the apparatus comprises a deformable conduit, wherein the movable barrier is a deformable region of the deformable conduit, and wherein the movement of the barrier involves an inwardly movement of the deformable conduit. In an embodiment, the means for further moving the barrier is configured to at least partly restore the deformable conduit by reversing the inwardly movement. In an embodiment, the means for decreasing the static pressure of the fluid in the cavity are configured to enable a movement of the fluid through or outwardly from the deformable conduit. In an embodiment, the deformable conduit has a smaller cross-sectional area transverse to a fluid flow path through the deformable conduit relative to a cross-sectional area of a region of the fluid flow path in the apparatus upstream and/or downstream from the deformable conduit.

[0020] In an embodiment, the apparatus comprises a deformable correction conduit for receiving fluid from the deformable conduit, wherein the fluid is received in response to the inwardly movement of the deformable conduit, wherein the deformable correction conduit is adapted to move outwardly to increase a volume of the deformable correction conduit in response to the receiving of the fluid. In an embodiment, the deformable correction conduit is adapted to return toward a previous shape by moving inwardly as the deformable conduit is moved outwardly. In an embodiment, the outwardly movement of the deformable correction conduit to increase the volume of the deformable correction conduit in response to fluid received from the deformable conduit causes an internal volume of the apparatus to remain substantially unchanged with the inwardly movement of the deformable conduit.

[0021] In an embodiment, the deformable conduit comprises an elastic wall capable of deformation. In an embodiment, the deformable conduit comprises an opening that is selectively openable and closable to allow for fluid movement between the deformable conduit and an ambient side of the deformable conduit. In an embodiment, the apparatus comprises a pump for generating or enhancing fluid movement through and/or outwardly from the apparatus. In an embodiment, the apparatus may be configured such that the movement of the barrier, the increasing the static pressure of the fluid, the further moving the barrier, and the decreasing the static pressure of the fluid are repeated in a cycle.

[0022] In an embodiment, the apparatus is a rotary engine, the moveable barrier is a rotor of the rotary engine, and the movement is rotation of the rotor, and wherein the cavity is defined by the rotor and a rotor housing. In an embodiment, the means for increasing the static pressure of the fluid comprises the rotor, wherein the rotor is adapted to be rotated such that the cavity is moved out of fluid communication from a sub-ambient fluid intake vent and the cavity is moved into fluid communication with an ambient fluid intake vent. In an embodiment, the means for decreasing the static pressure of the fluid comprises the rotor, wherein the rotor is adapted to be rotated such that the cavity is moved into fluid communication with the sub-ambient fluid intake vent.

[0023] In an embodiment, the apparatus may be configured to receive as the fluid a working fluid that is separate from an ambient fluid to be located on an opposing side of barrier relative to the cavity.

[0024] According to an aspect, the present disclosure is directed to a method comprising exposing a cavity defined by a device to a fluid, the device comprising a moveable barrier at least partly defining the cavity, harnessing energy from movement of the barrier, wherein the movement is caused by a static pressure of fluid in the cavity being at a lower static pressure than an ambient static pressure of fluid on an opposing side of barrier relative to the cavity, and wherein the lower static pressure is a consequence of fluid motion, increasing, after the movement of the barrier, the static pressure of the fluid in the cavity above the lower static pressure, further moving the barrier, after the increasing the static pressure of the fluid in the cavity, and maintaining the static pressure of the fluid in the cavity above the lower static pressure during the further moving the barrier, and decreasing, after the further moving the barrier, the static pressure of the fluid in the cavity below the ambient static pressure of fluid on an opposing side of barrier relative to the cavity.

[0025] In an embodiment, the increasing the static pressure of the fluid involves selectively restricting the movement of fluid through or outwardly from the device. In an embodiment, the decreasing the static pressure of the fluid in the cavity involves selectively increasing the movement of fluid through or outwardly from the device. In an embodiment, the device comprises a deformable conduit at least partly defining the cavity, wherein the movable barrier is a deformable region of the deformable conduit, and wherein the movement of the barrier involves an inwardly movement of the deformable conduit. In an embodiment, the further moving the barrier involves at least partly restoring the deformable conduit by reversing the inwardly movement. In an embodiment, the decreasing the static pressure of the fluid in the cavity involves moving the fluid through or outwardly from the deformable conduit. In an embodiment, the deformable conduit has a smaller cross-sectional area transverse to a fluid flow path through the deformable conduit relative to a cross-sectional area of a region of the fluid flow path in the device upstream and/or downstream from the deformable conduit.

[0026] In an embodiment, the method further comprises receiving fluid from the deformable conduit into a deformable correction conduit in response to the inwardly movement of the deformable conduit, wherein the deformable correction conduit is adapted to move outwardly to increase a volume of the deformable correction conduit in response to the received fluid. In an embodiment, the deformable correction conduit is adapted to return toward a previous shape by moving inwardly as the deformable conduit is moved outwardly.

[0027] In an embodiment, the outwardly movement of the deformable correction conduit to increase the volume of the deformable correction conduit in response to fluid received from the deformable conduit causes an internal volume of the device to remain substantially unchanged with the inwardly movement of the deformable conduit. In an embodiment, the deformable conduit comprises an elastic wall capable of deformation. In an embodiment, the method further comprises selectively opening and closing an opening in the deformable conduit to allow for fluid movement between the deformable conduit and an ambient side of the deformable conduit. In an embodiment, the method further comprises using a pump to generate or enhance fluid movement through and/or outwardly from the device. In an embodiment, the operations of the method are repeated in a cycle.

[0028] In an embodiment, the harnessing energy from movement of the barrier comprises mechanically linking the barrier to an energy harnessing device. In an embodiment, the device is a rotary engine, the moveable barrier is a rotor of the rotary engine, and the movement is rotation of the rotor. In an embodiment, the increasing the static pressure of the fluid comprises rotating the rotor such that the cavity is moved out of fluid communication from a sub-ambient fluid intake vent and the cavity is moved into fluid communication with an ambient fluid intake vent. In an embodiment, the decreasing the static pressure of the fluid comprises rotating the rotor such that the cavity is moved into fluid communication with the sub-ambient fluid intake vent.

[0029] According to an aspect, the present disclosure is directed to a kit comprising a collection of parts that are assemble-able to form an apparatus, the apparatus comprising a moveable barrier configurable to at least partly define a cavity, the cavity for receiving a fluid, wherein the barrier is configurable for movement in response to a static pressure of fluid in the cavity being at a lower static pressure than an ambient static pressure of fluid on an opposing side of barrier relative to the cavity, and wherein the lower static pressure is a consequence of fluid motion, means configurable for increasing the static pressure of the fluid in the cavity above the lower static pressure after movement of the barrier, means configurable for further moving the barrier, after the increasing the static pressure of the fluid in the cavity, and means configurable for maintaining the static pressure of the fluid in the cavity above the lower static pressure during the further moving the barrier, and means configurable for decreasing, after the further moving the barrier, the static pressure of the fluid in the cavity below the ambient static pressure of fluid on an opposing side of barrier relative to the cavity.

[0030] In an embodiment, the kit further comprises an energy harnessing device linkable to the moveable barrier for capturing energy from the movement of the barrier.
In an embodiment, the means for increasing the static pressure of the fluid comprise a valve for selectively restricting the movement of fluid through or outwardly from the apparatus. In an embodiment, the means for decreasing the static pressure of the fluid comprise a valve for selectively increasing the movement of fluid through or outwardly from the apparatus. In an embodiment, the kit comprises a deformable conduit, wherein the movable barrier is a deformable region of the deformable conduit, and wherein the movement of the barrier involves an inwardly movement of the deformable conduit. In an embodiment, the means for further moving the barrier is configured to at least partly restore the deformable conduit by reversing the inwardly movement. In an embodiment, the means for decreasing the static pressure of the fluid in the cavity are configured to enable a movement of the fluid through or outwardly from the deformable conduit. In an embodiment, the deformable conduit has a smaller cross-sectional area transverse to a fluid flow path through the deformable conduit relative to a cross-sectional area of a region of the fluid flow path in the apparatus upstream and/or downstream from the deformable conduit.

[0031] In an embodiment, the kit further comprises a deformable correction conduit for receiving fluid from the deformable conduit, wherein the fluid is received in response to the inwardly movement of the deformable conduit, wherein the deformable correction conduit is adapted to move outwardly to increase a volume of the deformable correction conduit in response to the receiving of the fluid. In an embodiment, the deformable correction conduit is adapted to return toward a previous shape by moving inwardly as the deformable conduit is moved outwardly.

[0032] In an embodiment, the kit may be configured such that the outwardly movement of the deformable correction conduit to increase the volume of the deformable correction conduit in response to fluid received from the deformable conduit is configured to cause an internal volume of the apparatus to remain substantially unchanged with the inwardly movement of the deformable conduit. In an embodiment, the deformable conduit comprises an elastic wall capable of deformation.

[0033] In an embodiment, the deformable conduit comprises an opening that is selectively openable and closable to allow for fluid movement between the deformable conduit and an ambient side of the deformable conduit. In an embodiment, the kit further comprises a pump for generating or enhancing fluid movement through or outwardly from the apparatus. In an embodiment, the kit may be configured such that the movement of the barrier, the increasing the static pressure of the fluid, the further moving the barrier, and the decreasing the static pressure of the fluid are repeated in a cycle.

[0034] In an embodiment, the apparatus is a rotary engine, the moveable barrier is a rotor of the rotary engine, and the movement is rotation of the rotor, and wherein the cavity is defined by the rotor and a rotor housing. In an embodiment, the means for increasing the static pressure of the fluid comprises the rotor, wherein the rotor is adaptable to be rotated such that the cavity is moved out of fluid communication from a sub-ambient fluid intake vent and the cavity is moved into fluid communication with an ambient fluid intake vent. In an embodiment, the means for decreasing the static pressure of the fluid comprises the rotor, wherein the rotor is adaptable to be rotated such that the cavity is moved into fluid communication with the sub-ambient fluid intake vent.

[0035] In an embodiment, the apparatus may be configured to receive as the fluid a working fluid that is separate from an ambient fluid to be located on an opposing side of barrier relative to the cavity.

[0036] The foregoing summary provides some aspects and features according to the present disclosure but is not intended to be limiting. Other aspects and features of the present disclosure will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments in conjunction with the accompanying figures. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Embodiments of the present disclosure will now be described, by way of example only, with reference to the attached Figures.

[0038] Figure 1 is a pressure-volume graph according to an embodiment showing the difference between the system volume at any point and the initial system volume.

[0039] Figure 2 is a pressure-volume graph according to an embodiment showing the system volume.

[0040] Figure 3A is a diagram depicting an example thermodynamic system having a thermodynamic boundary with a moveable or deformable barrier in an original state.

[0041] Figure 3B is a diagram depicting the example thermodynamic system of Figure 3A wherein the moveable or deformable barrier is in a moved or deformed state.

[0042] Figure 4 is a diagram of an example embodiment of an ambient compressed fluid energy engine.

[0043] Figure 5 is a diagram of an example embodiment of an energy generation pipe of the engine of Figure 4.

[0044] Figure 6 is a diagram of the energy generation pipe of Figure 5 with the deformable conduit in a deformed state during a power stroke.

[0045] Figure 7 is an example process flow diagram according to the present disclosure.

[0046] Figure 8 is a diagram of an embodiment of a conduit.

[0047] Figures 9A and 9B are diagrams illustrating example embodiments of cavities or conduits having sliding wall(s).

[0048] Figure 10 is a diagram of a pipe wherein the main piston is mechanically coupled to piston rods, a crankshaft, and a flywheel.

[0049] Figure 11 is a diagram of an embodiment of a pipe having a diverging deformable conduit and a nozzle having a bellmouth shape.

[0050] Figure 12 is a diagram of an embodiment of a pipe having multiple inlet nozzles and an eductor.

[0051] Figure 13 is a diagram of an embodiment of a pipe where its inlet(s) to deformable conduit(s) are also the outlet(s) to the deformable conduit(s).

[0052] Figure 14 is a diagram of an embodiment of a pipe that does not utilize a pump for fluid flow through the pipe.

[0053] Figure 15 is a diagram of an embodiment of a rotary engine showing some externally connected features.

[0054] Figure 16 is cross-sectional view taken along line 16-16 in Figure 15 showing some internal features.

[0055] Figure 17 is a diagram of another example embodiment of an ambient compressed fluid energy engine wherein the fluid used in the engine is a working fluid.

[0056] Figure 18 is a block diagram of an example computerized device or system that may be used in implementing one or more aspects or components of an embodiment according to the present disclosure.

[0057] Figure 19 is a diagram of another energy generation pipe with the deformable conduit in a deformed state during a power stroke.

[0058] The relative sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and/or positioned to improve the readability of the drawings. Further, the particular shapes of the elements as drawn are not necessarily intended to convey any information regarding the actual shape of the particular elements, and have been solely selected for ease of recognition in the drawings.
DETAILED DESCRIPTION

[0059] This disclosure generally relates to energy generation from ambient compressed fluid energy by harnessing ambient fluid static pressure, for example atmospheric pressure and the hydrostatic pressure of lakes, oceans and rivers. Energy generated in this fashion may be used in any number of suitable ways, including to power engines and motors, to name but a few.
This type of energy harnessing may be contrasted to harnessing energy from the movement of fluid, meaning the kinetic energy of the fluid. An example of this is a hydroelectric turbine, which harnesses kinetic energy of a flowing body of water.

[0060] A fluid is generally referred herein to as an "ambient fluid" if the source of the fluid is the surrounding medium. Further, ambient fluid in the surrounding medium is generally referred to as being at an ambient static pressure.

[0061] Every fluid body around us, whether still or moving has compressed fluid energy by virtue of its static pressure and volume. This is a consequence of the fluid being within the gravitational field of the Earth in which it experiences the impact of gravitational compression.
Generally, the static pressure of the atmosphere around most human settlements largely fluctuates around 1 atmosphere. At the low end, one of the most elevated permanent human settlements known to have the lowest atmospheric pressures, La Rinconada in Peru, is said to be at a local atmospheric pressure within about 50% of the standard sea level atmospheric pressure. At the higher ends, in lakes and rivers with depths in excess of 80 meters, ambient fluid static pressures in excess of 8 atmospheres are common whereas at the bottom of the ocean in the Abyssal Plain where depths average in excess of 3000 meters, static pressures in excess of 300 atmospheres are common.

[0062] For an energy density comparison to get a sense of how much energy that corresponds to, category 5 hurricanes may have a dynamic pressure of just over 6% of 1 atmosphere implying that there is a potential to extract 16 times more energy per surface area from ambient compressed fluid energy on a normal day than from a wind turbine placed in a category 5 hurricane. In essence, ambient compressed fluid energy is reliably all around us with a high energy density and it is not plagued by the problems of temporal scarcity and geographical scarcity, at least at the low end of the ambient fluid static pressure spectrum. Ambient compressed fluid energy is instantly renewable by the effect of the gravitational pull of the Earth on all ambient fluid bodies, which forces the fluids to compress and causes these ambient fluids to act as thermodynamic pressure reservoirs. This represents an abundant safe reliable source of renewable energy, which may be tapped to help transition the world into a low carbon economy and to help meet the global demand for energy.

[0063] The present disclosure generally relates to methods and devices for effectively unlocking ambient compressed fluid energy as a source of renewable energy.
Specifically, the present disclosure generally relates to thermodynamic cycles and renewable energy engines for harnessing ambient fluid static pressure for producing power.

[0064] To reduce environmental pollution and sustainably meet rising global energy demand with very reliable renewable energy, it may be desirable to pioneer technologies to harness ambient compressed fluid energy for power production. These technologies are sometimes referred to herein as ambient compressed fluid energy technology.
While other energy generating technologies increase carbon footprint, chemical pollution, thermal pollution, hazards from radioactive fallout, and/or competition for light needed for photosynthesis, such ambient compressed fluid energy technology may not, which is beneficial especially in an era of increased climate change awareness and environmental sensitivity.

[0065] According to an aspect of the present disclosure, an ambient compressed fluid energy technology may be based on thermodynamic cycles that comprise the following stages:
boundary movement, static pressure increase, restoration, and static pressure reduction.

[0066] Aspects and advantages according to the present disclosure will be apparent from the following taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments according to the present disclosure.

[0067] For descriptive purposes, several aspects, embodiments, and features according to the present disclosure are described in relation to reciprocating engines.
However, this is not intended to be limiting. The teachings according to the present disclosure may be applied to fields and technologies other than reciprocating engines. Examples of other applications are rotary engines and energy harvesting devices.

[0068] Any sub-headings and indexes in this section shall not affect the construction of the disclosure, are not meant to be limiting and are only meant to enhance readability.

[0069] Figure 1 and Figure 2 are diagrammatic representations in the form of graphs of an example embodiment according to the present disclosure. The embodiment comprises a thermodynamic system having a boundary that defines the thermodynamic system.
There is fluid within the boundary and thus in the thermodynamic system. There is also fluid outside of the boundary of the thermodynamic system, for example in a surrounding medium, which is sometimes referred to herein as ambient fluid.

[0070] Figures 1 and 2 are pressure-volume diagrams, thermodynamically often referred to as PV diagrams, diagrams which show the variation of pressure with volume and familiar to those skilled in the art. A difference between the Figures 1 and 2 lies in the independent axis, the X-axis. While Figure 1 illustrates the difference between the system volume at any point in the cycle and the initial system volume, Figure 2 illustrates just the system volume at any point in the cycle.

[0071] Figures 1 and 2 highlight four system states 1, 2, 3 and 4, for harnessing energy from an ambient compressed fluid. These may be considered to correspond to 4 stages or thermodynamic processes: stage 1-2, stage 2-3, stage 3-4, stage 4-1 (thermodynamically, process 1-2, process 2-3, process 3-4 and process 4-1 respectively). For instance, stage 1-2 represents the stage when the system transitions from state 1 to state 2, and so on. These four stages may be repeated one or more times in a cycle. These stages are now described.

[0072] Stage 1-2 is referred to as a boundary movement stage, or sometimes a power stroke. In this stage, a boundary of a thermodynamic system moves as a result of work being done on the thermodynamic system by ambient fluid. This work is done in response to a reduction in the static pressure at an interior side of the boundary of the thermodynamic system relative to the static pressure at an ambient side of the boundary of the thermodynamic system. The absolute static pressure of the thermodynamic system is relatively lower than the ambient absolute static pressure. In other words, its interior static pressure is sub-ambient. This may be considered to be akin to negative gauge pressure in an extended sense as highlighted in both Figure 1 and Figure 2. The boundary of the thermodynamic system moves as a result of this static pressure differential. It is the energy of this movement that may be harnessed.

[0073] The above is illustrated in the example diagrams of Figures 3A and 3B, which depict a thermodynamic system 300. Figure 3A shows an example where the static pressure W
of fluid 304 at an interior side 306 of the thermodynamic boundary 302 is approximately the same as the static pressure W of fluid 310 at an exterior side 308 of thermodynamic boundary 302. At least part of thermodynamic boundary 302 comprises a moveable or deformable barrier 303. In an embodiment, moveable or deformable barrier 303 may define at least part of thermodynamic boundary 302. Exterior side 308 may be referred to as an ambient side since it is at an ambient static pressure. Similarly, fluid 310 is referred to as ambient fluid. In Figure 3A, moveable barrier 303 is in an original or starting state.

[0074] Figure 3B shows an example where the static pressure Z
of fluid 304 at the interior side 306 of the thermodynamic boundary 302 is lower than the static pressure W
of fluid 310 at the ambient side 308 of thermodynamic boundary 302. As a result of this static pressure differential, the moveable or deformable barrier portion 303 of boundary 302 moves inwardly towards the lower pressure of the two sides, namely towards interior side 306.
In this sense, boundary 302 is in a moved or deformed state. In this sense, boundary 302 may be considered to be pushed inwardly toward the lower pressure side by the static pressure W
of fluid 310 at the ambient side 308 of the thermodynamic boundary. Fluid 310 at the ambient static pressure does work through adiabatic expansion of its boundary 302 of thermodynamic system 300.

[0075] Turning back now to Figure 2, in an embodiment of stage 1-2, as highlighted in Figure 2, the movement of the boundary of the thermodynamic system may result in the final volume of the thermodynamic system being less than the initial volume. This volume decrease is shown in Figure 1. This causes the thermodynamic system to move from state 1 to state 2. An example way to accomplish this is to have a moveable thermodynamic boundary around a moving fluid whose static pressure at any point along the flow is less than the ambient static pressure. In an embodiment, the moveable boundary may consist or comprise a deformable boundary. The static pressure of the fluid may be made less than the ambient static pressure by, for example, imposing a pressure gradient which facilitates the conversion of the static pressure of the fluid into kinetic pressure, the venturi effect, leading to a decrease in the static pressure of the fluid in accordance with the Bernoulli Equation. Another example way to accomplish this is to have a moveable thermodynamic boundary around a fluid whose static pressure is less than the ambient static pressure as a result of previous fluid motion which facilitated the conversion of the static pressure of the fluid into kinetic pressure to reduce the static pressure of the fluid. In this example, the fluid whose static pressure is now less than the ambient static pressure need not be moving at the time of the movement of the boundary of the thermodynamic system.

[0076] As noted above, this boundary movement stage according to the present disclosure, characterized by sub-ambient static pressure, is a power generating stage. This stage and effect is in stark contrast to the power generating stage of an internal combustion engine which is often characterized by supra-ambient static pressure and volumetric expansion. In the present boundary movement stage, work is done by ambient static pressure against the static pressure in the thermodynamic system or engine. In contrast, in the power stage of the internal combustion engine, work is done by the static pressure in the thermodynamic system or engine against ambient static pressure. Thus, the techniques according to the present disclosure employ ambient static pressure beneficially as opposed to ambient static pressure being an obstacle.

[0077] We now turn to stage 2-3, which is referred to as a static pressure increase stage.
In this stage, the static pressure at the interior side of the boundary of the thermodynamic system is increased. This causes the thermodynamic system to move from state 2 to state 3. Ways to accomplish this may include but are not limited to collapsing the pressure field, which existed across the thermodynamic boundary in stage 1-2. Collapsing the pressure field may be done, for instance, by restricting fluid flow within the thermodynamic system to cause fluid dynamic pressure to be re-converted to fluid static pressure in accordance with Bernoulli's equation.
Restricting the flow may involve a partial reduction or a complete cessation of flow of the fluid.
Another way to accomplish this comprises changing the direction of the pressure field, for instance through stagnation pressure effects or sudden flow cessation within the thermodynamic system. This would cause transient flow phenomena such as transient pressure waves, known as water hammer for cases where the fluid is water, which may raise fluid static pressure considerably even if over a limited period of time. Another way to accomplish this may be opening a fluid at sub-ambient static pressure to fluid at ambient static pressure to enable inflow of ambient fluid to raise the pressure. Other ways may also be possible.

[0078] We now turn to stage 3-4, which is referred to as the restoration stage. In this stage, the boundary of the thermodynamic system is further moved while the static pressure at the interior side of the boundary of the thermodynamic system remains increased. For instance, the boundary may be moved to a previous location, for example to its position in stage 1-2 prior to its movement. This causes the thermodynamic system to move from state 3 to state 4. Ways to accomplish this may include but are not limited to moving the boundary of the thermodynamic system using its inertia, the inertia of loads attached to it or alternatively using power generated from stage 1-2 of another thermodynamic system while selectively restricting fluid flow within the thermodynamic system.

[0079] We now turn to stage 4-1, which is referred to as the static pressure reduction stage. In this stage, the static pressure at the interior side of the boundary of the thermodynamic system is reduced to a value lower than the static pressure at the ambient side of the boundary of the thermodynamic system. This causes the thermodynamic system to move from state 4 to state 1. Ways to accomplish this may include but are not limited to converting fluid static pressure into fluid dynamic pressure at constant elevation within the thermodynamic system. This in turn may be accomplished by causing inviscid flow at constant elevation to occur within the thermodynamic system or causing viscous flow at constant elevation within a thermodynamic system to occur while ensuring that the total pressure at any point in the flow is kept equal to or less than the ambient total pressure and that fluid flow speed within the thermodynamic system is maintained higher than fluid flow speed at ambient.

[0080] The difference between the pressure fields in the thermodynamic system and across its boundaries in stage 1-2 and stage 3-4 means that the system is not a perpetual motion machine of the first kind. In other words, across the moving boundary, the static pressure differential in stage 1-2 has a different value as compared to that of stage 3-4 so the forces present in boundary movement stage 1-2 are of a different magnitude than those present in restoration stage 3-4.

[0081] Figure 4 is a diagram of an example embodiment of an ambient compressed fluid energy engine 100 according to the present disclosure. Engine 100 is based on some of the techniques described above. In an embodiment, engine 100 operates fundamentally with four stages. In an embodiment, these four stages may operate within a 2 stroke cycle, such as for example a 2 stroke 4 stage reciprocating engine cycle.

[0082] Engine 100 is shown as having two pipes 102 and 104, each of which may be thought of as being analogous to cylinder-piston pairs in an internal combustion engine. Each of pipes 102, 104 generates power, and they both cooperate to power engine 100.
In other embodiments, an engine may have fewer or additional pipes. Although the structure and operation of pipe 102 is described herein, any other pipes in the engine, such as pipe 104, may generally have the same structure and operation. Pipes may have any shape and orientation including but not limited to straight, divergent, convergent, bent, multiple bends, level, rising, falling, rectangular, crescent, spiral, curved or any combinations of these and/or with other variations. All suitable variations in shape and orientation are contemplated.

[0083] Each of pipes 102, 104 embodies or defines a fluid flow path from an inlet region 105 of the pipe to outlet region 119 of the pipe. Fluid flow path is indicated by the arrow labeled 'F' in Figure 4. The fluid flow may comprise any number of phases including but not limited to single-phase flow or multi-phase flows as such 2 phase and 3 phase flows. All suitable variations in phase composition and behaviour of flow are contemplated. A deformable conduit 108 is disposed in the fluid flow path between inlet region 105 and outlet region 119, and is used to harness energy from a static pressure of the fluid. In this sense, deformable conduit 108 defines a cavity for receiving fluid. A group of pipes, such as pipes 102, 104 collectively define multiple flow paths within engine 100. Pipes 102, 104 may be adapted to operate alternately such that when one pipe is in a boundary movement stage (stage 1-2), the other pipe is in a restoration stage (stage 3-4). In this manner, power may be generated continuously.

[0084] Inlet region 105 of pipe 102 may include or be in the form of a nozzle 106, as shown in Figure 4, wherein a first region 106a has a larger cross-sectional area relative to a second region 106b closer to deformable conduit 108. References to cross-sectional areas herein generally refer to areas taken more or less perpendicularly to the fluid flow path.
Similarly, a diffuser 110 may be disposed downstream in the fluid flow path from deformable conduit 108, wherein a first region 110a closer to deformable conduit 108 has a smaller cross-sectional area, taken perpendicularly to the fluid flow path, relative to a second region (outlet area) 110b. Further, pipe 102 may comprise a valve 114, for example downstream from diffuser 110, for restricting fluid flow in the pipe. The term restricting is used herein to include both reducing fluid flow and completing stopping fluid flow, unless otherwise indicated. Valve may be a slide valve;
nanoparticles, ionic or molecular entities which self-assemble to restrict flow in response to a field such as an electric, magnetic or electromagnetic field or in response to radiation such as electromagnetic radiation; or any other type of suitable valve. The restricting and/or unrestricting of the flow may be selectively controlled. For instance, a valve may be selectively controlled to control the opening and/or closing of the valve. As an example, an actuator mechanism may be used to open and/or close the valve. The opening and/or closing may be done, for example, when the deformable conduit 108 changes its volume by a predetermined amount, for instance 2% as a mere example. In other words, the restricting and/or unrestricting of the flow may be done selectively and actively, as opposed to the restricting and/or unrestricting occurring in response to changes in static pressure in the device. Pipe 102 may comprise more than one selectively operated valve. Selectively operated valve(s) may be disposed in different locations in the flow to perform restricting and/or unrestricting of the flow at different locations including but not limited to generating specifically desired static pressure distributions in the device. Selectively operated valves may be operated in any desirable sequence and timings within the stages. All suitable variations in number of valves, location of valves, sequence of valve operation and timings of valve operation are contemplated.

[0085] Further, engine 100 may comprise one or more pumps 118 for inducing, generating, or enhancing fluid flow in engine 100 or pipe 102. Pump 118 may be, for instance, disposed downstream in the fluid flow path from valve 114. Further, there may be a pump inlet region 116 upstream from pump 118. Pump 118 may be used to pump fluid out of one or more of pipes 102, 104 at a sufficient rate such that the a static pressure of fluid in a pipe does not exceed a total pressure of fluid just prior to the fluid entering nozzle 106 of pipe. Also, the configuration of having pipes 102, 104 operate alternately, as described above, may ensure that at any point in time, there is at least one pipe 102, 104 in which flow is enabled to pump 118 to prevent pump 118 from stalling. Fluid that has exited pump 118 may be recirculated back to nozzle 106 of pipe 102. Further, fluid is present at at least one side of deformable conduit 108, for example at region 109. Fluid in this exterior region of pipe 102 may be generally referenced to as ambient fluid.

[0086] Pump 118 may be any type of suitable pump. Examples include but are not limited to centrifugal, diaphragm, peristatic, gear, piston, and lobe pumps. Further, pump 118 may be positioned at any suitable location in engine 100. Thus, in other embodiments, the pump may be disposed in a different location in engine relative to the embodiments of Figures 4 to 6.

[0087] Deformable conduit 108 may be any type of conduit structure or other structure that is capable of allowing a thermodynamic boundary to physically move in response to a static pressure differential between fluid in the conduit and fluid to the exterior of the conduit. As previously described, a deformable conduit may comprise at least one moveable barrier of the conduit that enables the conduit to deform. The moveable barrier may correspond to a deformable region or portion(s) of a wall of the conduit. The structure may be deformable in any suitable way(s), for example by being elastic or otherwise comprising elastic material, having one or more movable parts, having a rigid movable portion, etc. In an embodiment, the deformable conduit may comprise a base and a movable portion(s), where the movable portion may move relative to the base in any suitable way or ways, such as by pivoting in a hinge like manner, by moving in a sliding manner, etc. The deformable conduit may be capable of deforming through movement of the movable portion relative to the base. The moveable portion may be moveable relative to the base in a sliding manner. In an embodiment, the movable portion(s) may comprise or consist of a rigid member(s). Accordingly, deformable conduit 108 is deformable in that it comprises at least one moveable barrier. The moveable barrier may at least partly define an internal cavity of deformable conduit 108. Deformable conduit 108 may have any shape and/or orientation including but not limited to straight, divergent, convergent, bent, multiple bends, level, rising, falling, rectangular, crescent, spiral, curved, or any combinations of these. All suitable variations in shape and orientation are contemplated.

[0088] Further, deformable conduit 108 may generally be capable of substantially returning to its original shape or form after deformation. In an embodiment, rather than returning to its original form, the structure is at least be capable of returning substantially to its original volume prior to deformation.

[0089] The example embodiment engine 100 of Figure 4 is now described in terms of states 1, 2, 3, and 4, and stages 1-2, 2-3, 3-4, 4-1 previously described above.

[0090] At the beginning of the boundary movement stage 1-2, deformable conduit 108 of pipe 102 is at its higher, regular volume. This generally corresponds to the volume when the static pressure within deformable conduit 108 is about the same as the static pressure on the outside of deformable conduit 108. The flow of fluid is enabled through pipe 102, for example by having valve 114 in an open state. Fluid is discharged from pipe 102 via outlet region 119, for instance using pump 118. Pump 118 may be used to pump fluid out of pipes 102, 104 at a sufficient rate such that the a static pressure of fluid in a pipe does not exceed a total pressure of the fluid just prior to the fluid entering nozzle 106 of pipe. The total pressure of fluid to the exterior of nozzle 106 is typically at an ambient total pressure.

[0091] In the embodiment of Figure 4, fluid in region 109 of deformable conduit 108 and in the region just to the exterior of pipe nozzle 106 is generally at an ambient fluid static pressure.
Fluid just to the exterior of pipe nozzle 106 is accelerated into deformable conduit 108 through nozzle 106. With the cross-sectional area of deformable conduit 108, taken in a perpendicular direction relative to the flow of fluid F, being less than the cross-sectional area of first end 106a of nozzle 106, the velocity of the fluid increases, per the continuity equation, leading to an increase in the dynamic pressure of the fluid and to a reduction in the static pressure of the fluid to below the ambient static pressure. This velocity increase and static pressure reduction is the Venturi effect. The reduced static pressure may be referred to as a lower static pressure. In this sense, deformable conduit 108 has a smaller cross-sectional area transverse to the flow direction relative to a cross-sectional area of a region of the fluid flow path outside and upstream from deformable conduit 108. Deformable conduit 108 is therefore a constricted choke section of the fluid flow path relative to the fluid flow path in the pipe or device upstream from deformable conduit 108. Additionally or alternatively, in an embodiment such as the one of Figure 4, deformable conduit 108 has a smaller cross-sectional area transverse to the flow direction relative to a cross-sectional area of a region of the fluid flow path outside and downstream from deformable conduit 108. For example, as shown in Figure 4, the cross-sectional area of deformable conduit 108 is less than the cross-sectional area of second region 110b of diffuser 110.

[0092] A higher static pressure of the ambient fluid in region 109 relative to the reduced static pressure of the fluid in deformable conduit 108 causes a net force to act on the thermodynamic boundary defined by a moveable barrier(s) 108a, such as a side(s) or wall(s), of deformable conduit 108. The thermodynamic boundary is a boundary of a thermodynamic system comprising deformable conduit 108. The force acting on moveable barrier 108a moves moveable barrier 108a inwardly relative to deformable conduit 108, thereby reducing the cross-sectional area of deformable conduit 108 and thus contracting the internal volume of deformable conduit 108. This effect is illustrated in the examples of Figures 3A and 3B discussed above.

[0093] As shown in Figure 5, a structure(s) 120 may be physically connected, coupled, integrally formed, or otherwise mechanically linked to moveable barrier 108a of deformable conduit 108 for the purpose of being able to harness energy from the movement of moveable barrier 108a. For descriptive purposes, structure 120 is referred to as a main piston. An energy harnessing device, not shown, may be linked to main piston 120 for harnessing energy from the movement of moveable barrier 108a. However, some embodiments may not comprise a main piston 120. For instance, an energy harnessing device may be mechanically coupled to moveable barrier 108a. Accordingly, description herein of movement of main piston 120 corresponds also to movement of movable barrier 108a such that moveable barrier 108a moves in a similar manner in embodiments that do not have a main piston 120.

[0094] Figure 5 is a diagram of an embodiment showing such a structure 120 in the form of a block or piston. Although the term piston is used herein, the term is not meant to be limited only to pistons. Rather, it is used in an open and general sense. Thus, structure 120 may have any suitable shape and structure for transferring energy from the movement of moveable barrier 108a of deformable conduit 108 elsewhere. Accordingly, the term piston is used to include any suitable structure. Further, piston 120 shown in the figures is merely an example. In other embodiments, piston 120 may be shorter or longer than the length of deformable conduit 108, and may have any other suitable shape.

[0095] In an embodiment, not shown, structure 120 itself may form part or all of moveable barrier 108a, meaning they are one and the same. In this sense, pipe 102 may be considered to not have a piston 120. Rather, the energy of the movement of moveable barrier 108a may be harnessed directly, for example by an energy harnessing device. In another sense, moveable barrier 108a may be considered to be the piston.

[0096] Consequently, the inwardly movement of moveable barrier 108a relative to deformable conduit 108 causes a corresponding inwardly movement of main piston 120. Main piston or structure 120 may be retained and guided by piston guide or guides 122 so that piston 120 is prevented from moving transversely to the axis of its stroke.

[0097] Some or all of the net force acting on the thermodynamic boundary defined by moveable barrier 108a of deformable conduit 108 by the ambient fluid in region 109 may be transferred to moveable barrier 108a via piston 120 when the ambient fluid in region 109 interfaces with piston 120 rather than the exterior of moveable barrier 108a.
The inwardly movement, or power stroke, of piston 120 is constituted of this inward push by the ambient static pressure fluid in region 109.

[0098] As noted above, the movement of moveable barrier 108a, for instance the inwardly movement or stroke of piston 120, may be harnessed in any suitable manner. For example, piston may be coupled to a piston rod and crankshaft-flywheel assembly, or to any other system with some inertia, for power generation for any application. This may include but is not limited to electrical or electronic loads for electrical power generation, for instance piezoelectric loads, or mechanical loads for mechanical power generation. As an example, the harnessing energy from the movement may comprise converting the energy into electrical energy.

[0099] Figure 10 shows another embodiment of a pipe 1002 wherein main piston 1020 is mechanically coupled to piston rods 1032 which in turn are coupled to crankshaft 1034 which in turn is coupled to flywheel 1036. Like in conventional technologies, the flywheel stores some of the power produced as its rotary kinetic inertia while the crankshaft may provide rotary mechanical power to drive any connected loads which may include but are not limited to a dynamo or electricity generator, the propeller of a ship or boat, the propeller of helicopter or aeroplane, the drive train of an automobile or a train. The contraction of the cross-sectional area of deformable conduit 1008 results in further increase in fluid velocity in accordance with the continuity equation thereby resulting in further increase in the difference in static pressure between the fluid within the deformable conduit 1008 and the ambient fluid in region 1009. This inward movement continues until the movement of main piston 1020 has covered the swept volume determined by the designer.

[00100] Turning back to Figure 5, fluid in deformable conduit 108 continues to flow into diffuser 110 where the increase in transverse cross-sectional area results in a reduction in velocity of the fluid, per the continuity equation. Consequently, the static pressure of the slowed fluid recovers, meaning it increases, per the conservation of energy embodied in the Bernoulli principle.

[00101] In some embodiments, such as the one of Figures 4 to 6, pipe 102 may optionally also include a moveable or deformable correction conduit 112, which is sometimes referred to hereafter simply as a correction conduit for brevity. Correction conduit 112 may be generally deformable in a similar sense as described herein with reference to deformable conduit 108.
Accordingly, correction conduit 112 may be any type of conduit structure, or other structure, that is capable of allowing a thermodynamic boundary to physically move in response to received fluid expelled from deformable conduit 108 during the power stroke, which is forced into correction conduit 112. The structure may be deformable in any suitable way(s), for example by being elastic, having one or more movable parts, etc. Further, the structure may generally be capable of substantially returning to its original shape or form after deformation. In an embodiment, rather than returning to its original form, the structure is at least be capable of returning substantially to its original volume prior to deformation.

[00102] Fluid from diffuser 110 may flow into correction conduit 112. In correction conduit 112, part of the energy harnessed in the inward push of main piston 120 may be used to cause a net force to act on a thermodynamic boundary comprising correction conduit 112 and at least partly defined by a moveable barrier(s) 112a, such as a side(s) or wall(s) of correction conduit 112. In the embodiment of Figure 5, this energy is used to in turn push moveable wall 112a outwardly. This outward push of moveable barrier 112a enables the correction conduit 112 to absorb some fluid from diffuser 110, particularly, extra fluid displaced from deformable conduit 108, including but not limited to when the displacement is caused by the inwardly stroke of main piston 120 during the contraction of deformable conduit 108. Other means of fluid displacement from deformable conduit 108 are possible and contemplated. The volume of correction conduit 112 may thus increase in response to the ingress of the extra fluid. The outwardly movement of correction conduit 112 to increase its volume in response to fluid received due to the reduction of the cross-sectional area of deformable conduit 108 may cause an internal volume of the apparatus to remain substantially unchanged as main piston 120 is moved inwardly.

[00103] In an embodiment, moveable barrier 112a may be connected, coupled, or linked to a correction piston or other structure 124. The description of structure or piston 120 above generally applies equally to correction piston or other structure 124.

[00104] Since, by design in at least one embodiment, the swept volumes associated with deformable conduit 108 and correction conduit 112 are equal but the difference in static pressure between the fluid in correction conduit 112 and the external ambient fluid 109 is much less than that between the fluid in deformable conduit 108 and ambient fluid 109, the work consumed by the outwardly, or expansion, stroke of correction piston 124 is much less than the work produced by the inwardly stroke of main piston 120. A thermodynamic system comprising both deformable conduit 108 and correction conduit 112 may in an embodiment, experience boundary movement but no change in volume due to the diametrically opposite changes in volume in deformable conduit 108 and correction conduit 112.

[00105] Similarly to main piston or structure 120, correction piston 124 may be retained and guided by piston guide or guides 126.

[00106] With valve 114 open in this boundary movement stage, the fluid may then flow from correction conduit 112 to pump 118. Pump 118 may do work on the fluid to restore the static pressure substantially back to the ambient static pressure as it pushes the fluid out of an outlet side of pump 118.

[00107] The boundary movement stage may end when the cross-sectional area of the deformable conduit 108 has reached its designed minimum, which generally corresponds to the length of the inwardly stroke of main piston 120.

[00108] As may be appreciated by persons of ordinary skill in the art, thermodynamically, when the static pressure in deformable conduit 108 falls below the static pressure in ambient fluid

109, the thermodynamic boundary of the ambient fluid 109 expands to reduce its own static pressure to equate to the lower static pressure of the fluid in deformable conduit 108. This boundary expansion is an adiabatic expansion, so work is done by the boundary of the ambient fluid 109 and it is this work that may be harnessed as main piston 120 movement for power generation. A reduction in static pressure of the ambient fluid 109 as a consequence of adiabatic expansion would typically also lead to cooling. In various embodiments, the ambient fluid in region 109 is in fluid communication with fluid outside inlet region 105 and just outside outlet region 119, which is generally kept at ambient static pressure by virtue of the gravitational pull of the Earth (i.e. P = hpg) which makes fluid bodies such as the atmosphere and oceans function as a pressure reservoir. This results in a quick recompression of the ambient fluid in region 109, thereby replenishing the compressed fluid energy (enthalpy) of the ambient fluid. The renewability of the ambient compressed fluid energy extracted is therefore contributed to by the gravitational pull of the Earth. In other words, the Earth's gravitational pull replenishes any pressure depletion occurring as a result of the adiabatic expansion of the ambient fluid.
Thermodynamically, any temperature depletion occurring as a result of the adiabatic expansion of the ambient fluid resulting in it cooling below the prevailing environmental temperature is also replenished by heating of the ambient fluid as a consequence of it being in thermal communication with the environment which results in a heat inflow to maintain thermal equilibrium.
The environment functions as a thermal reservoir. Any heat lost to the ambient fluid by the environment may itself be replenished for instance by incoming solar radiation, geothermal heating, and/or also heat production from the use of the extracted energy, for instance energy produced by the technologies according to the present disclosure. Heat production into the environment from the use of the extracted energy may be intentional, for instance when heating a home, or unintentional for instance friction in machines due to inefficiency. These environmental heat sources provide an avenue for thermal energy renewal after adiabatic expansion of the ambient fluid. In summary, both pressure depletion and temperature depletion occurring as a result of ambient fluid adiabatic expansion occurring from the use of the ambient compressed fluid energy technology of the current disclosure are readily renewable.
[00109] The static pressure increase stage 2-3 is now discussed. This stage, also called a flow cessation stage in some embodiments, may begin at the end of the boundary movement stage 1-2 during which the power stroke occurs. During this stage 2-3, the cross-sectional area of deformable conduit 108 is typically at its smallest during the four stage cycle. As a mere example, the cross-sectional area may be at or around 98% of its maximum value. However, other values are possible and contemplated.

[00110] The static pressure increase stage 2-3 may last momentarily relative to the boundary movement stage 1-2.

[00111] In stage 2-3, valve 114 closes to restrict the fluid flow through pipe 102. In an embodiment, valve 114 may be a slide valve that slides perpendicularly to the flow direction to its closed position to restrict the flow from nozzle 106 to the pump 118. The valve may be adapted to close partially to partially restrict the fluid flow, or to close fully to fully restrict, meaning stop, the fluid flow. In this way, the static pressure of the fluid in deformable conduit 108 (e.g. cavity) may be increased above the lower static pressure, meaning the reduced lower static pressure in the boundary movement stage 1-2. The closing of valve 114 and the resulting restriction of fluid flow may, as a mere example in embodiments where the valve is adapted to close fully, cause flow stagnation in which the kinetic pressure of any fluid flowing through pipe 102, including fluid in deformable conduit 108 and/or correction conduit 112 is reconverted to static pressure. In such an example in embodiments where the valve is adapted to close fully, with nozzle 106 remaining in fluid communication with fluid just outside of region 106a of nozzle 106, meaning nozzle 106 is open to ambient, the static pressure of fluid within deformable conduit 108 and correction conduit 112 rises to, or substantially to, at least the ambient static pressure of the fluid just outside of region 106a and ambient fluid 109.

[00112] The restoration stage 3-4 is now discussed. The restoration stage begins at the end of the static pressure increase stage. In the beginning of the restoration stage in this embodiment, flow is already restricted, for instance valve 114 is closed. In this way, the static pressure of the fluid in deformable conduit 108 (e.g. cavity) has been increased above the lower static pressure, meaning the reduced lower static pressure in the boundary movement stage 1-2. As a mere example in embodiments where the valve is adapted to close fully, the static pressures of fluid in deformable conduit 108 and correction conduit 112 are both substantially at least equal ambient static pressure at equilibrium (i.e. post-transient effects). The pressure in ambient fluid in region 109 is also substantially at ambient static pressure.
The cross-sectional area, height and/or volume of deformable conduit 108 is at its smallest during the four stage cycle at the start of the restoration stage 3-4, while the volume of correction conduit 112 is largest during the four stage cycle.

[00113] The restoration stage 3-4 may be considered an expansion stroke in a case of a reciprocating engine, such as for example the embodiment of engine 100.

[00114] In restoration stage 3-4, main piston 120 is moved outward, increasing the cross-sectional area of deformable conduit 108 and returning the cross-sectional area substantially to the original larger area from which the boundary movement stage 1-2 began.
Valve 114 closed in the beginning of the restoration stage to restrict flow in this embodiment, is maintained closed throughout the restoration stage. In this way, the static pressure of the fluid in deformable conduit 108 (e.g. cavity) is maintained above the lower static pressure, meaning the reduced lower static pressure in the boundary movement stage 1-2, as main piston 120 is moved outwardly. In this sense, the deformation of deformable conduit 108 is reversed or undone, thereby restoring the shape of deformable conduit 108 substantially to a shape it had prior to the boundary movement stage 1-2. At this point, the restoration stage ends. The outwardly movement of main piston 120 may be driven in any suitable way, for example by a power stroke of deformable conduit 108 of another pipe in engine 100. It may additionally or alternatively be driven by inertia as a consequence of motion stored in a crankshaft-flywheel assembly, or other device, coupled to main piston 120 in accordance with Newton's first law. The inertia created may be by motion by virtue of previous power strokes.

[00115] In restoration stage 3-4 of the embodiment of engine 100, while main piston 120 is moved outwardly, correction piston 124 may be moved inwardly reducing the volume of correction conduit 112 and returning it substantially to its original smaller volume just prior to the start of the boundary movement stage 1-2. The corresponding outwardly movement of main piston 120 may cause an increase in the volume of deformable conduit 108. The increase and decrease in volumes in this embodiment may substantially match such that the internal volume of the apparatus remains substantially unchanged as main piston 120 is moved outwardly. The inward movement of correction piston 124 may be driven in any suitable way, for instance by the same means driving the outward movement of main piston 120.

[00116] In embodiments designed as a reciprocating engine having two or more pipes according to the present disclosure that are operated alternately, as in engine 100 of Figures 4 to 6, the power stroke of a deformable conduit 108 of a first pipe may be mechanically coupled or linked to the expansion stroke of a deformable conduit 108 of another pipe to result in an equalizing of the durations of the boundary movement and restoration stages, meaning power strokes and expansion strokes.

[00117] The static pressure reduction stage 4-1 is now discussed. The static pressure reduction stage 4-1 begins at the end of the restoration stage 3-4. In the beginning of the static pressure reduction stage 4-1, also called flow enabling stage for the case of some reciprocating engine embodiments, the cross-sectional area of deformable conduit 108 is at its largest in the four stage cycle.

[00118] Similar to the static pressure increase stage 2-3, the static pressure reduction stage 4-1 may last momentarily relative to the boundary movement (i.e. power stroke) stage 1-2.

[00119] In the static pressure reduction stage, valve 114 is opened to enable fluid flow, for example full fluid flow, from nozzle 106 to pump 118. In the static pressure reduction stage 4-1, the enabling of full flow results in part of the static pressure of fluid within pipe 102, including fluid in deformable conduit 108 or correction conduit 112, to be converted to kinetic pressure. With nozzle 106 remaining in fluid communication with fluid just outside of region 106a of nozzle 106, meaning nozzle 106 is open to ambient, the static pressure of fluid within deformable conduit 108 and correction conduit 112 reduces in accordance with the law of conservation of energy embodied in the Bernoulli equation. In this embodiment, the static pressure of the fluid may reduce below the ambient static pressure to the lower static pressure, meaning the reduced lower static pressure in the beginning of the boundary movement stage 1-2.

[00120] The four stage cycle may then be repeated, starting with the boundary movement stage 1-2.

[00121] Figure 7 is an example process flow diagram according to the present disclosure.
The process may begin at block 700 where a cavity defined by a device is exposed to a fluid, the device comprising a moveable barrier at least partly defining the cavity.

[00122] The process proceeds to block 702, where energy from movement of the barrier is harnessed, wherein the movement is caused by a static pressure of fluid in the cavity being at a lower static pressure than an ambient static pressure of fluid on an opposing side of barrier relative to the cavity and wherein the lower static pressure is a consequence of fluid motion.

[00123] The process proceeds to block 704, where, after the movement of the barrier, the static pressure of the fluid in the cavity is increased above the lower static pressure.

[00124] The process proceeds to block 706, where, after the increasing the static pressure of the fluid in the cavity, the barrier is further moved and the static pressure of the fluid in the cavity is maintained above the lower static pressure during the further moving the barrier.

[00125] The process proceeds to block 708, where, after the further moving the barrier, the static pressure of the fluid in the cavity is decreased below the ambient static pressure of fluid on an opposing side of barrier relative to the cavity.

[00126] Some techniques and embodiments according to the present disclosure for optimizing the restoration stage and for handling transient pressure waves are now described.

[00127] With respect to restoration stage 3-4, and with reference to engine 100 of Figure 5, fluid may be required to move from correction conduit 112 during the restoration stage 3-4 as correction conduit 112 contracts while deformable conduit 108 expands. In embodiments where diffuser 110 is a long diffuser, or in other words the distance between correction conduit 112 and deformable conduit 108 is large enough for frictional forces to be very significant in the diffuser, this movement of fluid could be inefficient since energy is required for the flow to overcome friction and friction increases with pipe length. The problem worsens if the frequency of operation of the engine is high since the velocity of flow would be high and it is known that friction increases with velocity. The present disclosure provides techniques and embodiments to reduce or eliminate this inefficiency during restoration stage 3-4.

[00128] With respect to transient pressure waves, it is known that sudden pressurizations and depressurizations such as those undertaken by sudden valve closures and sudden valve openings can result in transient pressure waves which may not be representative of ideal pressures or equilibrium pressures. Where a working fluid is water, this effect is conventionally known as water hammer. It is also known that the initial magnitude of some of these transient pressure waves may be predicted with the Joukowsky Equation. Furthermore, it is known that these waves tend to propagate in a fluid or system at the local sonic speed, time is consumed by such propagation, and the time consumed increases with increasing pipe length.
It is also known that these transient pressure waves may be successively reflected at pipe ends subject to energy losses or dampening, and that in the course of these reflections, a transient pressure wave resulting in a huge pressure rise can eventually generate a reflected wave resulting in a huge pressure drop. Sudden valve closure in a pipe open to ambient in a water hammer event results in: (i) an initial transient pressure wave progressing from the point of valve closure to the end of the pipe open to ambient and generating very high pressures in the pipe as it progresses, (ii) a first reflected pressure wave occurring after the initial pressure wave reaches the ambient opening of the pipe and progressing in a reverse direction as the initial pressure wave but still generating a high pressure although somewhat lower than the initial pressure wave, (iii) a second reflected pressure wave occurring after the first reflected pressure wave reaches the point of valve closure in the pipe and progressing in the same direction as the initial pressure wave but generating a huge pressure drop, a sub-ambient static pressure, (iv) another reflected pressure wave and a repetition of the pressure oscillations until the wave energy is damped out and the pressure in the pipe stabilized to ambient static pressure which is the equilibrium pressure.

[00129] In regard to the present disclosure, if valve 114 is rapidly closed and/or rapidly opened, for example in static pressure increase stage 2-3 and/or static pressure reduction stage 4-1 respectively, some or all of the above described transient issues may arise. As a mere example, in an example embodiment, the time taken for the valve to close may be set to be one-hundredth of the duration of the power stroke or boundary movement stage 1-2 when the frequency of the power stroke (which in this embodiment is the same as the operating frequency of the engine and the operating frequency of successive valve openings or valve closures) is about 13Hz. Operating valve 114 at a high frequency may increase the impact of these undesirable effects on performance. However, for higher power generation by engine 100, it may be necessary to operate the present four stage cycle very rapidly. A huge pressure drop, such as in the aforementioned second reflected transient pressure wave, at a time when a pressure rise is required, such as during the restoration stage, is adverse to engine performance for energy generation. The present disclosure provides techniques and embodiments to optimize power generating efficiency in the presence of transient pressure wave effects.

[00130] Accordingly to the present disclosure, two approaches for handling transient pressure wave effects are provided. A first approach involves a designer taking advantage of the static pressure distribution over space and time of the transient pressure wave. For instance, this may involve optimizing the design to ensure that during the restoration stage, only high transient static pressures occur at main piston 120 and only low transient static pressures occur at correction piston 124. A second approach involves a designer shortening the duration of the transient pressure oscillations relative to the duration of the restoration stage to a level at which the impact of any adverse transient sub-ambient static pressures in the restoration stage are mitigated.

[00131] The first approach may be achieved with careful choices of the values of design and operating parameters of the engine or system, including but not limited to dimensions of various parts, numbers and locations of various parts, materials used for parts, flow rates, ambient working fluid choice and engine operating frequency. Design choices may be selected, for example, using an optimization problem to be solved, for instance using software.

[00132] The second approach may be achieved by using one or more openings, for example in a conduit, that may be selectively opened and closed. Generally, deformable conduit 108 may comprise an opening(s) that is selectively openable and closable to allow for fluid movement between deformable conduit 108 and an ambient side of the deformable conduit. In other embodiments, alternatively or in addition to opening(s) at deformable conduit, an opening(s) may be positioned at location(s) other than at deformable conduit 108, for example nozzle 106 and diffuser 110. In an embodiment, deformable conduit 108 comprises a side opening, and a moveable cover for selectively covering and uncovering the side opening. The moveable cover may be moveable into an uncovered position to allow fluid flow into and/or out of deformable conduit 108 from an ambient side of deformable conduit 108. Cover may be opened, for example, during restoration stage 3-4 or from the start of static pressure increase stage 2-3 to the end of restoration stage 3-4 to allow for a rush of fluid back into deformable conduit 108. In an embodiment, the side opening(s) may be in the form of, or comprise, one or more sliding walls that can move in relation to the conduit in a sliding manner. A wall is the term used in the art for impervious flow cavity boundaries. Figure 8 is a diagram illustrating the concept of sliding walls.
Figures 9A and 9B are diagrams illustrating example embodiments of cavities or conduits having sliding wall(s).

[00133] Figure 8 is a diagram of an embodiment of a conduit 800 through which fluid flows, for example during a power stroke during the boundary movement stage. Conduit comprises walls 802 and 804. Conduit 800 may represent any flow path in the fluid and wall 802 may represent either an immovable wall such as the wall of a nozzle or a moveable wall such as a piston. During the boundary movement stage, the power stroke, the walls are intact and fluid flows axially through conduit 800. Ambient fluid cannot enter from the sides of the cavity since the walls block it. However, at the onset of or just prior to the restoration stage, any of the sliding walls 804 may be pulled or pushed to slide, or otherwise move, out of the way, for example in any of the directions indicated by the arrows, to make it possible for ambient fluid located outside of the pipe to enter into conduit 800 from the sliding sides of conduit 800.

[00134] With reference to the embodiment of engine 100 in Figure 5, the use of sliding walls thus has an impact of not requiring fluid in correction conduit 112 to have to flow to deformable conduit 108 during the restoration stage 3-4. This may improve the energy generation efficiency of pipe 102 by reducing the energy consumed due to friction of fluid flowing from correction conduit 112 to deformable conduit 108. Further, the use of sliding walls may also have an impact on transient pressures, namely it may have an impact of reducing the effective length of the closed pipe which the cavity represents to almost zero. This thereby reduces the time taken for transient pressure wave reflections to occur and transforms at least a part of the pipe from a closed pipe to a U-channel or even an open space. This increases the pace of the stabilization of the pressure in the cavity to ambient static pressure.

[00135] Figures 9A and 9B are diagrams of embodiments of conduits 900 and 950 having pistons 902, 952 and sliding walls 904, 954, respectively. Conduits 900 and/or 950 may be used as or in deformable conduit 108 and/or correction conduit 112 of engine 100 in Figures 4 to 6, which each may have a piston, namely main piston 120 and correction piston 124.

[00136] In conduit 900 of Figure 9A, stationary frame 906 mates with sliding walls 904.
Sliding walls 904 also mate with piston 902. A lubricant, such as engine oil, may be applied to mating surfaces and held within mating grooves 908 to enhance lubrication.
While walls 904 are in a closed position during the boundary movement stage 1-2, at or around the onset of the restoration stage, sliding walls 904 may slide further into stationary frame 906 opening up the cavity defined by conduit 900 to make it easy for ambient fluid to flow from the sides of the cavity to cover the surface of piston 902 to quickly stabilize the static pressure on its surface to ambient.
Sliding walls 904 remain in their open position until the end of the restoration stage at which they slide back into place to close the cavity.

[00137] In conduit 950 in Figure 9B, stationary frame 956 mates with sliding walls 954.
Sliding walls 954 also mate with piston 952. Again, a lubricant, such as engine oil, may be applied to mating surfaces and held within mating grooves 958 to enhance lubrication.
While walls 954 are in a closed position during the boundary movement stage, at or around the onset of the restoration stage, sliding walls 954 may slide with two walls sliding into stationary frame 956 while one wall 954 slides sideways through stationary frame 956. With the sliding walls 954 having slid out of place, conduit 950 is opened up to make it easy for ambient fluid to flow from the exterior of three sides of conduit 950 to cover the piston surface to quickly stabilize its static pressure to ambient. Sliding walls 954 may remain in the open position until the end of the restoration stage at which they slide back into place to enclose the cavity defined by conduit 950.

[00138] Further, conduit 950 illustrates the use of a streamlined piston 952 to reduce the energy consumed by drag as the engine reciprocates. The curved shape of streamlined piston 952 is only meant to be illustrative and not limiting. Where an engine is operated underwater, drag can be a significant inefficiency driver if not optimised in a design.
Various streamlined piston designs including but not limited to those with a more aerofoil-shaped cross-section may be used to reduce piston drag.

[00139] Some general considerations and techniques for improving or optimizing power generation according to the teachings of the present disclosure, such as a pipe or engine, are now described.

[00140] The gross power produced by a pipe 102 is the power produced from main piston 120. The net power produced is generally the power produced from main piston 120 minus the power consumed by correction piston 124, the pump power consumed, the drag power consumed from the motions of main piston 120 and correction piston 124, the power required to operate valve(s) 114, and the power required to operate any sliding walls. The net power equation may be written as:

[00141] Net Power Produced = gross power produced from main piston ¨ correction piston power consumed ¨ pump power consumed ¨ piston drag power consumed ¨ valves and sliding walls power consumed

[00142] For the case of inviscid fluid flow, which is by definition frictionless and rarely observed in fluids with exceptions including liquid Helium at temperatures in the neighbourhood of 2 Kelvin, where quantum behaviour becomes heightened, some of the following techniques may be used to improve net power produced, for example by a pipe 102 or an overall engine 100. One technique is to increase gross power produced by simultaneously increasing area of main piston 120 while increasing static pressure drop at main piston 120 by increasing the velocity at main piston 120 by reducing the cross-sectional area normal to flow at deformable conduit 108. Another technique is to increase gross power produced by increasing the frequency at which the engine runs by using an appropriate gear ratio between engine and load. Another technique is to decrease both correction piston 124 power consumed and pump power by increasing the outlet area 110b of diffuser 110, for instance via a long diffuser to maximise static pressure recovery at the outlet area 110b of diffuser 110 and minimize exit loss at pump 118. A
further technique is to decrease pump power by using a high efficiency pump for pump 118.
Another technique is to reduce piston drag power consumed, and valves and sliding walls power consumed by using streamlined pistons and valves if the reductions provided by the very nature of the inviscid flow is not already sufficient or otherwise desirable.

[00143] For the case of viscous flow where fluid friction exists, however, as evident from the net power equation herein for those skilled in the art, any arbitrary configuration of engine parameters in a design may not yield a renewable energy engine. Such a configuration may result in a device or engine with a negative net power produced, meaning the device consumes more power than it produces. This may especially be the case due to optimization trade-offs. For instance, an attempt to significantly increase the gross power produced by using a narrow cross-section deformable conduit 108, as mentioned above in relation to inviscid flow, may also result in significantly increased pump power consumed since the frictional pressure drop in deformable conduit 108 would increase for instance as predicted by the Darcy-Weisbach Equation due to the decrease in hydraulic diameter and increase in velocity. This may be analogous to designing an airplane; too small a wing and the aeroplane will not have enough lift to fly and on the other hand, too large a wing and the weight of the wing will prevent the aeroplane from lifting. Likewise, too low a speed will cause the aeroplane to not take flight. There are configurations of parameters which may yield flight and others which may not. This is an optimization problem which the aeroplane designer needs to solve.

[00144] One means for optimizing for the case of viscous flow is to reduce the viscous effects, most particularly fluid friction presenting as skin friction or skin drag. In the equation for net power produced, reducing skin drag will have the impact of reducing the correction piston power consumed, pump power consumed, and piston drag power consumed.
Embodiments may use active drag reduction techniques or passive drag reduction techniques including, but not limited to, using superhydrophobic surfaces for walls, generating cavitation bubbles around walls, and/or using drag reducing agents. Where the ambient fluid is water, superhydrophobic surfaces may be used to reduce the magnitude of static pressure losses by for instance, inducing a Cassie-Baxter state with a layer of gas lubricating the fluid flow across parts of the walls and also by generating a low surface energy for the walls. Where the ambient fluid is a liquid, for instance water, cavitation bubbles may be generated around walls bounding high speed flow cavities to reduce the static pressure loss due to friction so as to increase the efficiency or net power produced. This may be done by having sharp protrusions at the beginning of these high speed flow cavities to cause low pressure regions in their wake to result in the vaporisation of the fluid to reduce the wetted area of the wall by the flowing fluid. Drag reducing agents may also be mixed with fluid flowing through the device to reduce fluid friction in high speed flows. At high flow speeds, these may yield non-Newtonian fluid flow behaviours and alter the viscosity of the fluid moving in the device to reduce frictional pressure drops. Drag reducing agents may include drag reducing polymers. For environmental safety reasons, the use of drag reducing agents may be suitable for embodiments in which the fluid in the device is sealed from mixing with fluid in the outside environment, meaning forming a thermodynamically closed system with respect to the outside environment.

[00145] To achieve a positive net power produced for viscous flow, a designer of a specific embodiment according to the present disclosure may choose to solve an optimization problem to explore the design space for a configuration of design choices that achieves a desired net power generation. For instance, an objective function may be to maximize the net power produced by a pipe or engine. The constraints in the optimization problem may include one or more of the magnitude of the prevailing ambient static pressure in the fluid environment the engine is to be operated in, constraints on physical dimensions of various parts of the engine as well as any other constraints the designer may impose on the system. The decision variables in the optimization problem may be the various design parameters which may include one or more of:
the physical dimensions of various parts including their lengths and angles, the swept volume ratio of the main piston, the mass flow rate exiting the pump or engine, the frequency the engine operates at which may be changed for any load speed by changing the gear ratio between the engine speed and that load speed. Alternatively a designer may choose to maximize efficiency subject to a constraint on net power produced. Other optimization models may be used and are contemplated including but not limited to optimizing the power produced per unit volume of device subject to imposed constraints.

[00146] Some other example embodiments according to the present disclosure are now described.

[00147] Figure 10, which was briefly described above, is another embodiment of a pipe 1002. Main piston 1020 is mechanically coupled to piston rods 1032, which in turn are coupled to crankshaft 1034, which in turn is coupled to flywheel 1036. Pipe 1002 may be configured to operate similarly to the pipes 102, 104 of the embodiment of engine 100 of Figure 5. However, there are some differences. In pipe 1002, a datum at the position of an outlet region 1006b of nozzle 1006 that is closest to main piston 1020 is indicated in Figure 10 as P1. A datum at the position of an inlet region 1010a of diffuser 1010 that is closest to main piston 1020 is indicated in Figure 10 as P2. At the beginning of the boundary movement stage, P1 is closer to main piston 1020 than is P2. However, at the end of the boundary movement stage, P2 becomes closer to the main piston than P1. Further, the distance between P1 and P2, indicated as D1 in Figure 10, may be the distance of the power stroke of main piston 1020, namely the stroke distance or height. When main piston 1020 is at the beginning of the power stroke, it is at position P1. When main piston 1020 reaches the end of the power stroke, it is at position P2, which is the position of inlet region 1010a of diffuser 1010 closest to main piston 1020. This ensures that only fluid flow static pressure losses due to contraction of deformable conduit 1008 exist at the points of fluid flow transition from nozzle 1006 to deformable conduit 1008 and from deformable conduit 1008 to diffuser 1010. This may increase efficiency in cases where across similar geometries, the fluid flow static pressure losses due to contraction are lower than fluid flow static pressure losses due to expansion. Further, pipe 1002 also has an angled correction conduit 112 to reduce elbow losses and increase efficiency.

[00148] Figure 11 is another example embodiment of a pipe 1102, wherein nozzle 1106 has a bellmouth shape and deformable conduit 1108 has a diverging shape. A
bellmouth entry tends to reduce loss of pressure as fluid enters pipe 1102 via nozzle 1106.
Deformable conduit 1108 may have a diverging shape in the direction of fluid flow, meaning moving away from nozzle 1106. The choice of the taper angle of deformable conduit 1108 may be one of the decision variables to be explored in the optimization model of the device. The optimization problem and associated governing equations may be set up to account for the possibility of deformable cavities with non-zero taper angles. As a further variant of this example embodiment, the optimization model may be set up to explore taper angles that vary along the axial length of the deformable conduit, for instance having a deformable conduit with a converging-diverging shape, such as a nozzle-throat-diffuser shape.

[00149] Figure 12 is another example embodiment of a pipe 1202 having multiple inlet nozzles 1206 an eductor 1260. Eductor 1260 comprises a motive nozzle 1262 and a choked pipe 1264. Pipe 1202 also comprises deformable conduits 1208, each of which may have one or more main pistons 1220. In this example, there are two deformable conduits 1208, but this is not meant to be limiting.

[00150] Figure 13 is another example embodiment of a pipe 1302 similar to the embodiment in Figure 12. Pipe 1302 comprises deformable conduits 1308 and main pistons 1320. However, unlike pipe 1202 that has inlet nozzles 1206 at each deformable conduit 1208, here the inlet and outlet regions of each deformable conduit 1308 are one and the same, meaning that fluid may enter and leave deformable conduit 1308 via the same channel 1311. Further, unlike in pipes 102, 104 of engine 100 of Figures 5 and 6, main pistons 1320 are not disposed parallel to the main flow direction, indicated by arrow Fl in the figure.

[00151] Further, during boundary movement stage 1-2, there is fluid flow, indicated by arrows F2, from a region within deformable conduits 1308 around main pistons 1320 out of deformable conduits 1308 via channels 1311 into the main flow F even though deformable conduits 1308 are each sealed at one end. This flow is caused due to a low static pressure in flow F, which in turn causes a low static pressure in deformable conduits 1308, which in turn causes main pistons 1320 to move inwardly. The movement of main pistons 1320 displaces fluid within deformable conduits 1308 and causes the flows F2 therein.
Alternatively, if I had done away with 1311 and replaced it with a pump at the end of deformable conduit 1308, I'd have achieved a similar effect. Later in the cycle, the fluid that was displaced out of deformable conduits 1308 may be replaced, for instance in restoration stage 3-4. The fluid replacement may be done in any suitable way, for example using sliding wall(s) and/or by flowing fluid back through channel 1311 in the opposite direction of arrow F2.

[00152] Figure 14 is another example embodiment of a pipe 1402 comprising one or more of an inlet nozzle 1406, deformable conduit 1408, main piston 1420, diffuser 1410, valve 1414 and an optional valve 1416. However, unlike some of the previously described embodiments, pipe 1402 does not use a pump as does the embodiment of, for example, Figure 5 with pump 118. While an embodiment such as the one of Figure 14 may not work when the ambient fluid has a zero bulk velocity, such as may be the case in most lakes, it works in ambient fluids of non-zero bulk velocity such as rivers, wavy sea fronts, oceans with strong currents and windy locations. When placed in a path of a moving fluid with the flow direction being from 1406 to 1414, a low static pressure zone may be generated immediately after diffuser 1410 due to fluid flow phenomena including but not limited to flow separation, wakes, eddies and vortices, and this low static pressure zone provides a pressure gradient similar to the function of a pump to drive flow through the device to overcome fluid flow resistances within the device.
Similar to many embodiments according to the present disclosure, when placed in the path of a moving fluid, while embodiment 1402 may generate power from ambient compressed fluid energy during the boundary movement stage, it may also generate power from the ambient kinetic fluid energy during the restoration stage. This is because for the embodiment variation without the optional valve 1416, the closure of valve 1414 may cause flow stagnation within the deformable conduit and since the dynamic pressure of a moving ambient fluid body is non-zero, the static pressure in the deformable conduit at stagnation may well be above ambient static pressure. This pressure difference may be harnessed by the piston to do work. A potential benefit of an embodiment such as 1402 of Figure 14 is that there is no pump power to be subtracted from the gross power produced. As a result, the net power produced by the pipe or engine may be easily optimized into the positive net power range.

[00153] In a variation (not shown) of embodiment 1402, a correction conduit may be used in accordance with the teachings of this disclosure.

[00154] In another variation of embodiment of pipe 1402, to take advantage of bi-directional flows such as on a seashore where water flows to the shore for instance by waves then recedes from the shore, two valves may be used, valve 1414 at the outlet of diffuser 1410 and another valve 1416 at the inlet of nozzle 1406. Whenever the direction of flow proceeds from nozzle 1406 to diffuser 1410 (e.g. water moving to the seashore when the device is oriented with 1410 diffuser placed closer to the sea shore), the valve 1416 at the beginning of nozzle 1406 is always opened and functions as an open gate to allow the flow in while the valve at the outlet of diffuser 1410, valve 1414, functions as the valve which operates in accordance with the four stages according to the teachings of this disclosure. However, whenever the direction of flow is reversed (e.g. water receding from the sea shore when the device is oriented with 1410 placed closer to the sea shore) and proceeds from diffuser 1410 to nozzle 1406, valve 1414 rather is always opened and functions as an open gate to allow the flow in while the valve at the beginning of nozzle 1406, valve 1416, functions as the valve which operates in accordance with the four stages of the present disclosure. As such, regarding nozzle 1406 and diffuser 1410, what functions as a nozzle and what functions as a diffuser becomes dependent on the flow direction at that particular point in time. The gate function of the valves may be controlled by one or more sensors sensing the direction of fluid flow. Multiple such devices may be arranged to take advantage of flows which are multi-directional, for instance two such devices arranged at a 90 degree angle to each other should be able to take advantage of multidirectional flows in any given plane since any direction in a plane can be decomposed into two directions (i.e. X-axis direction and Y-axis direction for the XY plane).

[00155] Some further example embodiments according to the present disclosure relating to rotary engines are now described.

[00156] Figures 15 and 16 are diagrams of an embodiment relating to rotary engines. This embodiment is intended to merely illustrate another application of the teachings according to the present disclosure and is not meant to be limiting. In particular, the embodiments in Figure 15 and Figure 16 relate to Wankel Engine type adaptations. Figure 15 shows some externally connected features to a rotary engine 1500 while Figure 16 is a cross-sectional view of one end of rotary engine 1500 taken along line 16-16 in Figure 15 showing some internal features. As shown in Figure 16, engine 1500 generally comprises rotor housing 1552, rotor 1554, geared shaft 1556, and rotor gear 1558. Rotor 1554 comprises rotor apexes 1554a, 1554b, 1554c. Rotor 1554 in conjunction with housing 1552 define moving cavities 1582, 1584, 1586, which comprise a moveable thermodynamic boundary and are thermodynamic systems in themselves.

[00157] Rotary engine 1500 embodies the rotary engine equivalent functions of some of the reciprocating engine parts of previously described reciprocating engine embodiments, such as engine 100 in Figures 4 to 6 and Figure 10. The parts include deformable or movable conduit 108, external ambient fluid 109, main piston 120, valve 114, and crankshaft 1034. Engine 1500 may be in fluid communication with external fluid at ambient static pressure at one end via nozzles 1506 and may be in fluid communication with diffusers 1510 at the other end.
Similarly to engine 100 of Figure 5, diffusers 1510 may be in communication with one or more correction conduits, not shown in Figure 15. The one or more correction conduits may be of a reciprocating type such as correction conduit 112 of Figure 5, a rotary adaptation similar to the design in Figure 16, or any other suitable type of correction conduit. Further, similar to engine 100 of Figure 5, one or more pumps may be used to ensure fluid flow. Alternatively, similar to the pipe 1402 of Figure 14, pumps may not be used when the ambient fluid is already flowing.

[00158] In Figure 16, fluid 1562 is the counterpart of the low pressure fluids in conventional Wankel engines. Fluid 1564 on the other hand is the counterpart of the high pressure combusting fluid in conventional Wankel engines and may be disposed at the part of a housing in the engine where the fluid is combusting and expanding.

[00159] In Figure 16, 1566, 1568 and 1570 are sub-ambient static pressure fluid vents at the ends of the prism illustrated in Figure 15, which introduce ambient fluid 1562 at sub-ambient static pressure from nozzles 1506 illustrated in Figure 15 into the engine.
Ambient fluid 1562 shown in Figure 16, introduced from nozzles 1506 moves axially through engine 1500 to diffuser 1510. The sub-ambient static pressure of fluid 1562 arises from the conversion of fluid static pressure to fluid kinetic pressure. Ambient vent 1572 shown in Figure 15 and Figure 16, on the other hand, is a vent that introduces ambient fluid 1509 at ambient static pressure into engine 1500 as fluid 1564.

[00160] Moving cavity 1582 contains fluid 1564 at ambient static pressure by virtue of the ambient vent 1572 in housing 1552 which makes the cavity in fluid communication with ambient fluid 1509. The pressures of fluid 1562 at sub-ambient static pressure and fluid 1564 at ambient static pressure generate forces across the faces 1555 of rotor 1554. Geared shaft 1556 is in contact with rotor 1554 and can rotate when rotor 1554 rotates. The geometry and motion path of rotor 1554 in combination with the geometry and motion path of geared shaft 1556 ensure that the forces due to the pressures on the fluid creates a turning moment on rotor 1554 about geared shaft 1556, which rotates rotor 1554 in the direction of the turning moment, the clockwise direction in Figure 16. This causes movement in moving cavity 1586 when fluid 1562 at sub-ambient static pressure flows through it. This is the boundary movement stage of this rotary engine embodiment and it is the counterpart of boundary movement stage 1-2 of reciprocating engine as illustrated in Figure 1.

[00161] In the course of the rotation, rotor apex 1554c rotates past sub-ambient static pressure fluid vent 1566 while rotor apex 1554a rotates past ambient vent 1572. In the embodiment of engine 100 in Figures 5 to 7, this corresponds to shutting valve 114. This causes the static pressure in moving cavity 1586 to rise to ambient static pressure.
This is the static pressure increase stage of this rotary engine embodiment and it is the counterpart of the static pressure increase stage 2-3 of reciprocating engine as illustrated in Figure 1.

[00162] Moving cavity 1586 continues its rotation while at ambient static pressure to eventually restore itself to a prior position. This is a restoration stage of rotary engine 1500 and it corresponds to restoration stage 3-4 of reciprocating engine as illustrated in Figure 1.

[00163] In the course of the rotation, rotor apex 1554c rotates past ambient vent 1572 while rotor apex 1544a rotates past sub-ambient static pressure fluid vent 1568. In the embodiment of engine 100 in Figures 5 to 7, this is analogous to opening valve 114. This causes the static pressure in moving cavity 1586 to drop to sub-ambient static pressure. This is a static pressure reduction stage of rotary engine 1500 and corresponds to static pressure reduction stage 4-1 of reciprocating engine as illustrated in Figure 1. The cycle then begins again. Energy is harnessed from the motion of rotor 1554, for example to drive a load.

[00164] To enhance or optimise a rotary engine, such as engine 1500 of Figures 15 and 16, the geometry of housing 1552, rotor 1554 and geared shaft 1556 and any other components may be designed with considerations such as, for example, ensuring the kinematics of the assembly is as intended, ensuring the forces on the surfaces of the rotor resulting from the pressures of fluids on the surface of rotor 1554 always results in a net moment of force which causes the rotor 1554 to turn in the intended direction and striving for the net amount of fluid 1564 at ambient static pressure swept into the flow path of the fluids at sub-ambient static pressure during the rotation of rotor 1554 is minimised to near zero so as not to increase the required discharge rate and any associated pump work needed.

[00165] Figure 17 is an example embodiment 1700 wherein the fluid in the device is not ambient fluid but rather a working fluid 1702. It is also an example embodiment wherein the ambient fluid 1704, the surrounding medium, is enclosed to prevent fluid communication with the greater environment which serves as a pressure reservoir 1706. Working fluid conduit 1708, such as a hose(s), may connect an outlet and an inlet of an example device or apparatus according to the present disclosure, such as engine 1710, which comprises first pipe 1712 and second pipe 1714, similar to engine 100 of Figure 4. For instance, inlet region 1712a may be in fluid communication with outlet region 1712b via working fluid conduit 1708. Again, device or apparatus 1710 may take any form, for example reciprocating embodiment 100 or rotary embodiment 1500. Working fluid 1702 re-circulates through engine 1710 via working fluid conduit 1708. Working fluid conduit 1708 may be selected or configured to allow pressure communication with the surrounding medium, namely ambient fluid 1704, but no fluid communication with ambient fluid 1704. Furthermore, ambient fluid 1704 may be enclosed in ambient fluid sac 1716.
Ambient fluid sac 1716 may be selected or configured to allow pressure communication with pressure reservoir 1706, but no fluid communication, in other words, a thermodynamically closed system. Pressure reservoir 1706 may take any form including but not limited to the atmosphere, oceans and lakes. Embodiments with such features may be useful in some situations. For example, using a working fluid, which has better fluid frictional pressure drop characteristics relative to an ambient fluid, may result in higher efficiencies and/or net power produced. Another example is when adding additives such as drag reduction agents to an ambient fluid may improve viscous losses in the device such as by inducing non-Newtonian drag behaviour to increase efficiency but the drag reduction agents need to be contained for economic or environmental reasons.

[00166] Further, the description of other embodiments herein where the fluid in the device or pipe is described as ambient fluid is not meant to be limiting. In other embodiments, the fluid in the device or pipe may be a working fluid rather than ambient fluid.

[00167] Figure 18 is a block diagram of an example computerized device or system 1800 that may be used in implementing one or more aspects or components of an embodiment according to the present disclosure. For example, system 1800 may be used to implement a computing device or system, such as a controller, to be used with a device, system or method according to the present disclosure. These include but are not limited to computerized controllers for controlling an engine and/or pipe, and or any components thereof, according to the present disclosure. Examples include controlling pump discharge, gate identification, device frequency of operation for instance by automatic gear ratio selection, valve opening and closure, and sliding wall opening and closure.

[00168] Computerized system 1800 may include one or more of a computer processor device 1802, memory 1804, a mass storage device 1810, an input/output (I/O) interface 1806, and a communications subsystem 1808. A computer processor device may be any suitable device(s), and encompasses various devices, systems, and apparatus for processing data and instructions. These include, as examples only, one or more of a programmable processor, a computer, a system on a chip, and special purpose logic circuitry such as an ASIC (application-specific integrated circuit) and/or FPGA (field programmable gate array).

[00169] Memory 1804 may be configured to store computer readable instructions, that when executed by processor 1802, cause the performance of operations, including operations in accordance with the present disclosure.

[00170] One or more of the components or subsystems of computerized system 1800 may be interconnected by way of one or more buses 1812 or in any other suitable manner.

[00171] The bus 1812 may be one or more of any type of several bus architectures including a memory bus, storage bus, memory controller bus, peripheral bus, or the like.
Computer processor device 1802 may be in the form of a CPU and/or may comprise any type of electronic data processor. The memory 1804 may comprise any type of system memory such as dynamic random access memory (DRAM), static random access memory (SRAM), synchronous DRAM (SDRAM), read-only memory (ROM), a combination thereof, or the like. In an embodiment, the memory may include ROM for use at boot-up, and DRAM for program and data storage for use while executing programs.

[00172] The mass storage device 1810 may comprise any type of storage device configured to store data, programs, and other information and to make the data, programs, and other information accessible via the bus 1812. The mass storage device 1810 may comprise one or more of a solid state drive, hard disk drive, a magnetic disk drive, an optical disk drive, or the like. In some embodiments, data, programs, or other information may be stored remotely, for example in the cloud. Computerized system 1800 may send or receive information to the remote storage in any suitable way, including via communications subsystem 1808 over a network or other data communication medium.

[00173] The I/O interface 1806 may provide interfaces for enabling wired and/or wireless communications between computerized system 1800 and one or more other devices or systems, such as an ambient static pressure engine according to the present disclosure and/or actuators of its components. Furthermore, additional or fewer interfaces may be utilized. For example, one or more serial interfaces such as Universal Serial Bus (USB) (not shown) may be provided.

[00174] Computerized system 1800 may be used to configure, operate, control, monitor, sense, and/or adjust devices, systems, and/or methods according to the present disclosure.

[00175] A communications subsystem 1808 may be provided for one or both of transmitting and receiving signals. Communications subsystems may include any component or collection of components for enabling communications over one or more wired and wireless interfaces. These interfaces may include but are not limited to USB, Ethernet (e.g. IEEE 802.3), high-definition multimedia interface (HDMI), FirewireTM (e.g. IEEE 1394), ThunderboltTm, WiFiTM
(e.g. IEEE 802.11), WiMAX (e.g. IEEE 802.16), BluetoothTM, or Near-field communications (NFC), as well as GPRS, UMTS, LTE, LTE-A, and dedicated short range communication (DSRC).
Communication subsystem 1808 may include one or more ports or other components (not shown) for one or more wired connections. Additionally or alternatively, communication subsystem 1808 may include one or more transmitters, receivers, and/or antenna elements (none of which are shown).

[00176] Computerized system 1800 of Figure 18 is merely an example and is not meant to be limiting. Various embodiments may utilize some or all of the components shown or described. Some embodiments may use other components not shown or described but known to persons skilled in the art.

[00177] In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments.
However, it will be apparent to one skilled in the art that these specific details are not required. In other instances, well-known electrical structures and circuits are shown in block diagram form in order not to obscure the understanding. For example, specific details are not necessarily provided as to whether the embodiments described herein are implemented as a computer software, computer hardware, electronic hardware, or a combination thereof.

[00178] In at least some embodiments, one or more aspects or components may be implemented by one or more special-purpose computing devices. The special-purpose computing devices may be any suitable type of computing device, including desktop computers, portable computers, handheld computing devices, networking devices, or any other computing device that comprises hardwired and/or program logic to implement operations and features according to the present disclosure.

[00179] Embodiments and operations according to the present disclosure may be implemented in digital electronic circuitry, and/or in computer software, firmware, and/or hardware, including structures according to this disclosure and their structural equivalents.
Embodiments and operations according to the present disclosure may be implemented as one or more computer programs, for example one or more modules of computer program instructions, stored on or in computer storage media for execution by, or to control the operation of, one or more computer processing devices such as a processor. Operations according to the present disclosure may be implemented as operations performed by one or more processing devices on data stored on one or more computer-readable storage devices or media, and/or received from other sources.

[00180] Embodiments of the disclosure may be represented as a computer program product stored in a machine-readable medium (also referred to as a computer-readable medium, a processor-readable medium, or a computer usable medium having a computer-readable program code embodied therein). The machine-readable medium may be any suitable tangible, non-transitory medium, including magnetic, optical, or electrical storage medium including a diskette, compact disk read only memory (CD-ROM), memory device (volatile or non-volatile), or similar storage mechanism. The machine-readable medium may contain various sets of instructions, code sequences, configuration information, or other data, which, when executed, cause a processor to perform steps in a method according to an embodiment of the disclosure.
Those of ordinary skill in the art will appreciate that other instructions and operations necessary to implement the described implementations may also be stored on the machine-readable medium. The instructions stored on the machine-readable medium may be executed by a processor or other suitable processing device, and may interface with circuitry to perform the described tasks.

[00181] Figure 19 is another example embodiment of a pipe 1900, similar to pipe 102 of Figure 6 except that pipe 1900 comprises valve 1902 and valve 1904 respectively immediately upstream and downstream of deformable conduit 108. Pump 118 may impose a pressure gradient to cause fluid in the liquid phase to move in pipe 1900. In one mode of operation, in stage 4-1 the static pressure reduction stage, valves 1902, 1904 and 114 are open enabling the pressure gradient imposed by pump 118 to cause fluid to move through the pipe thereby generating a lower static pressure relative to ambient static pressure, at deformable conduit 108 in accordance with the Venturi effect and Bernoulli equation. With sufficiently low static pressure at deformable conduit 108, at least a part of the liquid fluid changes into the gaseous phase. The mode of change to the gaseous phase may include but not be limited to by vaporisation of the liquid in accordance with boiling under reduced pressure when the prevailing static pressure is lower than the saturated vapour pressure of the liquid at its prevailing temperature or by effervescence of prior dissolved gasses within the liquid. Various enhancements such as employing sharp edges and protrusions within the flow path may facilitate the liquid-gas phase change as known by those skilled in the art of cavitation.

[00182] The gas which usually occupies more volume then corresponding liquid on a per unit mass basis (matter in gaseous phase generally having higher specific volume than matter in liquid phase), then displaces at least part of the liquid within deformable cavity 108. The fluid displaced may be moved into a correction conduit 112 or moved away by pump 118. In stage 1-2 the boundary movement stage, valve 1902 and valve 1904 are closed to trap the low pressure gaseous fluid. For this closure, the valves may be closed simultaneously or valve 1902 upstream of deformable conduit may be closed before valve 1904 downstream of deformable conduit to cause and take advantage of further lower static pressure and liquid to gas phase change through transient pressure effects. The closure of valve 1902 and 1904 would cause bulk fluid movement through deformable conduit 108 to stop and consequently some static pressure rise as dynamic pressure becomes converted to static pressure, however with sufficiently low static pressure and a large volume of gas, the trapped fluid in deformable conduit 108 will still be at a lower static pressure relative to ambient static pressure. With the fluid in deformable conduit 108 being at lower static pressure than ambient fluid 109, piston 120 moves inwardly similarly to pipe 102 of Figure 6. The inwardly movement of the piston may be facilitated by cavitation-like effects where as static pressure rises in deformable conduit 108 due to the compression of the gaseous phase by the inwardly movement of piston 120, the effervesced gases and vapour implode to condense back into the liquid phase, rapidly freeing up the volume they occupied and enabling the piston to move through a larger swept volume to increase the energy harnessed from the piston and/or the efficiency of the device. In another mode of operation, the transition of fluid from a liquid phase to a gaseous phase may be caused by the closure of valve 1902 through transient pressure effects. In this mode of operation, the function of valve 1902 includes contributing to causing the phase change rather than just trapping the gas produced from a phase change. In yet another mode of operation, the transition of fluid from a liquid phase to a gaseous phase in deformable conduit 108 may be caused by transient pressure effects arising from sudden depressurization when valves 1904 and 114 are both suddenly opened while valve 1902 is closed, causing fluid movement in deformable conduit 108 on a transient scale which may be eventually stopped by the closure of valve 1904 as the gaseous fluid is trapped. Variations of this embodiment may include using the shape and orientation of pipe 1900 to enhance the liquid to gas phase change and/or the trapping of the gaseous phase. All suitable variations in mode of operation, shape and orientation are contemplated.

[00183] The modes of operation of pipe 1900 in Figure 19 highlight a case according to the present disclosure in which energy is harnessed from movement of a barrier, here movable barrier 108a of deformable conduit 108, wherein the movement is caused by a static pressure of fluid in the cavity being at a lower static pressure than an ambient static pressure of fluid on an opposing side of barrier relative to the cavity, such as region 109, and wherein the lower static pressure is a consequence of fluid motion which occurred prior to the movement of the barrier.
The teachings of this technique may be used in any embodiments according to the present disclosure, including the rotary engine embodiments such as engine 1500.

[00184] For ease of reference, any technologies comprising the techniques described herein may be referred to as 'Ambient Compressed Fluid Energy (ACFE) Technology'.

[00185] For ease of reference and contrast with existing engines, an engine using techniques comprising the techniques described herein may be referred to as Barnieh Engine'.

[00186] For ease of reference and contrast with existing thermodynamic cycles, thermodynamic cycles comprising the techniques described herein may be referred to as `Barnieh Cycle'.

[00187] Some embodiments described herein relate to reciprocating engines. However, as noted previously, the scope of the present disclosure is not intended to be limited to reciprocating engines. The teachings of the present disclosure may be used or applied in or with other types of energy generation devices or systems. Similarly, some embodiments described herein relate to a case where the fluid within the device is ambient fluid.
However, as noted previously, the scope of the present disclosure is not intended to be limited to the case where the fluid within the device is ambient fluid. The teachings of the present disclosure may be used or applied in or with a case where the fluid within the device is not ambient fluid, for example a working fluid whose source is not the surrounding medium.

[00188] Some embodiments described herein may relate to the case of one valve disposed at a specific location within the device. Examples include valves 114, 1414, 1416. However, as noted previously, the scope of the present disclosure is not intended to be limited to one valve disposed at a specific location. The teachings of the present disclosure may be used or applied in or with a case where there is more than one valve. The teachings of the present disclosure may also be used or applied in or with a case where a valve(s) is disposed in other location(s) of the device. Some embodiments described herein may relate to when the lower static pressure which is a consequence of fluid motion is only present when a fluid is still moving. However, as noted previously, the scope of the present disclosure is not intended to be limited to the case where the lower static pressure is only present when a fluid is still moving.
The teachings of the present disclosure may be used or applied in or with a case where the lower static pressure yielded as a consequence of fluid motion is present when a fluid is not moving, for example a lower static pressure caused by previous fluid motion in a now stationary fluid or a lower static pressure caused by previous fluid motion in a cavity now containing stationary fluid may persist.
An example is embodiment 1900. Further, energy generated according to the present disclosure may be used in any number of suitable ways, including to power engines and motors, and for power generation in any other suitable application. This may include but is not limited to electrical or electronic loads for electrical power generation, for instance piezoelectric loads, or mechanical loads for mechanical power generation. Energy generated according to the present disclosure may be used in any number of suitable ways, including but not limited to power various transportation vehicles for transporting goods and people over sea, air and land for example ships, aeroplanes and automobiles for example by direct mechanical energy, by converting the energy into electrical energy and/or by converting the energy into chemical energy for instance fuels produced with the energy including but not limited to hydrogen produced by various processes including but not limited to the electrolysis of water. Energy generated according to the present disclosure may also be used in any number of suitable ways, including but not limited to converting the energy into electrical energy and selling or commercializing the electricity to consumers, converting the energy into chemical energy for instance fuels produced with the energy including but not limited to hydrogen produced by various processes including the electrolysis of water and selling or commercializing the chemical energy such as fuels for example hydrogen to consumers. Further, the present teachings may be used in any other types of suitable applications and in other fields.

[00189] In an embodiment, one or more kits may be provided that comprise components of a device, apparatus, and/or system, according to the present disclosure. In an embodiment, in a kit, a device, apparatus, and/or system may be in an at least partially unassembled form.
Further, a kit may comprise two or more kits. In an embodiment, a kit comprises a collection of parts that are assemble-able to form an apparatus. In an embodiment, the kit may be assembled to form, or at least partly form, a rotary engine.

[00190] The structure, features, accessories, and alternatives of specific embodiments described herein and shown in the Figures are intended to apply generally to all of the teachings of the present disclosure, including to all of the embodiments described and illustrated herein, insofar as they are compatible. In other words, the structure, features, accessories, and alternatives of a specific embodiment are not intended to be limited to only that specific embodiment unless so indicated.

[00191] In addition, the steps and the ordering of the steps of methods and data flows described and/or illustrated herein are not meant to be limiting. Methods and data flows comprising different steps, different number of steps, and/or different ordering of steps are also contemplated. Furthermore, although some steps are shown as being performed consecutively or concurrently, in other embodiments these steps may be performed concurrently or consecutively, respectively.

[00192] For simplicity and clarity of illustration, reference numerals may have been repeated among the figures to indicate corresponding or analogous elements.
Numerous details have been set forth to provide an understanding of the embodiments described herein. The embodiments may be practiced without these details. In other instances, well-known methods, procedures, and components have not been described in detail to avoid obscuring the embodiments described.

[00193] The above-described embodiments are intended to be examples only.
Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope, which is defined solely by the claims appended hereto.

Claims

CLAIMS:

1. An apparatus, comprising:
a moveable barrier at least partly defining a cavity, the cavity for receiving a fluid, wherein the barrier is configured for movement in response to a static pressure of fluid in the cavity being at a lower static pressure than an ambient static pressure of fluid on an opposing side of barrier relative to the cavity, and wherein the lower static pressure is a consequence of fluid motion;
means for increasing the static pressure of the fluid in the cavity above the lower static pressure after movement of the barrier;
means for further moving the barrier, after the increasing the static pressure of the fluid in the cavity, and means for maintaining the static pressure of the fluid in the cavity above the lower static pressure during the further moving the barrier; and means for decreasing, after the further moving the barrier, the static pressure of the fluid in the cavity below the ambient static pressure of fluid on an opposing side of barrier relative to the cavity.

2. The apparatus of claim 1, further comprising an energy harnessing device linked to the moveable barrier for capturing energy from the movement of the barrier.

3. The apparatus of claim 1 or 2, wherein the means for increasing the static pressure of the fluid comprise a valve for selectively restricting the movement of fluid through or outwardly from the apparatus.

4. The apparatus of claim 1 or 2, wherein the means for decreasing the static pressure of the fluid comprise a valve for selectively increasing the movement of fluid through or outwardly from the apparatus.

5. The apparatus of any one of claims 1 to 4, comprising a deformable conduit, wherein the movable barrier is a deformable region of the deformable conduit, and wherein the movement of the barrier involves an inwardly movement of the deformable conduit.

6. The apparatus of claim 5, wherein the means for further moving the barrier is configured to at least partly restore the deformable conduit by reversing the inwardly movement.

7. The apparatus of claim 5 or 6, wherein the means for decreasing the static pressure of the fluid in the cavity are configured to enable a movement of the fluid through or outwardly from the deformable conduit.

8. The apparatus of claim 7, wherein the deformable conduit has a smaller cross-sectional area transverse to a fluid flow path through the deformable conduit relative to a cross-sectional area of a region of the fluid flow path in the apparatus upstream and/or downstream from the deformable conduit.

9. The apparatus of any one of claims 5 to 8, further comprising a deformable correction conduit for receiving fluid from the deformable conduit, wherein the fluid is received in response to the inwardly movement of the deformable conduit, wherein the deformable correction conduit is adapted to move outwardly to increase a volume of the deformable correction conduit in response to the receiving of the fluid.

10. The apparatus of claim 9, wherein the deformable correction conduit is adapted to return toward a previous shape by moving inwardly as the deformable conduit is moved outwardly.

11. The apparatus of claim 9 or 10, wherein the outwardly movement of the deformable correction conduit to increase the volume of the deformable correction conduit in response to fluid received from the deformable conduit causes an internal volume of the apparatus to remain substantially unchanged with the inwardly movement of the deformable conduit.

12. The apparatus of any one of claims 5 to 11, wherein the deformable conduit comprises an elastic wall capable of deformation.

13. The apparatus of any one of claims 5 to 12, wherein the deformable conduit comprises an opening that is selectively openable and closable to allow for fluid movement between the deformable conduit and an ambient side of the deformable conduit.

14. The apparatus of any one of claims 5 to 13, further comprising a pump for generating or enhancing fluid movement through and/or outwardly from the apparatus.

15. The apparatus of any one of claims 1 to 14, configured such that the movement of the barrier, the increasing the static pressure of the fluid, the further moving the barrier, and the decreasing the static pressure of the fluid are repeated in a cycle.

16. The apparatus of any one of claims 1 to 4 and 15, wherein the apparatus is a rotary engine, the moveable barrier is a rotor of the rotary engine, and the movement is rotation of the rotor, and wherein the cavity is defined by the rotor and a rotor housing.

17. The apparatus of claim 16, wherein the means for increasing the static pressure of the fluid comprises the rotor, wherein the rotor is adapted to be rotated such that the cavity is moved out of fluid communication from a sub-ambient fluid intake vent and the cavity is moved into fluid communication with an ambient fluid intake vent.

18. The apparatus of claim 17, wherein the means for decreasing the static pressure of the fluid comprises the rotor, wherein the rotor is adapted to be rotated such that the cavity is moved into fluid communication with the sub-ambient fluid intake vent.

19. The apparatus of any one of claims 1 to 18, configured to receive as the fluid a working fluid that is separate from an ambient fluid to be located on an opposing side of barrier relative to the cavity.

20. A method, comprising:
exposing a cavity defined by a device to a fluid, the device comprising a moveable barrier at least partly defining the cavity;
harnessing energy from movement of the barrier, wherein the movement is caused by a static pressure of fluid in the cavity being at a lower static pressure than an ambient static pressure of fluid on an opposing side of barrier relative to the cavity, and wherein the lower static pressure is a consequence of fluid motion;
increasing, after the movement of the barrier, the static pressure of the fluid in the cavity above the lower static pressure;
further moving the barrier, after the increasing the static pressure of the fluid in the cavity, and maintaining the static pressure of the fluid in the cavity above the lower static pressure during the further moving the barrier; and decreasing, after the further moving the barrier, the static pressure of the fluid in the cavity below the ambient static pressure of fluid on an opposing side of barrier relative to the cavity.

21. The method of claim 20, wherein the increasing the static pressure of the fluid involves selectively restricting the movement of fluid through or outwardly from the device.

22. The method of claim 20 or 21, wherein the decreasing the static pressure of the fluid in the cavity involves selectively increasing the movement of fluid through or outwardly from the device.

23. The method of any one of claims 20 to 22, wherein the device comprises a deformable conduit at least partly defining the cavity, wherein the movable barrier is a deformable region of the deformable conduit, and wherein the movement of the barrier involves an inwardly movement of the deformable conduit.

24. The method of claim 23, wherein the further moving the barrier involves at least partly restoring the deformable conduit by reversing the inwardly movement.

25. The method of claim 23 or 24, wherein the decreasing the static pressure of the fluid in the cavity involves moving the fluid through or outwardly from the deformable conduit.

26. The method of claim 25, wherein the deformable conduit has a smaller cross-sectional area transverse to a fluid flow path through the deformable conduit relative to a cross-sectional area of a region of the fluid flow path in the device upstream and/or downstream from the deformable conduit.

27. The method of any one of claims 23 to 26, further comprising:
receiving fluid from the deformable conduit into a deformable correction conduit in response to the inwardly movement of the deformable conduit, wherein the deformable correction conduit is adapted to move outwardly to increase a volume of the deformable correction conduit in response to the received fluid.

28. The method of claim 27, wherein the deformable correction conduit is adapted to return toward a previous shape by moving inwardly as the deformable conduit is moved outwardly.

29. The method of claim 27 or 28, wherein the outwardly movement of the deformable correction conduit to increase the volume of the deformable correction conduit in response to fluid received from the deformable conduit causes an internal volume of the device to remain substantially unchanged with the inwardly movement of the deformable conduit.

30. The method of any one of claims 23 to 29, wherein the deformable conduit comprises an elastic wall capable of deformation.

31. The method of any one of claims 23 to 30, further comprising selectively opening and closing an opening in the deformable conduit to allow for fluid movement between the deformable conduit and an ambient side of the deformable conduit.

32. The method of any one of claims 23 to 31, further comprising using a pump to generate or enhance fluid movement through and/or outwardly from the device.

33. The method of any one of claims 20 to 32, wherein the operations of claim 20 are repeated in a cycle.

34. The method of any one of claims 20 to 33, wherein the harnessing energy from movement of the barrier comprises mechanically linking the barrier to an energy harnessing device.

35. The method of any one of claims 20 to 22, wherein the device is a rotary engine, the moveable barrier is a rotor of the rotary engine, and the movement is rotation of the rotor.

36. The method of claim 35, wherein the increasing the static pressure of the fluid comprises rotating the rotor such that the cavity is moved out of fluid communication from a sub-ambient fluid intake vent and the cavity is moved into fluid communication with an ambient fluid intake vent.

37. The method of claim 36, wherein the decreasing the static pressure of the fluid comprises rotating the rotor such that the cavity is moved into fluid communication with the sub-ambient fluid intake vent.

38. A kit, comprising:
a collection of parts that are assemble-able to form an apparatus, the apparatus comprising:
a moveable barrier configurable to at least partly define a cavity, the cavity for receiving a fluid, wherein the barrier is configurable for movement in response to a static pressure of fluid in the cavity being at a lower static pressure than an ambient static pressure of fluid on an opposing side of barrier relative to the cavity, and wherein the lower static pressure is a consequence of fluid motion;
means configurable for increasing the static pressure of the fluid in the cavity above the lower static pressure after movement of the barrier;
means configurable for further moving the barrier, after the increasing the static pressure of the fluid in the cavity, and means configurable for maintaining the static pressure of the fluid in the cavity above the lower static pressure during the further moving the barrier; and means configurable for decreasing, after the further moving the barrier, the static pressure of the fluid in the cavity below the ambient static pressure of fluid on an opposing side of barrier relative to the cavity.

39. The kit according to claim 39, further comprising an energy harnessing device linkable to the moveable barrier for capturing energy from the movement of the barrier.

40. The kit according to claim 39 or 40, wherein the means for increasing the static pressure of the fluid comprise a valve for selectively restricting the movement of fluid through or outwardly from the apparatus.

41. The kit according to claim 39 or 40, wherein the means for decreasing the static pressure of the fluid comprise a valve for selectively increasing the movement of fluid through or outwardly from the apparatus.

42. The kit according to any one of claims 39 to 41, comprising a deformable conduit, wherein the movable barrier is a deformable region of the deformable conduit, and wherein the movement of the barrier involves an inwardly movement of the deformable conduit.

43. The kit according to claim 42, wherein the means for further moving the barrier is configured to at least partly restore the deformable conduit by reversing the inwardly movement.

44. The kit according to claim 42 or 43, wherein the means for decreasing the static pressure of the fluid in the cavity are configured to enable a movement of the fluid through or outwardly from the deformable conduit.

45. The kit according to claim 44, wherein the deformable conduit has a smaller cross-sectional area transverse to a fluid flow path through the deformable conduit relative to a cross-sectional area of a region of the fluid flow path in the apparatus upstream and/or downstream from the deformable conduit.

46. The kit according to any one of claims 42 to 45, further comprising a deformable correction conduit for receiving fluid from the deformable conduit, wherein the fluid is received in response to the inwardly movement of the deformable conduit, wherein the deformable correction conduit is adapted to move outwardly to increase a volume of the deformable correction conduit in response to the receiving of the fluid.

47. The kit according to claim 46, wherein the deformable correction conduit is adapted to return toward a previous shape by moving inwardly as the deformable conduit is moved outwardly.

48. The kit according to claim 46 or 47, configured such that the outwardly movement of the deformable correction conduit to increase the volume of the deformable correction conduit in response to fluid received from the deformable conduit is configured to cause an internal volume of the apparatus to remain substantially unchanged with the inwardly movement of the deformable conduit.

49. The kit according to any one of claims 42 to 48, wherein the deformable conduit comprises an elastic wall capable of deformation.

50. The kit according to any one of claims 42 to 49, wherein the deformable conduit comprises an opening that is selectively openable and closable to allow for fluid movement between the deformable conduit and an ambient side of the deformable conduit.

51. The kit according to any one of claims 42 to 50, further comprising a pump for generating or enhancing fluid movement through or outwardly from the apparatus.

52. The kit according to any one of claims 39 to 51, configured such that the movement of the barrier, the increasing the static pressure of the fluid, the further moving the barrier, and the decreasing the static pressure of the fluid are repeated in a cycle.

53. The kit according to any one of claims 39 to 42 and 52, wherein the apparatus is a rotary engine, the moveable barrier is a rotor of the rotary engine, and the movement is rotation of the rotor, and wherein the cavity is defined by the rotor and a rotor housing.

54. The kit according to claim 53, wherein the means for increasing the static pressure of the fluid comprises the rotor, wherein the rotor is adaptable to be rotated such that the cavity is moved out of fluid communication from a sub-ambient fluid intake vent and the cavity is moved into fluid communication with an ambient fluid intake vent.

55. The kit according to claim 54, wherein the means for decreasing the static pressure of the fluid comprises the rotor, wherein the rotor is adaptable to be rotated such that the cavity is moved into fluid communication with the sub-ambient fluid intake vent.

56. The kit according to any one of claims 39 to 55, configured to receive as the fluid a working fluid that is separate from an ambient fluid to be located on an opposing side of barrier relative to the cavity.