CA1106728A - Utilisation of wave motion - Google Patents
Utilisation of wave motionInfo
- Publication number
- CA1106728A CA1106728A CA317,303A CA317303A CA1106728A CA 1106728 A CA1106728 A CA 1106728A CA 317303 A CA317303 A CA 317303A CA 1106728 A CA1106728 A CA 1106728A
- Authority
- CA
- Canada
- Prior art keywords
- resonator
- water
- pressure
- air cushion
- fluid flow
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000033001 locomotion Effects 0.000 title claims abstract description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 55
- 239000012530 fluid Substances 0.000 claims abstract description 17
- 238000000034 method Methods 0.000 claims description 5
- 208000036366 Sensation of pressure Diseases 0.000 claims 1
- 230000003019 stabilising effect Effects 0.000 claims 1
- 230000002441 reversible effect Effects 0.000 description 5
- 238000007667 floating Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000009194 climbing Effects 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 239000013535 sea water Substances 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000008400 supply water Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03B—MACHINES OR ENGINES FOR LIQUIDS
- F03B13/00—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates
- F03B13/12—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates characterised by using wave or tide energy
- F03B13/14—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates characterised by using wave or tide energy using wave energy
- F03B13/24—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates characterised by using wave or tide energy using wave energy to produce a flow of air, e.g. to drive an air turbine
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/30—Energy from the sea, e.g. using wave energy or salinity gradient
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Other Liquid Machine Or Engine Such As Wave Power Use (AREA)
- Hybrid Cells (AREA)
- General Induction Heating (AREA)
Abstract
ABSTRACT
A power unit comprises a resonator having a mouth located in the sea and containing a body of water and an air cushion above the body of water. This resonator can have a neck defining a relatively small flow area com-pared with the surface area of the body of water immediately below the cushion. The air cushion is controlled to cause the water to resonate in response to pressure fluctuations resulting from wave motions in the sea, thereby developing fluctuations of increased pressure. The unit is constructed so that the increased pressure fluctuations create a fluid flow, which is then utilised in a suitable manner.
A power unit comprises a resonator having a mouth located in the sea and containing a body of water and an air cushion above the body of water. This resonator can have a neck defining a relatively small flow area com-pared with the surface area of the body of water immediately below the cushion. The air cushion is controlled to cause the water to resonate in response to pressure fluctuations resulting from wave motions in the sea, thereby developing fluctuations of increased pressure. The unit is constructed so that the increased pressure fluctuations create a fluid flow, which is then utilised in a suitable manner.
Description
7~
THIS INVENTION relates to the utilisation of wave motion, particularly the motion of sea waves.
In the past attempts have been made to utilise energy from the sea. There are three basic ways in which these attempts have been made. Firstly, floats have been used to follow the wave motion and to generate power.
Secondly, sea waves have been used, for example, by generating power as sea water flows over or through a dam.
The third basic method, which has been considered for the 10 purpose of generating a minimal amount of power, is to use sea water to blow air through an orifice in, for example, - a floating buoy to cause a whistling sound.
These prior proposals have only met with limited success and it is an aim of the present invention to 15 provide an improved method and unit for utilising power from the sea.
According to the invention, there is provided a power unit comprising a resonator having a mouth located in the sea and containing a body of water and an air 20 cushion above the body of water; the air cushion being - . ~
: . .
.
:
controlled to cause the water to resonate in response to pressure fluctuations resulting from wave motions in the sea, thereby developing fluctuations of increased pressure, said controlling means comprising a sensor in the resonator and a compressor for providing adjustment of air pressure in the resonator in response to pressur~e sensed by the sensor; and the unit being constructed so that the increased pressure fluctuations create a fluid flow; and means for utilising the fluid flow so created.
The resonator may be a Helmholtz resonator and have a neck defining a relatively small flow area compared with the surface area of the body of water immediately below the cushion.
The means for controlling the air cushion control the pressure of the air forming the air cushion for tuning the resonator to provide a suitable resonance in response to wave motion.
The means for controlling the fluid flow may include an outlet above the neck of the resonator and through which water can be forced, for example, into a pressure tank~ The water from the pressure tank may be fed to a turbine for driving an alternator or generator to generate power. Alternatively, the mouth of the reson~tor may be provided with vanes for directing water flowing from the mouth. This water flow can be used, for example, to propel a boat or ship.
The invention also extends to a method of generating power, which comprises providing a resonator having a mouth located in the sea so that the resonator contains a body of water and an air cushion; said mouth having a small flow area compared with a surface area of said body of water immediately below said air cushion; sensing the pressure in said air cushion; controlling the pressure of the air cushion in response to the pressure sensed in said air cushion; thereby causing the water in the resonator to resonate in response to pressure fluctuations resulting from wave motions in the sea so that fluetuations of inereased pressure are developed; eausing the increased pressure fluetuations to ereate a fluid flow; and utilizing the fluid flow so created to generate power.
The invention further e~tends to an apparatus for use in a power unit, the apparatus having a chamber for reeeiv-ing an air eushion and a body of water below the air eushion and having a mouth for loeating below sea level for plaeing a body of water in the chamber in direct fluid eommunication with the sea; a sensor for sensing pressure in the ~hamber; air eontrol means for increasing or decreasing air pressure in the chamber to create resonant conditions and means for utilising fluid flow created as a result of said resonant conditions.
The apparatus can comprise a pair of resonators Or different heights and arranged substantially side-by-side with sensors in both of the resonators and means for controlling the pressures of air cushions therein for normally maintaining resonant conditions in said resonators.
~' 7~i~
Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
Figure la is a schematic diagram of a resonator having a mouth located below sea level and Figure lb is an - analogous electrical circuit;
Figure 2 is a schematic diagram showing a power unit;
.
Figure 3a is a schematic diagram showing a 1~ propulsion system;
Figure 3b shows an alternative position of part of the system;
Figures 4a, 4b and 4c are provided to illustrate tuning of a resonator;
Figure 5 shows diagrammatically one form of generating station; and Figure 6a and 6b show flow-directing vanes.
As shown in Figure l, an ocean-swell-tuned Helmholtz resonator lO is substantially in the form of an inverted cylinder having a closed upper end and an open lower end providing a mouth 12. The mouth 12 of the resonator is located below sea level and, as shown, the resonator is filled with ater to a variable level 14. An air cushion 16 is formed above the water level 14.
The still water level of the ocean is shown at 18 and a wave is shown at 20, the height of the wave peak being illustrated at 22.
The column of water in the resonator is acted on 10 by the wave motion and, by suitably controlling the pressure of the air cushion 16, it is possible to ensure that the water in the resonator will resonate at the wave frequency.
Thus, it is possible to develop relatively intense pressure fluc.uations in the air cushion and the water below.
In order to determine the characteristics of such a resonator, it is possible to use an analogous electrical circuit as shown in Figure lb. This circuit includes a power generator 24 for generating a voltage which is analo-gous to the ocean wave pressure fluctuations 20; and an inductance L which is analogous to the mass of the water column in the resonator. Capacitance C represents the air cushion 16 above the mass of water and energy lost through radiation of waves from the mouth of the resonator is represented by the energy lost through resistance R. The : ' :
.. .
v~
- `
energy extracted from the resonator for power generation purposes, together wi-th coinciden-tal losses such as viscous drag are represented by resistance Rl.
The power generation unit of Figure 2 is based on the principles illustrated in connection with Figures la and lb. The unit includes a Helmholtz resonator 26 having a primary chamber 28 and a downwardly extending neck 30.
The lower end of the neck 30 defines a mouth 32. The resonator is filled with a body of water up to a movable water level 34 and an air cushion 36 is formed above the body of water. A pressure control system 35 is provided for controlling the pressure of the air defining the air cushion 36 for tuning the resonator. The system 35 has a sensor 35.l mounted in the air cushion 36 and this i9 connected to a control device 35.2 for controlling the operation of a reversible compressor 35.3. The reversible compressor can increase or decrease the pressure in the cushion 36 until resonance is obtained. The resonator is mounted with the neck extending below sea level.
The resonator lO is connected to a pressure tank 38 by an outlet 40 including a non-re-turn valve 42. The valve is designed to allow substan-tially full-bore flow through the outlet 40.
As shown in -the drawing, the tank 38 has an air cushion 44 at its upper end and this is intermittently compressed by flow of water through the outlet 40 into the .
tank and serves to stabilise the flow of water from the pressure tank through an outlet 46 to a turbine 48. The turbine may be any standard water turbine and is connected to drive an alternator 50, another elec-trical generator or any other suitable equipment.
.
A plurality of resonators can be arranged to feed the pressure tank if desired.
When the water in the resonator is subjected to wave motion, the mass of water resonates with the compliance 10 of the air above the water. Intense pressure fluctuations are developed above the neck of the resonator and water is fGrced through the outlet 40 and valve 42 into the tank.
The water leaves the tank through the outlet 46 and then drives the turbine 48.
As shown in Figure 5, a generating station com-prises a floating hull 55 in which a plurality of resonators 26 like that of Figure 2 are mounted. Each of the resonators is arranged with its mouth 32 opening through the bottom of the hull at a location which is permanently below sea 20 level. The resonators are arranged in pairs with outlets 40 of the resonators of each pair communicating with a single pressure tanks 38. The pressure tanks are again arranged to supply water to drive -the turbine 48 and thus the generator 50. The hull 50 can be moved at any suitable 25 location. Naturally, the generating station need not be a floating one.
~ o~
Referring now to Figures 3a and 3b, a resonator 26 which is similar to the resonator of Figure 2 is mounted in a ship or boat (not shown). The parts of this resonator are indicated by the same reference numerals as those used - 5 in Figure 2. The resonator is again provided with a pressure control system for controlling the pressure of the air cushion 36 and the mass of the water in the neck 30 again resonates with the compliance of the air cushion.
A board or similar device 52 is pivotally mounted 10 on the inside wall of the neck at one side of the neck.
This board is connected to a set of streamlined vanes 54 by a coupling 57 so that water rushing into the resonator pivots the board upwardly and serves to tilt the vanes.
Conversely, water rushing out of the resonator pivots the 15 board downwardly and tilts the vanes to an opposite angle.
In this way, water can be caused to enter the resonator in the direction of arrows 56 and is driven from the resonator in the direction of arrows 58 (Figure 3b). The water rushing in and out of the resonator between the vanes thus 20 exerts a fluctuating force on the ship carrying the vanes and this force can be used to propel the ship. Of course, any suitable number of resonators of different shapes and sizes can be used in this manner.
Instead of using the board 52 and coupling 57, it 25 is possible to use self-orientating vanes 60 as shown in Figures 6a and 6b. ~hese vanes are symmetrical vanes each pivotally moun-ted towards one side on pivots 62 fixed to the mouth of the resonator 26. As the water flows into the resonator mouth 32 in the direction of arrows 64, the vanes 60 automatically rotate in a clockwise direction until further movement is limited by stops, shown diagrammatically at 66. The inclination of the vanes to the horizontal is then 45. On the other hand, as water flows out of the mouth, the vanes 60 rotate in an anti-clockwise direction until they strike schematically illustrated stops 68. The direction of flow of the water 10 longitudinally of the ship is thus reversed automatically by the vanes.
A resonator arrangement similar to that of Figure 2 can also be used to drive a ship or boat, in which case the flow through outlet 40 is guided to a nozzle for 15 driving the ship.
As ocean waves have a fairly wide frequency spectrum but normally have one predominant frequency at which a maximum amount of energy can be extracted, the resonator should suitably be tuned to this predominent 20 frequency. Tuning can be effected by ad~usting the air pressure of the air cushion 36 in the resonators of Figures
THIS INVENTION relates to the utilisation of wave motion, particularly the motion of sea waves.
In the past attempts have been made to utilise energy from the sea. There are three basic ways in which these attempts have been made. Firstly, floats have been used to follow the wave motion and to generate power.
Secondly, sea waves have been used, for example, by generating power as sea water flows over or through a dam.
The third basic method, which has been considered for the 10 purpose of generating a minimal amount of power, is to use sea water to blow air through an orifice in, for example, - a floating buoy to cause a whistling sound.
These prior proposals have only met with limited success and it is an aim of the present invention to 15 provide an improved method and unit for utilising power from the sea.
According to the invention, there is provided a power unit comprising a resonator having a mouth located in the sea and containing a body of water and an air 20 cushion above the body of water; the air cushion being - . ~
: . .
.
:
controlled to cause the water to resonate in response to pressure fluctuations resulting from wave motions in the sea, thereby developing fluctuations of increased pressure, said controlling means comprising a sensor in the resonator and a compressor for providing adjustment of air pressure in the resonator in response to pressur~e sensed by the sensor; and the unit being constructed so that the increased pressure fluctuations create a fluid flow; and means for utilising the fluid flow so created.
The resonator may be a Helmholtz resonator and have a neck defining a relatively small flow area compared with the surface area of the body of water immediately below the cushion.
The means for controlling the air cushion control the pressure of the air forming the air cushion for tuning the resonator to provide a suitable resonance in response to wave motion.
The means for controlling the fluid flow may include an outlet above the neck of the resonator and through which water can be forced, for example, into a pressure tank~ The water from the pressure tank may be fed to a turbine for driving an alternator or generator to generate power. Alternatively, the mouth of the reson~tor may be provided with vanes for directing water flowing from the mouth. This water flow can be used, for example, to propel a boat or ship.
The invention also extends to a method of generating power, which comprises providing a resonator having a mouth located in the sea so that the resonator contains a body of water and an air cushion; said mouth having a small flow area compared with a surface area of said body of water immediately below said air cushion; sensing the pressure in said air cushion; controlling the pressure of the air cushion in response to the pressure sensed in said air cushion; thereby causing the water in the resonator to resonate in response to pressure fluctuations resulting from wave motions in the sea so that fluetuations of inereased pressure are developed; eausing the increased pressure fluetuations to ereate a fluid flow; and utilizing the fluid flow so created to generate power.
The invention further e~tends to an apparatus for use in a power unit, the apparatus having a chamber for reeeiv-ing an air eushion and a body of water below the air eushion and having a mouth for loeating below sea level for plaeing a body of water in the chamber in direct fluid eommunication with the sea; a sensor for sensing pressure in the ~hamber; air eontrol means for increasing or decreasing air pressure in the chamber to create resonant conditions and means for utilising fluid flow created as a result of said resonant conditions.
The apparatus can comprise a pair of resonators Or different heights and arranged substantially side-by-side with sensors in both of the resonators and means for controlling the pressures of air cushions therein for normally maintaining resonant conditions in said resonators.
~' 7~i~
Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
Figure la is a schematic diagram of a resonator having a mouth located below sea level and Figure lb is an - analogous electrical circuit;
Figure 2 is a schematic diagram showing a power unit;
.
Figure 3a is a schematic diagram showing a 1~ propulsion system;
Figure 3b shows an alternative position of part of the system;
Figures 4a, 4b and 4c are provided to illustrate tuning of a resonator;
Figure 5 shows diagrammatically one form of generating station; and Figure 6a and 6b show flow-directing vanes.
As shown in Figure l, an ocean-swell-tuned Helmholtz resonator lO is substantially in the form of an inverted cylinder having a closed upper end and an open lower end providing a mouth 12. The mouth 12 of the resonator is located below sea level and, as shown, the resonator is filled with ater to a variable level 14. An air cushion 16 is formed above the water level 14.
The still water level of the ocean is shown at 18 and a wave is shown at 20, the height of the wave peak being illustrated at 22.
The column of water in the resonator is acted on 10 by the wave motion and, by suitably controlling the pressure of the air cushion 16, it is possible to ensure that the water in the resonator will resonate at the wave frequency.
Thus, it is possible to develop relatively intense pressure fluc.uations in the air cushion and the water below.
In order to determine the characteristics of such a resonator, it is possible to use an analogous electrical circuit as shown in Figure lb. This circuit includes a power generator 24 for generating a voltage which is analo-gous to the ocean wave pressure fluctuations 20; and an inductance L which is analogous to the mass of the water column in the resonator. Capacitance C represents the air cushion 16 above the mass of water and energy lost through radiation of waves from the mouth of the resonator is represented by the energy lost through resistance R. The : ' :
.. .
v~
- `
energy extracted from the resonator for power generation purposes, together wi-th coinciden-tal losses such as viscous drag are represented by resistance Rl.
The power generation unit of Figure 2 is based on the principles illustrated in connection with Figures la and lb. The unit includes a Helmholtz resonator 26 having a primary chamber 28 and a downwardly extending neck 30.
The lower end of the neck 30 defines a mouth 32. The resonator is filled with a body of water up to a movable water level 34 and an air cushion 36 is formed above the body of water. A pressure control system 35 is provided for controlling the pressure of the air defining the air cushion 36 for tuning the resonator. The system 35 has a sensor 35.l mounted in the air cushion 36 and this i9 connected to a control device 35.2 for controlling the operation of a reversible compressor 35.3. The reversible compressor can increase or decrease the pressure in the cushion 36 until resonance is obtained. The resonator is mounted with the neck extending below sea level.
The resonator lO is connected to a pressure tank 38 by an outlet 40 including a non-re-turn valve 42. The valve is designed to allow substan-tially full-bore flow through the outlet 40.
As shown in -the drawing, the tank 38 has an air cushion 44 at its upper end and this is intermittently compressed by flow of water through the outlet 40 into the .
tank and serves to stabilise the flow of water from the pressure tank through an outlet 46 to a turbine 48. The turbine may be any standard water turbine and is connected to drive an alternator 50, another elec-trical generator or any other suitable equipment.
.
A plurality of resonators can be arranged to feed the pressure tank if desired.
When the water in the resonator is subjected to wave motion, the mass of water resonates with the compliance 10 of the air above the water. Intense pressure fluctuations are developed above the neck of the resonator and water is fGrced through the outlet 40 and valve 42 into the tank.
The water leaves the tank through the outlet 46 and then drives the turbine 48.
As shown in Figure 5, a generating station com-prises a floating hull 55 in which a plurality of resonators 26 like that of Figure 2 are mounted. Each of the resonators is arranged with its mouth 32 opening through the bottom of the hull at a location which is permanently below sea 20 level. The resonators are arranged in pairs with outlets 40 of the resonators of each pair communicating with a single pressure tanks 38. The pressure tanks are again arranged to supply water to drive -the turbine 48 and thus the generator 50. The hull 50 can be moved at any suitable 25 location. Naturally, the generating station need not be a floating one.
~ o~
Referring now to Figures 3a and 3b, a resonator 26 which is similar to the resonator of Figure 2 is mounted in a ship or boat (not shown). The parts of this resonator are indicated by the same reference numerals as those used - 5 in Figure 2. The resonator is again provided with a pressure control system for controlling the pressure of the air cushion 36 and the mass of the water in the neck 30 again resonates with the compliance of the air cushion.
A board or similar device 52 is pivotally mounted 10 on the inside wall of the neck at one side of the neck.
This board is connected to a set of streamlined vanes 54 by a coupling 57 so that water rushing into the resonator pivots the board upwardly and serves to tilt the vanes.
Conversely, water rushing out of the resonator pivots the 15 board downwardly and tilts the vanes to an opposite angle.
In this way, water can be caused to enter the resonator in the direction of arrows 56 and is driven from the resonator in the direction of arrows 58 (Figure 3b). The water rushing in and out of the resonator between the vanes thus 20 exerts a fluctuating force on the ship carrying the vanes and this force can be used to propel the ship. Of course, any suitable number of resonators of different shapes and sizes can be used in this manner.
Instead of using the board 52 and coupling 57, it 25 is possible to use self-orientating vanes 60 as shown in Figures 6a and 6b. ~hese vanes are symmetrical vanes each pivotally moun-ted towards one side on pivots 62 fixed to the mouth of the resonator 26. As the water flows into the resonator mouth 32 in the direction of arrows 64, the vanes 60 automatically rotate in a clockwise direction until further movement is limited by stops, shown diagrammatically at 66. The inclination of the vanes to the horizontal is then 45. On the other hand, as water flows out of the mouth, the vanes 60 rotate in an anti-clockwise direction until they strike schematically illustrated stops 68. The direction of flow of the water 10 longitudinally of the ship is thus reversed automatically by the vanes.
A resonator arrangement similar to that of Figure 2 can also be used to drive a ship or boat, in which case the flow through outlet 40 is guided to a nozzle for 15 driving the ship.
As ocean waves have a fairly wide frequency spectrum but normally have one predominant frequency at which a maximum amount of energy can be extracted, the resonator should suitably be tuned to this predominent 20 frequency. Tuning can be effected by ad~usting the air pressure of the air cushion 36 in the resonators of Figures
2 and 3a. Correct tuning is indicated by a maximum pressure fluctuation above the water level, which can be measured by means of sensors 35.l.
In practice, an automatic hill climbing mechanism is desirable in order to keep the resonator tuned to the t~
correct frequency. For this purpose, two resonators 70 of different heights are arranged side by side as shown in Figure 4a. The same air pressure initially exists in both air spaces above the water and the resonant frequencies of both resonators increase with an increase in pressure.
However, there is a difference in resonant frequency as shown in Figure 4b, the lower resonator responding to the higher frequency.
A relatively flat-topped resonance curve, as 10 shown in Figure 4c, can be obtained if the power in the two resonators is added. A maximum amount of power is obtained from the combined system when the peaks for the two resonators in Figure 4b are substantially the same.
The resonators are both connected to an arrange-15 men-t 72 including a reversible compressor 74 for pumping air pressure up or down so that, when the air pressure fluctuations in the air cushion marked A are smaller than those in the air cushion marked B, the compressor is automatically switched by control device-76 to raise the 20 pressure in the cushions A and B until the pressure fluctuations in the two resonators are substantially the same. When the air pressure fluctuations in cushion s are smaller than those in cushion A, the compressor is automatically switched to reduce the pressure in the 25 cushions A and B until the pressure fluctuations in the two resonators become approximately the same. The pressure fluctuations are measured by sensors 78. Thus, the system 6~
is automatically set to absorb the maximum amount of wave energy.
The tuning of the resonators can be taken off the resonant frequency by means of a pressure increase or reduction when reduced power is required. This is particu-larly important when a resonator is used to propel a ship, as described with reference to Figure 3. Of course, a ship being driven by the r:esonator system can be put into reverse by changing the connection 57 between the board 52 and vanes 10 54 to reverse their operation. An auxiliary engine will normally be required for a resonator driven ship.
The resonators described can be used in floating break water units consisting of at least two resonators per unit and a similar hill climbing mechanism to that described 15 with reference to Figure 4a can be used for tuning the resonators. Energy can be dissipated by providing suitable leaks above the throats of the resonators at a connection between the resonators and a pressure tank similar to that of Figure 2.
... . .
'
In practice, an automatic hill climbing mechanism is desirable in order to keep the resonator tuned to the t~
correct frequency. For this purpose, two resonators 70 of different heights are arranged side by side as shown in Figure 4a. The same air pressure initially exists in both air spaces above the water and the resonant frequencies of both resonators increase with an increase in pressure.
However, there is a difference in resonant frequency as shown in Figure 4b, the lower resonator responding to the higher frequency.
A relatively flat-topped resonance curve, as 10 shown in Figure 4c, can be obtained if the power in the two resonators is added. A maximum amount of power is obtained from the combined system when the peaks for the two resonators in Figure 4b are substantially the same.
The resonators are both connected to an arrange-15 men-t 72 including a reversible compressor 74 for pumping air pressure up or down so that, when the air pressure fluctuations in the air cushion marked A are smaller than those in the air cushion marked B, the compressor is automatically switched by control device-76 to raise the 20 pressure in the cushions A and B until the pressure fluctuations in the two resonators are substantially the same. When the air pressure fluctuations in cushion s are smaller than those in cushion A, the compressor is automatically switched to reduce the pressure in the 25 cushions A and B until the pressure fluctuations in the two resonators become approximately the same. The pressure fluctuations are measured by sensors 78. Thus, the system 6~
is automatically set to absorb the maximum amount of wave energy.
The tuning of the resonators can be taken off the resonant frequency by means of a pressure increase or reduction when reduced power is required. This is particu-larly important when a resonator is used to propel a ship, as described with reference to Figure 3. Of course, a ship being driven by the r:esonator system can be put into reverse by changing the connection 57 between the board 52 and vanes 10 54 to reverse their operation. An auxiliary engine will normally be required for a resonator driven ship.
The resonators described can be used in floating break water units consisting of at least two resonators per unit and a similar hill climbing mechanism to that described 15 with reference to Figure 4a can be used for tuning the resonators. Energy can be dissipated by providing suitable leaks above the throats of the resonators at a connection between the resonators and a pressure tank similar to that of Figure 2.
... . .
'
Claims (7)
1. A power unit comprising a resonator having a mouth located in the sea and con-taining a body of water air cushion means above the body of water;
means controlling the air cushion means for causing the water to resonate in response to pressure fluctuations resulting from wave motions in the sea, thereby developing fluctuations of increased pressure; said controlling means comprising a sensor in the resonator and a compressor for providing adjustment of air pressure in the resonator in response to pressure sensed by the sensor;
said unit being constructed so that the increased pres-sure fluctuations create a fluid flow; and means for utilising the fluid flow so created.
means controlling the air cushion means for causing the water to resonate in response to pressure fluctuations resulting from wave motions in the sea, thereby developing fluctuations of increased pressure; said controlling means comprising a sensor in the resonator and a compressor for providing adjustment of air pressure in the resonator in response to pressure sensed by the sensor;
said unit being constructed so that the increased pres-sure fluctuations create a fluid flow; and means for utilising the fluid flow so created.
2. A unit according to claim 1, wherein the resonator has a neck defining a relatively small flow area compared with a surface area of the body of water immediately below the air cushion means.
3. A unit according to claim 1, wherein the means for utilising the fluid flow includes an outlet above the neck of the resonator and through which water can be forced, means for rela-tively stabilising the flow of fluid leaving the resonator through the outlet, and means for generating power by using said fluid flow.
4. A unit according to claim 1, wherein the means for utilising the fluid flow includes means for directing water flow-ing from the mouth of the resonator.
5. A unit according to claim 1, including two reson-ators of different heights and arranged substantially side by side, the resonant frequencies of both resonators and the pressures of the air cushions therein being such that the pressure fluctu-ations in the two resonators are substantially the same,
6. A method of generating power, which comprises pro-viding a resonator having a mouth located in the sea so that the resonator contains a body of water and an air cushion, said mouth having a small flow area compared with a surface area of said body of water immediately below said air cushion; sensing the pressure in said air cushion; controlling the pressure of the air cushion in response to the pressure sensed in said air cushion;
thereby causing the water in the resonator to resonate in response to pressure fluctuations resulting from wave motions in the sea so that fluctuations of increased pressure are developed;
causing the increased pressure fluctuations to create a fluid flow; and utilising the fluid flow so created to generate power.
thereby causing the water in the resonator to resonate in response to pressure fluctuations resulting from wave motions in the sea so that fluctuations of increased pressure are developed;
causing the increased pressure fluctuations to create a fluid flow; and utilising the fluid flow so created to generate power.
7. A method according to claim 6, wherein the pressure of the fluid flow created is relatively stabilised and then fed to a turbine to generate power.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA77/7239 | 1977-12-05 | ||
| ZA00777239A ZA777239B (en) | 1977-12-05 | 1977-12-05 | Utilisation of wave motion |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1106728A true CA1106728A (en) | 1981-08-11 |
Family
ID=25572346
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA317,303A Expired CA1106728A (en) | 1977-12-05 | 1978-12-04 | Utilisation of wave motion |
Country Status (13)
| Country | Link |
|---|---|
| JP (1) | JPS5499843A (en) |
| AU (1) | AU4222378A (en) |
| CA (1) | CA1106728A (en) |
| DE (1) | DE2852952A1 (en) |
| ES (1) | ES476026A1 (en) |
| FR (1) | FR2410747A1 (en) |
| GB (1) | GB2009328B (en) |
| IE (1) | IE47598B1 (en) |
| IS (1) | IS1062B6 (en) |
| NO (1) | NO784024L (en) |
| NZ (1) | NZ189062A (en) |
| PT (1) | PT68867A (en) |
| ZA (1) | ZA777239B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3039030C2 (en) * | 1980-10-16 | 1983-04-21 | Gramer, Allan, 82600 Söderhamn | Device for utilizing part of the energy of water waves, in particular surf waves |
| JPS5979074A (en) * | 1982-10-28 | 1984-05-08 | Suke Ishii | Improvement of engine absorbing exhaust fluid of jet engine, turbine engine and ship |
| GB2245031A (en) * | 1990-06-11 | 1991-12-18 | Denis Joseph Rowan | Wave power resonance generator |
| US7043904B2 (en) * | 2003-12-23 | 2006-05-16 | Edwin Newman | Electrical energy from live loads |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR579587A (en) * | 1923-03-31 | 1924-10-20 | Device for transforming the movement of waves or waves into motive force | |
| FR1049067A (en) * | 1952-01-12 | 1953-12-28 | Electricite De France | Method and device for controlling wave energy |
-
1977
- 1977-12-05 ZA ZA00777239A patent/ZA777239B/en unknown
-
1978
- 1978-11-29 IE IE2362/78A patent/IE47598B1/en unknown
- 1978-11-30 IS IS2467A patent/IS1062B6/en unknown
- 1978-11-30 NZ NZ189062A patent/NZ189062A/en unknown
- 1978-11-30 NO NO784024A patent/NO784024L/en unknown
- 1978-12-01 GB GB7846795A patent/GB2009328B/en not_active Expired
- 1978-12-04 CA CA317,303A patent/CA1106728A/en not_active Expired
- 1978-12-04 PT PT68867A patent/PT68867A/en unknown
- 1978-12-04 FR FR7835132A patent/FR2410747A1/en not_active Withdrawn
- 1978-12-04 ES ES476026A patent/ES476026A1/en not_active Expired
- 1978-12-05 JP JP15047778A patent/JPS5499843A/en active Pending
- 1978-12-05 DE DE19782852952 patent/DE2852952A1/en not_active Withdrawn
- 1978-12-05 AU AU42223/78A patent/AU4222378A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| FR2410747A1 (en) | 1979-06-29 |
| GB2009328B (en) | 1982-04-21 |
| IE782362L (en) | 1979-06-05 |
| NO784024L (en) | 1979-06-06 |
| IS1062B6 (en) | 1981-08-26 |
| IS2467A7 (en) | 1979-06-06 |
| PT68867A (en) | 1979-01-01 |
| ZA777239B (en) | 1979-04-25 |
| ES476026A1 (en) | 1979-06-16 |
| IE47598B1 (en) | 1984-05-02 |
| JPS5499843A (en) | 1979-08-07 |
| AU4222378A (en) | 1979-06-14 |
| DE2852952A1 (en) | 1979-06-07 |
| GB2009328A (en) | 1979-06-13 |
| NZ189062A (en) | 1982-06-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |