JP2017501083A - Ship propulsion unit - Google Patents

Abstract

A marine propulsion unit has a streamlined body. The streamlined body has a front end and a rear end, and in use, the front end faces upstream, the rear end faces downstream, and the front end is larger than the rear end and in the intended movement direction. It has a cross section that is perpendicular to it. A water inlet opening is provided at the front end, the water inlet opening communicates with the impeller, the impeller rotates about an axis parallel to the intended direction of movement, and one or two Has more than one blade. Water entering the water inlet opening is ejected radially away from the rotation axis of the impeller, and the ejected water is ejected from one or more nozzles through the streamlined body. Pushed out along the outer surface.

Description

  The present invention relates to a marine propulsion unit having a streamlined body, which consumes significantly less energy than conventional / normal marine propulsion means.

  As energy resources and environmental issues are on the agenda around the world, new ideas emerge from the process of improving known marine technology. In this refinement process, the source of loss from marine propulsion system components has been under constant interest and analysis for many years. Improvements in composite materials have impacted the development of more efficient marine propulsion technologies.

  This proposed new propulsion system is able to obtain higher overall propulsion efficiency by using a new and different active energy conversion unit that converts mechanical energy to water in combination with a unique passive energy absorption unit Is the purpose.

  There are basically two main propulsion systems or concepts used on a commercial basis. Propulsion by a propeller disposed at the rear end of the ship, and a water jet that discharges a water jet from the rear end of the ship and has a water inlet at other locations below the surface of the hull.

  The key areas of loss in today's marine propulsion systems are propeller vortex loss or angular momentum loss, which can be up to 30%, up to 30% in water jets derived from the jet duct inlet (inlet with an angle to the hull side) And existing existing losses including surface friction or shear wall stress (boundary layer effect) in both systems.

  In this regard, vortex loss is understood as the energy imparted to the water as the propeller agitates the water and creates a volume that rotates angularly around and behind the propeller (angular momentum loss). The volume of water that is agitated includes a large energy loss, and if there is no loss, this energy could be used for propulsion forward.

  Surface friction or shear wall stress is particularly noticeable at the inlet of water jet systems. On wet surfaces, there is a boundary layer close to the surface where the water velocity is zero, and at the same time, the frictional relationship with the surface requires additional energy to overcome surface friction or shear wall stress. The additional energy becomes a further energy use.

  Accordingly, it is an object of the present invention to provide a propulsion system that eliminates the loss of conventional propulsion systems and has further advantages.

  The present invention addresses this object by providing a single marine propulsion unit, the propulsion unit having a streamlined body, the streamlined body having a front end and a rear end. In this case, the front end portion is directed upstream, the rear end portion is directed downstream, the front end portion is larger than the rear end portion and has a cross section perpendicular to the intended moving direction, and the water inlet opening is Provided at or adjacent to the front end, the water inlet opening communicates with the impeller, which rotates about an axis parallel to the intended direction of movement and is one or two Water that has two or more blades and enters the water inlet opening is ejected radially away from the rotation axis of the impeller, and the ejected water is ejected from one or more nozzles The extruded water is pushed out to be directed along the outer surface of the streamlined body.

  When the jetted water is pushed out of one or more nozzles, preferably the rectifying nozzle directs the tangential component of the jetted water, preferably radially, with respect to the axis around which the impeller rotates. Further, the effect is remarkable by directing along the outer surface of the streamlined body and changing the flow direction in the axial direction toward the rear end of the streamlined body depending on the curvature of the streamlined body.

  As used herein, the term “rectifying nozzle” should be understood as a nozzle that directs and controls the water extruded from the commutating nozzle in a predetermined and well-defined direction / flow.

  The background of the new marine propulsion unit concept of the present invention is the fact that the latest impellers in pump technology when tested alone achieve an efficiency better than 90%, which is low in the streamlined body When combined with the overall drag coefficient, it provides a much more efficient driving force than prior art devices.

  Each component of the new propulsion system has a separate and very low friction loss, which in combination achieves less loss and thus achieves greater overall propulsion efficiency.

  The new propulsion system preferably has a rotating streamlined body, ideally at an angle of attack of zero, and is also referred to herein as a “pod (POD)”, meaning the entire system.

  The thrust from the propulsion system comes from the water that interacts with the propulsion system. Due to the relative momentum change of the water driven by the impeller and passing through the propulsion system, the dynamic mechanism accelerates the water, and the nozzle causes the water to flow alongside the streamlined body (again, The flow direction of the tangential component (with respect to the rotation axis of the impeller) is changed in the radial direction, and the flow direction is changed in the axial direction according to the curvature of the surface of the pod so as to be directed toward the rear end of the streamlined body.

  At least in this document, “ideally a streamlined rotator with zero angle of attack” should be understood as a symmetrical body designed to approximate the theoretical definition, Insignificant changes are allowed to allow the body to be used for practical applications. For example, the body has one or more struts / beams that attach the body to the vessel and transmit propulsion to the vessel.

  Thus, the impeller acts as a pump, which pumps water from the area in front of the pod, accelerates the water, and provides water in a controlled manner by providing one or more nozzles. Squirt along the curved outer surface of the pod.

  When the impeller rotates, the impeller generates a negative pressure, whereby water is sucked into the impeller, and water is accelerated by the rotational force of the impeller and ejected along the periphery of the impeller. In this position, one or more rectifying nozzles are arranged to substantially surround the impeller. The rectifying nozzle is used to change the direction of the tangential component of the jetted water flow to a radial direction and then direct the accelerated water along the pod body, depending on the curvature of the surface of the pod, The main body is propelled in the opposite direction while changing the flow direction in the axial direction and backward flow. In an embodiment of the invention in which only one rectifying nozzle is provided, this nozzle may cover part of the circumference of the impeller or substantially on the surface of the pod covering the entire circumference of the impeller. A substantially uniform flow of water that is evenly distributed may be generated. If multiple nozzles are provided, the nozzles may be individually adjusted so that the accelerated water flowing over the surface of the pod has different layer thicknesses, velocities and kinetic energy quantities, As a result, the variation in the momentum of the water flow along the pod body may vary so that the pod can be steered.

  In other embodiments, if the curvature itself at the beginning of the surface of the body has a uniform and smooth curvature that changes the flow from radial to axial, the outer portion of the commutation nozzle can be reduced or eliminated. Good.

  The nozzle may also be directed to provide reverse propulsion, thereby preventing the advancement of the pod and the vessel to which the pod is attached.

  Also, the water flow direction may be optimized so that the nozzle is directed to fine tune the tangential flow component and the water is directed to the nozzle in the direction toward the rear of the streamlined body.

  To generate a substantially uniform thrust from the pod for smooth operation, the thrust generated by the change in the direction of water flow across the surface of the pod will be substantially uniform across the pod surface. The pod should have a symmetrical structure.

  In yet another advantageous embodiment of the invention, the overall cross section in the longitudinal plane of the streamlined body has a droplet shape and the trailing end tapers towards the apex.

  This configuration provides the pod with the important aspect that water flowing across the pod body has optimal energy consumption and, as a result, maximum thrust. In particular, having a tapered trailing end minimizes the tendency to create turbulence, in which case the kinetic energy stored in the flow is reduced from the impeller rotation along the pod surface from the pod taper. (Rear) Efficiently converted to end thrust.

  The pod naturally also has means for attaching the propulsion unit to the ship, such means being suitable for transmitting thrust (propulsion) to the ship. The attachment means must be of a nature that allows the force generated by the pod to be transmitted and at the same time design the attachment means to minimize flow resistance so as to minimize energy loss It would be advantageous.

  For these purposes, in some embodiments, it may be necessary to deviate the pod from the symmetrical structure to compensate for the effects of the means for attaching the propulsion unit to the vessel. A complete design combining the attachment means (ie struts and / or beams) and the pod itself is inevitably implemented to minimize the generation of turbulence around the pod or between the pod and the vessel.

  In another advantageous embodiment of the invention, the water inlet opening, the impeller and one or more nozzles are arranged on the surface of the streamlined body so that the water ejected from the nozzle is streamed It is guided (directly) along the outer surface of the.

  By arranging the inlet opening and the impeller on the surface of the streamlined body, it is achieved that the upstream water is not disturbed before it hits the impeller. At the same time, the water spouted from the impeller through the nozzle is directed directly to the surface of the streamlined body, whereas in other embodiments where the impeller is located in a relatively protected position, The protective structure can cause turbulence in both the flow of water as it enters the impeller and the flow of water that exits the impeller.

  When the impeller is not arranged so that the accelerated water is jetted directly along the surface of the pod, the surface from the nozzle to the surface of the pod is hydraulically correct, i.e. the layer Designed to ensure flow.

  In another advantageous embodiment of the invention, the nozzle has a circular shape arranged around the impeller on the surface of the streamlined body and the nozzle is separated into sections.

  The nozzle is used to control and direct water exiting the impeller, for example directing accelerated water along the streamlined body. By dividing the nozzle into separate sections and allowing the geometry of each section to be controlled, it is possible to control the flow of water along the streamlined body, Control the propulsion of water along various parts and improve the control of ships with attached pods.

  Furthermore, in a very important embodiment, all the blades arranged on the impeller are arranged at a radial distance from the center of rotation of the impeller, leaving the central area of the impeller as a bladeless surface, The surface has a surface substantially perpendicular to the rotational axis of the impeller. The vaneless surface may be conically shaped to indicate the direction of travel or may have other suitable contours.

  By providing an open part in the center of the impeller, the impeller does not cause any vortex or turbulence, in this case there is no energy loss of water entering the impeller, to supply power to the impeller It provides the impeller with a better ratio between the energy used for and the energy transferred to the water away from the impeller. Compared to conventional ship screws, the fact that the screw is usually placed on the shaft in front of the screw, and the angular momentum loss (loss close to the shaft) before the water reaches the blades of the screw to give propulsion energy There is considerable energy loss in the screw propeller due to the fact that typically half of the loss at the tip of the blade of the screw, and the loss due to the volume of water drawn by the propeller around the propeller) .

  By placing an open surface in the center of the impeller, the angular momentum loss is eliminated or at least greatly reduced.

  The present invention is also directed to a method of providing propulsive force, which includes placing the propulsion unit described above in a lower water surface portion of a ship, allowing water to flow into the inlet opening of the propulsion unit, and allowing water to enter the rotating impeller. By accelerating the water when it comes into contact with the arranged vanes, the water ejected from the impeller is ejected from the nozzle along the surface of the propulsion unit, and the accelerated water at the front of the propulsion unit is The water accelerated along the rear of the propulsion unit provides thrust and provides propulsion.

  The advantages achieved by installing the propulsion unit are the same as those described above.

  This embodiment is preferred as a high speed propulsion system, since the risk of damaging cavitation in the propulsion system is minimized when the speed of the ship and the propulsion unit is increased, the onset of cavitation is controllable and greater output If is added, a higher ship speed can be obtained.

  In this connection, another advantageous embodiment of the invention is also important, in which the blades arranged in the impeller can be redirected or adjusted with respect to the radial direction. By being able to adjust the impeller blades, the optimum angle of attack between the water flow and the blades should be achieved at any combination of impeller speed, i.e. rotational speed, underwater vessel speed, etc. Can do.

  Hereinafter, the present invention will be described with reference to the accompanying drawings.

1 shows a marine propulsion unit according to an embodiment of the present invention. The water inlet opening 13 where the impeller is located is shown. 3 illustrates an embodiment in which a plurality of nozzles are disposed within a nozzle member. Figure 3 shows a computer simulation of a conventional screw attached to a shaft that causes rotation. A propulsion unit moving in the water. An embodiment in which dimples are provided on the surface of the main body and the drive shaft extends in the moving direction is shown.

  FIG. 1 shows a marine propulsion unit 1 according to an embodiment of the invention. The propulsion unit 1 has a streamlined body 10, which has a front end 11 and a rear end 12. In use, the front end 11 is directed upstream, i.e. arranged in the direction of movement of the ship to which the propulsion unit is attached. The front end portion 11 has a cross section that is larger than the rear end portion 12 and perpendicular to the moving direction.

  Further, the front end portion 11 is provided with a water inlet opening 13 in which an impeller as shown in FIG. 2 is arranged. The impeller rotates about the axis 14, thereby accelerating the water entering through the inlet opening 13 and at the same time changes the direction of water flow to a substantially radial direction with respect to the axis of rotation. When the marine propulsion unit 1 attached to the ship moves in the water, the water flow velocity along the axis 14 in front of the pod is the same as the speed of the ship moving in the water. Water is accelerated by the rotation of the impeller and ejected from the impeller at a fairly high speed. The accelerated water is forced out of one or more rectifying nozzles 15 and is thereby directed along the outer surface of the streamlined body 10.

  In the embodiment shown in connection with FIG. 1, one or more rectifying nozzles 15 are disposed within the nozzle member 16 as shown in FIG. 3. In the embodiment shown in FIGS. 1 and 3, the rectifying nozzle 15 is arranged over the entire circumference of the impeller, but depending on the desired flow of water along the main body 10 of the marine propulsion unit 1, any nozzle Designs and combinations can be used.

  FIG. 2 shows an overview of the impeller 17. In this embodiment, the impeller includes a disk 18 arranged to rotate about a center 19, and the impeller 17 receives water from the direction indicated by arrow 20 and is substantially in the direction indicated by arrow 21. Ejected in equal amounts, i.e. having a combination of radial and tangential components, preferably distributed radially and evenly from the disk 18 (although arrow 21 shows only two directions, It is clear that accelerated water is ejected radially over the entire circumference of the disk 18). The water is accelerated by the rotation of the impeller, and the water released from the impeller in the direction of the arrow 21 has a higher kinetic energy level than the water 20 entering the impeller 17.

  The impeller 17 includes blades 22 arranged at a desired spacing along the impeller surface in a substantially radial orientation. The wing design is curved in this embodiment, but may be designed as a straight and flat wing. Typically, the vanes are slightly angled with respect to the radial direction 23. Further, it is preferable that the direction of the blades can be adjusted / finely adjusted according to a desired thrust, the rotational speed of the impeller, the speed of the ship, and the like. Thus, the angle of attack of the blade relative to the water (ie, how much the blade is rotating relative to the radial direction) can be adjusted by simply rotating the orientation of the entire blade or a portion of the blade.

  In this embodiment, the impeller has vanes that are arranged at a distance from the center 19 of the disk 18 so as to leave the central region substantially open and unobstructed. This means that the water entering through the inlet opening 13 is not substantially disturbed until it engages the disk 18 as shown in FIG. Important in terms. As described below with reference to FIG. 4, in the prior art, swirl loss occurs when the blade immediately engages water, for example by starting to move directly from the center of the disk. This will generate a certain amount of inlet vortex that reduces the effectiveness of the impeller.

  FIG. 4 shows a computer simulation of a conventional screw 30 which is attached to a rotating shaft 31 and thereby generates propulsion in a traditional manner on a ship. The rotation of the screw causes a number of swirls that indicate turbulent water flow. At the axial center, a hub swirl loss occurs due to the rotation of the shaft 31 and the generation of the swirl flow 32 caused by the innermost part of the blade of the propeller 30 that rotates about the shaft, and the shaft is propelled. Does not contribute to power.

  Furthermore, the single blade 33 of the propeller 30 has a distal end, where a tip loss 34 occurs, which also only disturbs the water without contributing to propulsion, Turbulence 34 is generated at the distal end of each propeller blade 33. These turbulent flows 34 do not contribute to the propulsion force of the propeller device.

  In addition, when water is accelerated by the screw, it is most accelerated mainly in the axial direction, but some is accelerated in the angular direction and vortex loss increases, thereby contributing to the above loss. The total amount of loss reaches up to 30% of the kinetic energy imparted to water by torque.

  Ship designers have found that the optimal relationship between the number of blades, the area of the blades and the above losses so that optimum energy utilization and maximum propulsion per unit energy is achieved as a traditional propeller solution. You will inevitably end up with sex. However, in the present invention, neither vortex loss 32 nor turbulent loss 34 occurs.

  As shown in FIG. 5, when the propulsion unit 1 moves through the water at a predetermined speed, the water flows into and out of the impeller and the rectifying nozzle and flows along the propulsion unit body 10.

  Due to the rotation of the impeller 17 (see FIG. 2), water is sucked into the tip 11 of the propulsion unit 1. This suction is indicated by streamline 41. Due to the rotation of the impeller and the pumping action of the blades 22 (see FIG. 2), water is ejected substantially perpendicular to the inflow direction 41, so that the water passes through the rectifying nozzle 15 and the propulsion unit 1. Is ejected along the surface 10 of Due to the Coanda effect, the accelerated water 42 follows a curved surface. The Coanda effect is a long-recognized phenomenon, in which a fluid jet such as air or water sticks to and follows a curved surface along a curved path, does not flow linearly, The jet does not leave the curved surface. Neglecting the friction between the fluid and the surface along which the fluid flows, in this case the friction between the water and the outer surface 10 of the propulsion unit 1, the only force acting on the fluid particles is due to pressure. Thus, creating a pressure difference between the inside and outside of the accelerated water layer 42, the outside pressure being greater than the inside pressure.

  There is a pressure gradient across the flow 42 so that there is a negative pressure in the vicinity of the surface 10 that keeps the flow along the surface of the propulsion unit.

  Therefore, thrust is generated when the accelerated water 42 flows along the surface 10 of the marine propulsion unit 1 and the pressurized water leaves the rear end (tapered end) 12 of the marine propulsion unit 1. Thus, thrust is generated and the impeller accelerates the water, that is, imparts kinetic energy to the water, causing a change in the momentum of the water flow 42 along the surface 10 of the marine propulsion unit 1, The thrust 43 which provides propulsive force to the propulsion unit 1 for use and the ship attached thereto is caused.

  Depending on the speed of the marine vessel and therefore the marine propulsion unit in the water, and depending on the curvature of the propulsion unit 1 and the density of the water (which varies with temperature and salinity content), the rectifying nozzle opening 15 Are designed as appropriate or can be adjusted to change the flow pattern of the pressurized water 42 across the surface 10 of the propulsion unit. It is possible to propel the propulsion unit 1 in different directions by changing the thickness or speed of the flow of water 42 to which kinetic energy is applied, and the resulting change in thrust, thus It is possible to steer the ship in a desired direction.

  In the embodiment described with reference to the drawings, the impeller is arranged substantially on the surface 10 of the marine propulsion unit 1, but in other embodiments the impeller and optionally the rectifying nozzle are The inlet opening 13 is arranged below the surface in the cavity in front of the propulsion unit 1 so as to communicate with the impeller, whereby the impeller communicates water smoothly with the outer surface 10 of the marine propulsion unit 1. Water is ejected from the rectifying nozzle along the surface. Depending on the speed of the marine vessel and therefore the marine propulsion unit 1, the increase in the ambient pressure of the water in contact with the impeller and the rectifying nozzle under the surface of the water Delays the start of cavitation in the thrust generator. This embodiment is preferred for high speed propulsion systems, the start of cavitation is controllable and adds greater power as the speed of the ship and propulsion unit increases and the risk of damage to the cavitation of the propulsion system decreases. By doing so, a higher vessel speed can be obtained.

  In FIG. 6, the surface 10 has dimples (small recesses) 48, and as described above, the boundary layer is formed outside the propulsion unit while the propulsion unit is moving in the water. Prevents growth, thereby maintaining a pressure gradient from stream 42 and making negative pressure more pronounced. Instead of dimples, a small notch (ie a bulge into the body of the propulsion unit), a bulge (a bulge out of the surface (plane) of the propulsion unit), or “shark skin” (especially for high speed ships) A well-known wet surface finish) may be provided to achieve the same purpose of inhibiting the boundary layer from growing.

  A drive shaft 44 extending in the moving direction of the pod is also shown in FIG. This drive shaft is similar to a conventional propeller shaft, and when the pod according to the present invention is mounted, it is not necessary to change the mounting and arrangement of the conventional marine motor inside the hull of the marine vessel.

  The pod further has attachment means in the form of attachment beams or struts 46. This attachment beam 46 is used to attach the pod to the vessel, support the pod, and transfer at least a portion of the thrust from the pod to the vessel.

  In order to be able to compare the present invention with conventional ship propellers and water jets, a well-established and accepted computational model is “Principles of Naval Architecture, Second revision Vol. II, 1988”, in particular, 132-135, 225-227, which is incorporated herein by reference. A few assumptions and fits are needed in the calculation. According to theory, as summarized in the following table, using the present invention results in significantly better energy usage than conventional methods. For computational purposes, the present invention is compared with the propeller used in the latest series of Triple E container carriers such as handed over to Maerskline. These propellers are considered to have the highest (energy) efficiency among the propellers designed and used so far.

  “HBI” means the present invention.

  The table above shows a comparative calculation between the present invention and the propellers used in Maersk lines triple E series container carriers. Each column represents a different entrance area.

  The results from the last row show that the entrance area of 31.42 square meters gives a relatively large thrust with relatively little energy consumption. The larger the inlet area, the better the results.

Claims (15)

A propulsion unit for a ship,
A streamlined body, the streamlined body has a front end and a rear end; in use, the front end is directed upstream, the rear end is directed downstream, and the front end is Having a cross-section that is larger than the rear end and perpendicular to the intended direction of travel,
A water inlet opening is provided at or adjacent to the front end, the water inlet opening communicates with an impeller, and the impeller is parallel to the intended direction of movement. Rotating around an axis, having one or more vanes,
The water that enters the water inlet opening is ejected in a direction away from the rotation axis of the impeller in a radial direction, and the ejected water is the water ejected from the one or more nozzles. A propulsion unit that is pushed out along the outer surface of the streamlined body.   The propulsion unit according to claim 1, wherein the streamlined body is a rotating body at an angle of attack of zero, and is symmetric with respect to the rotation axis of the impeller.   The propulsion unit according to claim 1 or 2, wherein an overall cross section of the streamlined body in a longitudinal plane has a droplet shape and the trailing end is tapered.   The propulsion unit according to any one of claims 1 to 3, wherein the streamlined body has means for attaching the propulsion unit to a ship, the means being suitable for transmitting thrust to the ship.   The propulsion unit according to claim 4, wherein the means is a propeller shaft of a ship, and the propulsion unit is mounted instead of a propeller, and the propeller shaft rotates an impeller of the propulsion unit.   The propulsion unit according to any one of claims 1 to 4, wherein motor means for rotating the shaft of the impeller is provided inside the streamlined body.   The water inlet opening, the impeller, and the one or more nozzles are arranged so that water ejected from the nozzle is directed along an outer surface of the streamlined body. The propulsion unit according to claim 1, wherein the propulsion unit is disposed on a surface of the propulsion unit.   The propulsion unit according to any one of claims 1 to 7, wherein the nozzle has a circular shape and is arranged around the impeller and on the surface of the streamlined body and separated into sections.   All blades disposed on the impeller are spaced apart from the impeller rotational axis by a radial distance, leaving the central region of the impeller as an open bladeless surface, the bladeless surface being The propulsion unit according to any one of claims 1 to 8, wherein the propulsion unit has a surface substantially perpendicular to the rotation axis of the impeller.   The one or more blades are disposed substantially radially of the impeller, are curved relative to the radial direction through the blade, and eject water from the impeller substantially radially. A propulsion unit according to claim 1 or 9.   The propulsion unit according to claim 1 or 10, wherein the vanes arranged in the impeller can be turned or adjusted with respect to a radial direction.   The nozzle includes a rectifying unit having a plurality of walls and a lid shape, and the wall and the lid are controlled with respect to a flow of water, and the rectifying unit is configured to rotate the ejected water along an axis of rotation of the impeller. The propulsion unit of claim 1, wherein the propulsion unit is directed along a surface of the streamlined body with a radial orientation relative to the surface.   The propulsion unit according to any one of claims 1 to 12, wherein a plurality of dimples, a plurality of notches, and / or a plurality of ledges are provided on at least a part of the surface area of the streamlined body. A method of providing propulsion,
The propulsion unit according to any one of claims 1 to 13 is arranged in a lower surface portion of a ship,
Let water flow into the water inlet opening of the propulsion unit,
Accelerating the water when it comes into contact with the blades arranged on the impeller,
The water ejected from the impeller is ejected from the nozzle along the surface of the propulsion unit,
The water accelerated at the front end of the propulsion unit generates a negative pressure,
Providing a propulsive thrust by water along the rear of the propulsion unit. A method of providing propulsion,
The propulsion unit according to any one of claims 1 to 13 is disposed in a lower surface portion or a lower surface cavity of a front end of the pod,
Increase the speed of the ship, and therefore the speed of the propulsion unit, the ambient pressure of the water in contact with the impeller and the rectifying nozzle below the surface of the water,
A method of delaying the onset of cavitation in the thrust generation section of the overall propulsion system due to relative flow rates associated with local pressure.