CN103168168A - Oscillating hydrofoil, turbine, propulsive system and method for transmitting energy - Google Patents

Abstract

System and method for converting kinetic energy from a fluid flow into mechanical energy, the method comprising the steps of: a) providing a turbine including first and second hydrofoils, each of the hydrofoils being able to move linearly in a heaving motion, and being able to oscillate about a spanwise axis in a pitching motion, said heaving and pitching motions being quasi-sinusoidal, b) coupling the heaving motions of the first and second hydrofoils to the pitching motions of the second and first hydrofoils respectively, with the pitch-heave motion phase being substantially equal to the inter-hydrofoil phase, the heaving motion of one of the hydrofoils thereby driving the pitching motion of the other hydrofoil; and c) transforming the heaving motions of the hydrofoils into a rotational movement of a rotatable shaft, with linear-to-rotary transmission means.

Description

Oscillating hydrofoil, turbine, propulsion system and method for transferring energy

technical field

The present invention relates to the field of turbomachines, and more particularly to turbomachines with oscillating foils.

Background of the invention

The prospect of harvesting energy from water flow with hydrodynamic turbines is becoming more attractive than ever in renewable forms of energy because of the high density of flowing water (predictable tidal and river applications) and minimal environmental and human impact.

Applicants are known to have the following publications and patent documents:

[1] The European Marine Energy Center Ltd (EMEC), (2010): http://www.emec.org.uk/tidal_devices.asp

[2]Bernitsas, M., Raghavan, K., Ben-Simon, Y., and E.M.H., G., (2008). VIVACE (Vortex Induced Vibration Aquatic Clean Energy): Anew concept in the generation of clean and renewable energy from fluidflow. ASME Journal of Offshore Mechanics and Arctic Engineering, 130(4), November, p.041101.

[3]Bernitsas, M., Ben-Simon, Y., Raghavan, K., and E.M.H., G., (2009). The VIVACE Converter: Model tests at high damping and Reynolds number around 105. ASME Journal of Offshore Mechanics and Arctic Engineering , 131(1), February, p.011102.

[4] Jones, K., Lindsey, K., and Platzer, M. (2003). An investigation of the fluid-structure interaction in an oscillating wing micro-hydropower generator. Fluid Structure Interaction II, Chakrabarti, Brebbia, Almorza, and Gonzalez -Palma, eds. WIT Press, Southampton, UK, pp.73-82.

[5] Kinsey, T. and Dumas, G. (2010).Testing and Analysis of an Oscillating Hydrofoils Turbine Concept. ASME20103rd JointUS-European Fluids Engineering Summer Meeting, PaperFEDSMICNMM2010-30869, Mohtreal, Canada

[6] Kinsey, T. and Dumas, G. (2008). Parametric Study of an Oscillating Airfoil in a Power-Extraction Regime. AIAA Journal, 46(6), pp.1318-1330

[7] McKinney, W. and DeLaurier, J. (1981). The Wingmill: An Oscillating-Wing Windmill. Journal of Energy, Vol.5, No.2, pp.109-115

[8] Pulse Tidal Limited, (2010): http://www.pulsegeneration.co.uk.

[9] The Engineering Business Limited, (2002). Research and development of a150kw tidal stream generator. Tech. rep., CrownCopyright.

[10]The Engineering Business Limited, (2003). Stingray tidalenergy device-phase2.Tech.rep., The Engineering Business Limited.

[11] The Engineering Business Limited, (2005). Stingray tidal energy device-phase 3. Tech. rep., Crown Copyright.

[12]Anderson, J.M.et al., (1998). Oscillating Foils of High Propulsive Efficiency. Journal of Fluid Mechanics, Vol.360, Apr.1998, pp.41-72. doi: 10.1017/S0022112097008392

[13]Dumas, G.(2010).HAO-Laval: Le project d′hydrolienne à ailesoscillantes.Journal de I′AQME, septembre2010, Vol.25(3), pp.8-10.

[14] Kinsey, T., Dumas, G., Lalande, G., Ruel, J., Mehut, A., Viarouge, P., Lemay, J. and Jean, Y. (2011). Prototype Testing of a Hydrokinetic Turbine Based on Oscillating Hydrofoils. Renewable Energy, 36(6), pp.1710-1718.

The applicant is also known to have these related patents:

US7,493,759B2, February 2009, Bernitsas et al. (VIVACE); WO2004110859A1, June 2004, Lambert-Bolduc WO2005108781A1, May 2005, Paish (Pulse Tidal); US20060275109A1, December 2006, Paish (Pulse Tidal); WO2008053167A1, May 2008, Paish (Pulse Tidal); WO2010015821A2, February 2010, Paish (Paidal) ; WO2008144938A1, May 2008, Dumas et al. (U. Laval); US6,273,680B1, August 2001, Arnold; and US6,323,563B1, November 2001, Kallenberg.

Referring to Figure 1, the use of rectangular oscillating lift surfaces 10a, 10b (referred to as hydrofoils) is advantageous and has been shown to be effective for rotary blade turbines, especially when compared to horizontal axis rotor blades 12, such as state-of-the-art Blades used in wind turbines where the pitching and heaving motion of the hydrofoil is perpendicular to the flow.

When encountering a fluid flow, the oscillating foils perform a combined sinusoidal, quasi-sinusoidal ups and downs motion. It is known that the efficiency of turbines is improved when heave or horizontal motion induces pitch or angular motion.

Referring to Figures 2A to 2C, an embodiment of a hydrodynamic turbine 14 based on an oscillating hydrofoil 10 is shown. The cyclic heave motion of a pair of series-connected foils 10 is converted and transmitted to the rotating shaft 16 by means of a long aluminum rod 18a connected to the crankshaft 20a. By utilizing a chain and sprockets driven by an additional set of rods 18b and crankshaft 20b connected to the axis of rotation 16, the pitch motion of the foils 10 is coupled to their heave motion as a degree of freedom system.

Although functional, this implementation has some disadvantages. One of the disadvantages is the use of elongated rods 18a, 18b that swing into the flowing water, which causes energy loss. Another disadvantage is that the hydraulic force on the rod creates vibrations which promote premature wear of the bearings. In addition, the phase difference between the oscillating movements of the two hydrofoils is 180°. This means they hit zero production points at the top and bottom positions, resulting in undesirable fluctuating power output.

Therefore, there exists a need to transfer energy from a fluid flow with increased efficiency. It would also be desirable to provide a transmission system and method that limits mechanical losses, improves robustness and wear resistance, and flattens the output power curve.

Summary of the invention

It is an object of the present invention to provide a turbine, a propulsion system, a method or a hydrofoil addressing at least one of the above mentioned needs.

According to a first aspect of the invention there is provided a turbomachine. Turbines are used to convert kinetic energy from fluid flow to mechanical energy by driving a rotating shaft.

The turbine includes a support structure, first and second hydrofoils, a heave-pitch assembly and a linear-rotary transmission system.

The first hydrofoil and the second hydrofoil extend from a supporting structure, each hydrofoil is slidably and rotatably connected to the structure to allow each hydrofoil to move linearly in a heaving motion and orbit in a pitching motion. Axis swing in the spanwise direction.

the heave and pitch motions are quasi-sinusoidal, wherein for a given one of the hydrofoils, the heave and pitch motions are out of phase due to the pitch-heave motion phase, and wherein the respective heave motions of the first hydrofoil and the second hydrofoil are due to the water The phase between the wings is out of phase.

The heave-pitch assembly is used to couple the heave motion of the first hydrofoil and the second hydrofoil to the pitch motion of the second hydrofoil and the first hydrofoil respectively, the pitch-heave phase is substantially equal to the inter-hydrofoil phase, and the hydrofoil The heave motion of one of the wings drives the pitch motion of the other hydrofoil.

A linear-rotary transmission system is operatively connected to the first hydrofoil and the second hydrofoil and to the axis of rotation. Thus, the heave motion of the first hydrofoil and the second hydrofoil drives the rotational motion of the shaft.

According to another aspect of the invention, a method for converting kinetic energy from a fluid flow to mechanical energy is provided. The method comprises the steps of:

a) There is provided a turbine comprising a first hydrofoil and a second hydrofoil, each hydrofoil being movable linearly in a heave motion and oscillating about a spanwise axis in a pitch motion. Heave and pitch motions are quasi-sinusoidal, where:

- for a given one of the hydrofoils, the heave and pitch motions are out of phase due to the pitch-heave motion phase, and

- the respective heave motions of the first hydrofoil and the second hydrofoil are out of phase due to the phase between the hydrofoils;

b) coupling the heave motion of the first hydrofoil and the second hydrofoil to the pitch motion of the second hydrofoil and the first hydrofoil respectively, wherein the pitch-heave motion phase is substantially equal to the inter-foil phase, therefore, the hydrofoil The ups and downs of one of the foils drive the pitching motion of the other; and

c) Using a linear-rotary transmission device to convert the ups and downs of the hydrofoil into the rotational movement of the rotary shaft.

According to yet another aspect of the invention, a propulsion system for transferring mechanical energy from a rotating drive shaft is provided. The system includes a support structure, a first hydrofoil and a second hydrofoil, a heave-pitch assembly and a rotary-linear transmission system.

The first hydrofoil and the second hydrofoil extend from a supporting structure, each hydrofoil is slidably and rotatably connected to the structure to allow each hydrofoil to move linearly in a heaving motion and orbit in a pitching motion. Axis swing in the spanwise direction. The heave and pitch motions are out of phase due to the pitch-heave motion phase, and the respective heave motions of the first hydrofoil and the second hydrofoil are out of phase due to the inter-hydrofoil phase.

The heave-pitch assembly is used to couple the heave motion of the first hydrofoil and the second hydrofoil to the pitch motion of the second hydrofoil and the first hydrofoil, respectively. The pitch-heave motion phase is substantially equal to the inter-foil phase, with the heave motion of one of the foils thereby driving the pitch motion of the other hydrofoil.

A rotary-linear transmission system is operatively connected to the rotary shaft and to the first hydrofoil and the second hydrofoil, the rotational motion of the drive shaft thereby driving the heave and pitch motion of the hydrofoil.

Yet another aspect of the invention relates to a hydrofoil. The hydrofoil comprises a pair of parallel extending foils connected via rigid links.

Other features and advantages of the present invention will be more easily understood by reading its preferred embodiments with reference to the accompanying drawings.

Brief description of the drawings

Figure 1 is a schematic diagram of two oscillating hydrofoils and a turbine with horizontal axis rotor blades (prior art).

Figures 2A, 2B and 2C are side perspective views (prior art) of a turbine shown in three different positions, respectively.

Figure 3 is a side perspective view of a turbine according to a preferred embodiment of the present invention.

Figure 4 is a side perspective view of a turbine according to another preferred embodiment of the present invention.

Figure 5 is a side perspective view of a turbine according to yet another preferred embodiment of the present invention. Figure 5A is a front view of the hydrofoil of Figure 5 according to an embodiment of the present invention. FIG. 5B is a side view of the hydrofoil of FIG. 5 .

Figure 6A is a schematic diagram of a heave-pitch assembly incorporating hydrofoils. Figure 6B is a graph showing the pitch and heave motion of the hydrofoil of Figure 6A.

FIG. 7 is a schematic illustration of portions of the heave-pitch assembly of FIG. 6A . Figure 7A is a schematic illustration of a hydrofoil and its corresponding rotary actuator. FIG. 7B is an alternative embodiment of the rotary actuator of FIG. 7 .

Figure 8 is a schematic illustration of a portion of a heave-pitch assembly according to another preferred embodiment. FIG. 8A is an alternate embodiment of the rotary actuator of FIG. 8 .

Figure 9 is a schematic diagram of a portion of a linear-rotary transport system according to a preferred embodiment. 9A and 9B are schematic diagrams of another portion of a linear-rotary transport system according to two preferred embodiments.

Figure 10 is a schematic diagram of components of a linear-rotary transport system according to another preferred embodiment.

Figure 11 is a side perspective view of a turbine according to a preferred embodiment of the present invention. FIG. 11A is a schematic illustration of components of the turbine of FIG. 11 .

Figure 12 is a side perspective view of a turbine according to another preferred embodiment of the present invention. 12A is a schematic illustration of components of the turbine of FIG. 12 .

Figure 13 is a side perspective view of a turbine according to yet another preferred embodiment of the present invention. 13A and 13B are schematic diagrams of alternative embodiments of a rotary actuator.

Figure 14 is a schematic diagram of a propulsion system according to another preferred embodiment of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the following description, similar features in the figures have been given similar reference numerals. To maintain clarity, some elements have not been labeled in some figures where they were labeled in previous figures.

Referring to Figure 3, there is shown a first embodiment of a turbine 30 for converting kinetic energy from a fluid flow (indicated by arrow 32) to mechanical energy. Mechanical energy can be used to drive a rotating shaft from, for example, a generator. The fluid may be of any type, such as air or water, but the fluid flow is preferably a sea or river current.

The turbine 30 includes a first hydrofoil 34a and a second hydrofoil 36a' extending from a supporting structure, in this case a column 38, which is preferably in an upright vertical orientation. Hydrofoils 34a, 36b extend from one side of the column and are generally parallel to each other. Preferably, when the support structure 38 is a single column, another pair of first hydrofoil 34b and second hydrofoil 36b extends on opposite sides of the column, such as to maximize the lifting surface of the turbine 30 . Although a shallower configuration can be achieved when the column is in an upright or vertical orientation, the column can also be positioned in a horizontal orientation, with the hydrofoil extending in the vertical direction. The hydrofoils 34, 36 have elongated and generally planar bodies. Each hydrofoil 34, 36 also has an extended curved profile. They also have a symmetrical cross-section.

Referring now to FIG. 4 , a second embodiment of a turbine 30 is shown. In this case the support structure comprises two spaced columns 38a, 38b between which the first hydrofoil 34 and the second hydrofoil 36 extend. Each hydrofoil 34, 36 is slidably and rotatably connected to the structure, allowing each hydrofoil to move linearly in a heave motion and swing about a spanwise axis in a pitch motion. In this configuration of the turbine 30, the heave motion is vertical and each hydrofoil 34, 36 oscillates about a horizontal axis. Preferably, hydrofoils 34, 36 each have a rectangular or untwisted configuration. Still preferably, each hydrofoil is symmetrical in cross-section and its surface is curved.

Turning now to FIGS. 5 , 5A and 5B , a third embodiment of a turbine 30 is shown. In this case, the hydrofoils 34, 36 each comprise a pair of foils 40a, 40b extending in parallel between the posts. The foils 40a, 40b are rigidly connected via rigid links, in this case reinforcing plates 42 distributed along the span of the hydrofoil. The ends of the hydrofoil also have end plates 44a, 44b which facilitate the connection of the hydrofoil to other components of the turbine while reducing the adverse effects of wingtip vortices. As best shown in Figure 5A, the multi-faceted hydrofoil 34 is constructed of pairs of foils that are adjacently spaced so as to be a double foil. Such a configuration increases the stiffness of the foil 34 allowing the use of a higher aspect ratio, which is the ratio of the length (span) to width (chord) of the foil. A hydrofoil with a higher aspect ratio increases lift and thrust capability while maintaining its width and thus system compactness. As best seen in Figure 5B, two foils 40a, 40b are located on each side of the pitch axis 46 of the hydrofoil.

This configuration of the hydrofoil also facilitates modular manufacturing, where the overall length of the hydrofoil can be adjusted, ie increased or decreased, for a particular application using the same basic components. This modular configuration may also facilitate the transportation of the hydrofoils.

It will be appreciated that the hydrofoils 34, 36 may consist of a single lifting surface, or alternatively incorporate multiple lifting surfaces rigidly connected to each other.

The mechanisms involved in the oscillating motion of the hydrofoil can be divided into two main parts according to their respective tasks. The first task is to couple a linear or pitching motion into an alternating rotational or pitching motion. This first task is achieved with a heave-pitch assembly where a pitch-heave coupling is used to obtain a 1 degree of freedom system. The second part deals with coupling linear oscillatory motion into rotational motion. This second task is achieved in a linear-rotary transmission system with a power transmission link between the hydrofoils and the cyclic heave motion of the rotary shaft.

Floating-pitching assembly

Figures 6A to 8A illustrate alternatives that may be considered to perform this first task, while Figures 9, 9A and 9B illustrate alternatives to perform this second task. Figures 10 to 13 show a turbine with components of a heave-pitch assembly and a linear-rotary transmission system when combined.

Referring now to FIG. 6A , a schematic diagram of the heave-pitch assembly 48 incorporating the first hydrofoil 34 and the second hydrofoil 36 is shown. The hydrofoils 34, 36 are slidable and rotatable, allowing them to move linearly in a heave motion y ₁ , y ₂ and to swing about the spanwise axis in a pitch motion θ ₁ , θ ₂ . The heave-pitch assembly allows coupling the heave motion y ₁ , y ₂ of the first hydrofoil 34 and the second hydrofoil 36 to the pitch motion θ ₁ , θ ₂ of the second and first hydrofoil 36 , 34 respectively .

Figure 6B shows the heave and pitch motion of the hydrofoils 34, 36, either sinusoidal or quasi-sinusoidal. In this figure, the heaving motion of the first hydrofoil 34 is represented by the curve y ₁ and its pitching motion is represented by the curve θ ₁ . Similarly, for the second hydrofoil 36, its heave motion is represented by curve y ₂ and its pitch motion is represented by curve θ ₂ .

As can be appreciated, for a given hydrofoil, its heave and pitch motions are out of phase by one pitch-heave motion phase, which is equal to Pi/2 or 90 degrees, which corresponds to T/4. It can also be observed that the heave motion y ₁ of the first hydrofoil 34 is out of phase with respect to the heave motion y ₂ of the second hydrofoil 36 by an inter-hydrofoil phase. While the pitch-heave phase of a hydrofoil is typically Pi/2, the heave-pitch assembly 48 sets the inter-foil phase between _y1 and _y2 to also be equal to Pi/2, making it possible to The heave motion of the foil is used to drive the pitch motion of its neighboring foils.

Returning to FIG. 6A, the heave-pitch assembly 48 includes a pair of first and second linear actuators 50, 52, a pair of first and second rotary actuators 54, 56 and heave - Elevation coupling system 58 .

A first linear actuator 50 is connected to the first hydrofoil 34 and a second linear actuator 52 is connected to the second hydrofoil 36 . As the hydrofoils 34 , 36 move linearly (eg, in a heave motion induced by the water flow), the corresponding linear actuators 50 , 52 are driven by the heave motion. In the present case, the first and second linear actuators 50, 52 are hydraulic cylinders.

Similarly, a first rotary actuator 54 is connected to the first hydrofoil 34 and a second rotary actuator is connected to the second hydrofoil 36 . A pitch-pitch coupling system 58, preferably consisting of hydraulic tubing, is used to couple the first linear actuator 50 to the second rotary actuator 56, and to couple the second linear actuator 52 to the first rotary actuator. 54.

As the first hydrofoil 34 moves linearly under turbulent flow conditions, fluid is pushed out of the cylinder 50 through the tube 58 , which in turn drives the rotary actuator 56 , thereby driving the pitching motion of the hydrofoil 36 . The same relationship exists between the hydrofoil 36 , the cylinder 52 and the rotary actuator 54 . The hydraulic cylinders 50, 52 and rotary actuators 54, 56 are sized and configured such that the phase between the foils is equal to a heave-pitch phase of 90 degrees.

Preferably, as shown in FIGS. 3 , 4 and 5 , hydraulic cylinders 50 , 52 , rotary actuators 54 , 56 and coupling system 58 are housed within a basic structure, in this case column 38 .

To reduce the operating pressure of the hydraulic cylinders, it was possible to double the components of the heave-pitch assembly. In this case, embodiments such as those shown in FIGS. 4 and 5 (ie, having two posts 38 ) allow the first post 38 a to accommodate a first pair of linear actuators 50 , 52 , a first pair of rotary actuators, and a first pair of rotary actuators. actuators 54, 56 and the first heave-pitch assembly. The turbine also includes a second column 38b housing a second pair of linear actuators 50 , 52 , a second pair of rotary actuators 54 , 56 and a second sink-float coupling system 58 .

Referring now to FIG. 7 , the connection between the first hydrofoil 34 , the first linear actuator 50 and the second rotary actuator 56 is shown. The pitch axis 46 of the hydrofoil 34 is rigidly connected to a bilateral cylinder 50 and to a rotary actuator 56 . The two outlets 60 a , 60 b of the double sided hydraulic cylinder 50 are connected to the inlets 62 a , 62 b of the rotary actuator 56 . In the present case, the rotary actuator 56 is a single airfoil actuator. In Fig. 7, the second hydrofoil 36 is not shown for greater clarity, but of course the second hydrofoil 36 is indeed connected to the second rotary actuator 56, as shown in Fig. 7A.

Preferably, the heave-pitch assembly includes a pitch control mechanism 74 for controlling the pitch amplitude of the respective hydrofoil. In the present case, this mechanism 74 consists of brakes 64a, 64b and safety valves 66a, 66b. The fluid volume of the actuator 56 is designed to be slightly smaller than the fluid volume displaced by the hydraulic cylinder 50 . This causes the automatic referencing system to run when needed. The extra fluid ensures that the blades 68 reach the brakes 64a, 64b such that a preset maximum pitch amplitude is achieved. Once the airfoil 68 contacts one of the brakes 64a, 64b, the pressure rises and additional fluid (preferably environmentally friendly, such as filtered ambient water) is injected through the relief valve 66a, 66b.

Another embodiment of the pitch control mechanism 74 is shown in FIG. 7B . In this case, active devices are used. The positive displacement pump 76 (which is mechanically or otherwise controlled by the controller 78) periodically resets the pitch-heave motion phase.

Returning to Figure 7, mechanical friction should be avoided as much as possible to reduce maintenance. Preferably, hydrostatic bearings 70a, 70b are used instead of contact seals in each hydraulic cylinder and actuator. The hydrostatic bearings 70a, 70b are fed by an external pump 72 which operates at a higher pressure than the hydraulic fluid. In addition to providing directed and non-contact operation of the hydraulic cylinder 50, the hydrostatic bearing ensures replacement of any loss of hydraulic fluid in the system. Alternatively, the rotary actuator vane 68 may also be provided with a low friction sealant, such as Teflon, UHMW, or the like.

Turning now to Figure 8, another type of rotary actuator is shown. In this case, the rotary actuator 56 comprises a drum-cable mechanism. In such a mechanism, the pitch axis 47 of the second hydrofoil 36 is rigidly connected to the axis of the drum 82b. A cable 84 is rigidly connected to the drums 82a, 82b and driven by a linear twin-rod hydraulic cylinder 86 . The brakes 64a, 64b and safety valves 66a, 66b can also use this type of rotary actuator 56 to control the pitch amplitude of the hydrofoil. Alternatively, as shown in Figure 8A, a controlled displacement pump 76 may be used instead.

Linear-Rotary Transmission System

Referring to Figures 9, 9A and 9B, portions of a linear-rotary transport system 88 are shown. This portion of the linear-to-rotary transmission system 88 is operatively connected to the first hydrofoil 34 and to the rotational shaft 90 such that the heave motion of the first hydrofoil drives the rotational motion of the shaft 90 . Of course, another part of the linear-rotary transmission system is connected to the second hydrofoil 36, but this is not shown in the figure for clarity.

As shown in either embodiment of FIGS. 9A and 9B , the linear-rotary transmission system 88 linked to the first hydrofoil 34 includes a transmission actuator 92 operatively connected to said hydrofoil 34 , which in this In this case hydraulic cylinder 92 . The hydraulic cylinder 92 is rigidly connected to the hydrofoil 34 . System 88 also includes a linear-rotary transmission chain 94 for converting linear motion of transmission actuator 92 into rotational motion of shaft 90 .

As can be appreciated, the two embodiments of the linear-rotary chain 94 shown in FIGS. 9A and 9B allow the transmission actuator 92 and thus indirectly the hydrofoil 34 to be coupled to the rotational axis 90 . The buoyancy power of the hydrofoils 34 is converted in the form of rotational motion of the shaft, which may be part of the generator, thereby generating electricity.

Referring to Figure 9A, the transmission chain 94 includes two single sided hydraulic cylinders 96a, 96b connected to crankshafts 98a, 98b. In an alternative embodiment shown in FIG. 9B , the hydraulic cylinders 96a, 96b are connected to a hydraulic shaft piston motor 100 . Of course, other types of transmission chains 94 are also conceivable.

Returning to Figure 9, the displacement volume of the dual sided hydraulic cylinder 92 preferably matches the total volume of the single sided hydraulic cylinders 96a, 96b. However, a relief valve 102a, 102b is added to each tube to allow for any mismatch in fluid volume.

Preferred Embodiments of Turbines and Propulsion Systems

FIG. 10 shows another preferred embodiment of the linear-rotary transfer system 88, wherein the first and second transfer actuators 92, 93 and the first and second rotary actuators 54 , 56 are connected to the double-sided hydraulic cylinders 104a, 104b, 104c and 104d. The cylinders 104a, 104c are connected to the same rod 106 . Similarly, cylinders 104b, 104d share rod 108 .

This embodiment may be advantageous for applications where several turbines 30 are arranged together, such as tidal fields, also known as hydrodynamic turbine parks, where the linear-rotary transmission system of each turbine unit 30 is connected to the same shaft of rotation and power generation machines where the phase of relative motion between the turbines is set in such a way as to further smooth the applied torque and rotational speed.

Preferably the hydraulic fluid is low pressure (about 150 psi) and consists of conditioned water or vegetable oil which limits energy loss (minimum friction in hoses and leakage in ambient water) and ensures environmentally friendly operation.

It should also be noted that the 90 degree inter-foil phase in the hydrofoils of a base unit pair implies relative motion of each foil to its neighbors. Therefore, the hydraulic hoses interconnecting the hydraulic cylinder and the rotary actuator need to allow this relative movement.

Advantageously, the 90 degree inter-foil phase allows avoiding the two foils 34, 36 from reaching their zero production points (top and bottom positions), while it effectively flattens the torque signal of the generator and makes the entire Turbine starts automatically. Preferably, the heave-pitch assembly and linear-rotary transmission system 88 are sufficiently compact that most of the components fit inside the two side columns 38a, 38b forming the foundation structure. By doing so, most of the components are shielded from the flowing water while keeping the hydrofoils exposed.

11 and 11A, the heave-pitch coupling system 58 (comprising hydraulic tubes interconnecting the linear actuators 50, 52 and the rotary actuators 54, 56) may incorporate some lengths of coaxial slide tubes 110, 112, 114 , 116 so that the hydraulic circuit can account for the relative motion between the two hydrofoils 34, 36 while maintaining a constant total fluid volume. Figure 11A also provides a complete overview of the preferred mechanism with rotary actuators 54, 56 rigidly connected by rigid links 118, 120 to their respective pitch-heave coupled hydraulic cylinders 50, 52, Connected to their linear-rotary transfer cylinders 92 , 93 and to their associated slide tubes 110 , 112 , 114 , 116 .

Referring to Figure 12, to facilitate the alignment of the hydraulic cylinders (which are part of the heave-pitch assembly and part of the linear-rotary transmission system), and to further improve the compactness of the entire mechanism, it is possible to rely on coaxial hydraulic cylinders 122, 124 use. Coaxial cylinders 122, 124 may also be used in conjunction with coaxial slide tubes, similar to the embodiment shown in FIG.

Referring to Figure 13, the turbine 30 can be further simplified by incorporating hydraulic cylinders associated with the hydrofoils 34 or 36 for both the heave-pitch assembly in a single hydraulic cylinder 126 or 128 and for the linear-rotary system.

In this embodiment of the turbine 30 , a linear-rotary transmission chain 94 is connected to the shaft 90 and two transmission cylinders 126 , 128 are each connected to the linear-rotational transmission chain 94 .

The first hydraulic cylinder 126 comprises a rod 130 and two pistons 134 a , 134 b at both ends of the rod 130 , each piston marking the edges of the first and second chambers on either side of the cylinder 126 . The second hydraulic cylinder 128 has a similar configuration with a rod 132 and pistons 136a, 136b. The rods 130, 132 are preferably hinged to facilitate their alignment and displacement. Each rod 130 , 132 is connected to a corresponding one of the hydrofoils 34 , 36 . For a given cylinder 126 or 128, the first chamber 138 is connected to its corresponding rotary actuator 56, 54 via coupling means and the second chamber 140 is connected to the transfer cylinder 96a, 96b. Rotary shaft 90 , which moves in constant rotational movement, may be coupled to generator 144 by any means 142 . In this preferred embodiment of the turbine 30, the hydraulic cylinders 126, 128 are part of the heave-pitch assembly and linear-rotary transmission system. 13A and 13B show alternatives to rotary actuators 54,56. In Fig. 13A, the rotary airfoil actuator 67 is shown, while in Fig. 13B, the reel and cable mechanism 75 is shown.

Referring to FIG. 14 , a modification of the embodiment shown in FIG. 10 results in yet another embodiment of the present invention, which consists of a propulsion system 146 . System 146 allows operation of first swinging hydrofoil 34 in a transmission-like compact arrangement for propulsion rather than power extraction. Although not shown, the same type of components and connections may be used for the second hydrofoil, the two hydrofoils being coupled, such as shown in FIG. 10 . The propulsion system 146 allows for the transfer of mechanical energy from the rotating drive shaft 90 . The propulsion system includes the same components of the turbine 30, namely: the support structure, the first and second hydrofoils, the heave-pitch assembly and the rotary-linear transmission system. In contrast to the turbine 30, in the propulsion system 146, the rotational motion of the drive shaft in turn drives the heave and pitch motion of the hydrofoil.

Method for converting kinetic energy from fluid flow to mechanical energy

Referring to Figures 1 to 13, the method for converting kinetic energy from a fluid flow to mechanical energy requires a turbine comprising a first hydrofoil and a second hydrofoil each movable linearly in a heave and buoy motion and capable of Swing around the spanwise axis in a pitching motion, where the heave and pitch motions are quasi-sinusoidal. For a given one of the hydrofoils, the heave and pitch motions are out of phase by one pitch-heave motion phase, and the respective heave motions of the first hydrofoil and the second hydrofoil are out of phase by an inter-hydrofoil phase. This method requires coupling the heave motion of the first hydrofoil and the second hydrofoil to the pitch motion of the second hydrofoil and the first hydrofoil, respectively. This coupling is achieved with a pitch-heave motion phase substantially equal to the interfoil phase. This advantageously allows the heave motion of one of the hydrofoils to drive the pitch motion of the other hydrofoil. The method also requires the use of a linear-to-rotary transmission to convert the ups and downs of the hydrofoils into rotational movement of the rotary shaft.

Preferably, the method comprises the sub-steps of providing a pair of first and second linear actuators, a pair of first and second rotary actuators and a heave-pitch coupling system. The first linear actuator is connected to the first hydrofoil, and the second linear actuator is connected to the second hydrofoil, each of the first linear actuator and the second linear actuator is connected by the ups and downs of the corresponding hydrofoil drive. The first rotary actuator must also be connected to the first hydrofoil, and the second actuator to the second hydrofoil, each first and second rotary actuator driving the corresponding hydrofoil. Finally, with a heave-pitch coupling system, the first linear actuator is coupled to the second rotary actuator, and the second linear actuator is coupled to the first rotary actuator.

Still preferably, the method comprises the sub-step of providing two spaced columns, a first hydrofoil and a second hydrofoil extending between the two columns. The first hydrofoil and the second hydrofoil each include a pair of foils extending in parallel between the posts.

Performance is also improved at pitch-heave motion phases and interfoil phases of approximately 90 degrees. Preferably, the method further includes the step of controlling the pitch amplitudes of the first hydrofoil and the second hydrofoil.

The turbine described above offers a clear advantage at the submerged site due to its rectangular receiving surface, allowing the possibility of extending the rated power by simply increasing the span of the turbine's hydrofoils. Furthermore, the untwisted rectangular hydrofoils in the swing concept have a simpler geometry and are easier to produce than typical rotor blades.

For tidal operation, where the turbine should be capable of low tide and high tide operation, ie in two opposite directions, the system is reversible by rotating the hydrofoils through 180 degrees. This can be performed by mounting each foil's rotary actuator on an additional 0-180° hydraulic actuator which can be fed on demand by a pump feeding the hydrostatic bearing . Alternatively, the pitch center where the foil engages its structural uprights can be incorporated into a clutch coupling. In such an embodiment, the 180° rotation of the foil can be passively initiated from the action of the water flow. A change in phase is also necessary to accomplish turbine reversal.

This is preferably achieved by commutating the rotational movement of the generator with an electric drive.

Oscillating foils produce effective propulsion when operated at proper pitch angles. The embodiments presented above may be used for propulsion purposes in applications intended to generate thrust from oscillating hydrofoils. In such cases, the generator would operate as a motor and the work would be performed by foils on the fluid rather than energy extracted from the fluid flow.

Many modifications may be made to the above embodiments without departing from the scope of the invention.

Claims (35)

1. one kind is used for kinetic energy being converted to the turbo machine of mechanical energy from flow by driving running shaft, and described turbo machine comprises:

-supporting structure;

-extension is from the first hydrofoil and second hydrofoil of described supporting structure, each hydrofoil slidably and be rotationally attached to described structure, thereby allow each mode with plunging motion of described hydrofoil to move linearly and swing with the mode spanwise axes of pitching movement; Described sink-float and pitching movement are quasi sine, wherein:

-for given one in described hydrofoil, described sink-float and pitching movement out-phase reach a pitching-plunging motion phase place, and

The described out-phase of plunging motion separately of-described the first hydrofoil and described the second hydrofoil reaches phase place between a hydrofoil; With

-sink-float-pitching assembly, it is used for the described plunging motion of described the first hydrofoil and described the second hydrofoil is coupled to respectively the described pitching movement of described the second hydrofoil and the first hydrofoil, described pitching-plunging motion phase place equals phase place between described hydrofoil substantially, thereby the described plunging motion of one of described hydrofoil drives the described pitching movement of described another hydrofoil; With

-may be operably coupled to described the first hydrofoil and described the second hydrofoil and be connected to the linearity of described running shaft-rotary transfer system, thus the described plunging motion of described the first hydrofoil and described the second hydrofoil drives rotatablely moving of described axle.

2. turbo machine according to claim 1, wherein said coupling-sink-float assembly comprises:

-a pair of the first linear actuators and the second linear actuators, described the first linear actuators is connected to described the first hydrofoil, and described the second linear actuators is connected to described the second hydrofoil, and each of described the first linear actuators and described the second linear actuators drives by the described plunging motion of described corresponding hydrofoil;

-a pair of the first revolving actuator and the second revolving actuator, described the first revolving actuator is connected to described the first hydrofoil, and described the second revolving actuator is connected to described the second hydrofoil, and each mode with described pitching movement of described the first revolving actuator and described the second revolving actuator drives described corresponding hydrofoil; With

-sink-float-pitching coupled system, it is used for described the first linear actuators is coupled to described the second revolving actuator, and is used for described the second linear actuators is coupled to described the first revolving actuator.

3. turbo machine according to claim 1 and 2, wherein said supporting structure comprises a post, described the first hydrofoil and described the second hydrofoil extend on the opposite side of described post.

4. turbo machine according to claim 1 and 2, wherein said supporting structure comprises that two separate post, described the first hydrofoil and described the second hydrofoil extend between described post.

5. the described turbo machine of any one according to claim 1 to 4, wherein each described hydrofoil has elongated and main body general planar.

6. the described turbo machine of any one according to claim 1 to 5, wherein each described hydrofoil has the extension crooked outline.

7. turbo machine according to claim 6, wherein each described hydrofoil has symmetrical cross section.

8. the described turbo machine of any one according to claim 1 to 7, wherein said the first hydrofoil and described the second hydrofoil comprise the paillon foil that pair of parallel is extended separately.

9. turbo machine according to claim 8, wherein for each described hydrofoil, described right paillon foil connects rigidly via stiff chain.

10. the described turbo machine of any one according to claim 2 to 9, wherein said the first linear actuators and described the second linear actuators are oil hydraulic cylinder.

11. turbo machine according to claim 10, wherein said oil hydraulic cylinder and described the first revolving actuator and described the second revolving actuator are contained in described fondational structure.

12. turbo machine according to claim 2, wherein:

-described fondational structure comprises that two separate post, and described the first hydrofoil and described the second hydrofoil extend between described post.

-described the first right linear actuators and the second linear actuators are first pair of linear actuators, described is first pair of revolving actuator to the first revolving actuator and the second revolving actuator, and described sink-float-pitching coupled system is the first sink-float-pitching coupled system, and wherein said first pair of linear actuators, described first pair of revolving actuator and described the first sink-float-pitching system are contained in described the first post;

Described turbo machine also comprises:

-the second pair of the first linear actuators and the second linear actuators, wherein for described second pair, described the first linear actuators is connected to described the first hydrofoil, and described the second linear actuators is connected to described the second hydrofoil;

-the second pair of the first revolving actuator and the second revolving actuator, wherein for described second pair, described the first revolving actuator is connected to described the first hydrofoil, and described the second revolving actuator is connected to described the second hydrofoil; With

The-the second sink-float-pitching coupled system, wherein for described second pair of linearity and revolving actuator, described the first linear actuators is coupled to described the second revolving actuator, and described the second described the first revolving actuator of linear actuators coupling; With

The linear actuators of wherein said second pair, revolving actuator and the described second sink-float-pitching coupled system of described second pair are contained in described the second post.

13. the described turbo machine of any one according to claim 2 to 12, wherein each described revolving actuator is single wind wing actuator.

14. the described turbo machine of any one according to claim 2 to 12, wherein each described revolving actuator comprises reel and cable mechanism.

15. according to claim 1 to 14 described turbo machine, wherein said sink-float-pitching assembly comprises the elevating control mechanism be used to the pitching amplitude of controlling described corresponding hydrofoil.

16. turbo machine according to claim 15, wherein said elevating control mechanism comprises the safety valve that combines with break or controlled displacement pump.

17. the described turbo machine of any one according to claim 1 to 16, between wherein said pitching-plunging motion phase place and described hydrofoil, phase place is about 90 degree.

18. turbo machine according to claim 10, wherein each oil hydraulic cylinder is coaxial oil hydraulic cylinder, thereby is conducive to the aligning of described the first linear actuators and the second linear actuators.

19. the described turbo machine of any one according to claim 1 to 18, wherein said linearity-rotary transfer system comprises:

-at least two transmission actuators, each may be operably coupled to the described hydrofoil of corresponding; With

-linearity-rotary transfer chain, it converts the described of described axle to for the linear motion with described transmission actuator and rotatablely moves.

20. turbo machine according to claim 10, wherein said linearity-rotary transfer system comprises:

-be connected to the linearity of described axle-rotary transfer chain;

-at least two transmission cylinders, its each be connected to described linearity-rotary transfer chain; And

Wherein:

-each oil hydraulic cylinder comprises bar and two pistons that are positioned at the two ends of described bar, and each piston is delimited the first Room and the second Room in the both sides of described cylinder,

-each bar is connected to the described hydrofoil of corresponding, and described the first Room is connected in described revolving actuator one via described sink-float-pitching coupling device, and described the second Room is connected to one in described at least two transmission cylinders;

Thereby-each oil hydraulic cylinder becomes the part of described linearity-rotary transfer system.

21. turbo machine according to claim 20, wherein for each described oil hydraulic cylinder, described bar is hinged.

22. the described turbo machine of any one according to claim 1 to 21, wherein said flow are current and described turbo machine is the fluid dynamic turbo machine.

23. the described turbo machine of any one according to claim 1 to 21, wherein said flow is air stream, and described turbo machine is wind turbine.

24. one kind is used for kinetic energy being converted to the method for mechanical energy from flow, described method comprises the steps:

A) provide turbo machine, described turbo machine comprises the first hydrofoil and the second hydrofoil, each described hydrofoil can move linearly in the mode of plunging motion and can swing with the mode spanwise axes of pitching movement, and described sink-float and pitching movement are quasi sine, wherein:

-for given one in described hydrofoil, described sink-float and pitching movement out-phase reach a pitching-plunging motion phase place, and

The described out-phase of plunging motion separately of-described the first hydrofoil and described the second hydrofoil reaches phase place between a hydrofoil;

B) the described plunging motion of described the first hydrofoil and described the second hydrofoil is coupled to respectively the described pitching movement of described the second hydrofoil and the first hydrofoil, wherein said pitching-plunging motion phase place equals phase place between described hydrofoil substantially, thereby the described plunging motion of one of described hydrofoil drives the described pitching movement of described another hydrofoil; With

C) utilize linearity-rotation transmission device to convert the described plunging motion of described hydrofoil to running shaft in rotary moving.

25. method according to claim 24, wherein step b) comprise following substep:

I) provide a pair of the first linear actuators and the second linear actuators, a pair of the first revolving actuator and the second revolving actuator and sink-float-pitching coupled system;

Ii) described the first linear actuators is connected to described the first hydrofoil, and described the second linear actuators is connected to described the second hydrofoil, and each of described the first linear actuators and the second linear actuators drives by the described plunging motion of described corresponding hydrofoil;

Iii) described the first revolving actuator is connected to described the first hydrofoil, and described the second actuator is connected to described the second hydrofoil, and each mode with described pitching movement of described the first revolving actuator and the second revolving actuator drives described corresponding hydrofoil; With

Iv) with described sink-float-pitching coupled system, described the first linear actuators is coupled to described the second revolving actuator, and described the second linear actuators is coupled to described the first revolving actuator.

26. according to claim 24 or 25 described methods, wherein step a) comprises and provides two to separate post by following substep, and described the first hydrofoil and described the second hydrofoil extend between described post.

27. the described method of any one according to claim 24 to 26, wherein a) described the first hydrofoil and described the second hydrofoil comprise the paillon foil that pair of parallel is extended to step separately.

28. the described method of any one according to claim 24 to 27 is wherein at step b) in, between described pitching-plunging motion phase place and described hydrofoil, phase place is about 90 degree.

29. according to claim 24 to 28, the described method of any one, also comprise the steps, controls the pitching amplitude separately of described the first hydrofoil and described the second hydrofoil.

30. one kind is used for from the propulsion system of rotating driveshaft transmit machine energy, described system comprises:

-supporting structure;

-extension is from the first hydrofoil and second hydrofoil of described supporting structure, each hydrofoil slidably and be rotationally attached to described structure, thereby allow each described hydrofoil to move linearly in the mode of plunging motion and swing with the mode spanwise axes of pitching movement; Described sink-float and pitching movement are quasi sine, wherein:

-for given one in described hydrofoil, described sink-float and pitching movement out-phase reach a pitching-plunging motion phase place, and

The described out-phase of plunging motion separately of-described the first hydrofoil and described the second hydrofoil reaches phase place between a hydrofoil; With

-sink-float-pitching assembly, it is used for the described plunging motion of described the first hydrofoil and described the second hydrofoil is coupled to respectively the described pitching movement of described the second hydrofoil and the first hydrofoil, described pitching-plunging motion phase place equals phase place between described hydrofoil substantially, thereby the described plunging motion of one of described hydrofoil drives the described pitching movement of described another hydrofoil; With

-rotation-linear transfer system, it may be operably coupled to described running shaft and is connected to described the first hydrofoil and described the second hydrofoil, thus described the rotatablely moving of described live axle drives described sink-float and the pitching movement of described hydrofoil.

31. a hydrofoil that comprises the paillon foil that pair of parallel is extended, described paillon foil connects via stiff chain.

32. hydrofoil according to claim 31, each of wherein said paillon foil have main body elongated and flat.

33. according to claim 31 or 32 described hydrofoils, each of wherein said paillon foil has the extension crooked outline.

34. the described hydrofoil of any one according to claim 31 to 33, each of wherein said paillon foil have symmetrical cross section.

35. the described hydrofoil of any one according to claim 31 to 34, wherein said stiff chain comprises the stiffening plate that distributes along described hydrofoil on spanwise, to be used for providing extra paillon foil rigidity.

Images