Abstract: A flywheel device includes a base, a cantilever mounted on the base, a bearing seat mounted on the base, first magnetic members mounted on the base, a rotation shaft arranged between the cantilever and the bearing seat, a magnetically floating seat mounted on the rotation shaft, second magnetic members mounted on the magnetically floating seat and corresponding to the first magnetic members, third magnetic members mounted on the magnetically floating seat, a repulsion driver locked on the base and surrounding the magnetically floating seat, fourth magnetic members mounted on the repulsion driver and corresponding to the third magnetic members, and a flywheel unit mounted on the rotation shaft. The second magnetic members have a polarity the same as that of the first magnetic members. The fourth magnetic members have a polarity the same as that of the third magnetic members.

Abstract: An ocean tidal current energy power generating system, including a fixing mechanism, an ocean tidal current energy power generator set and a signal monitoring mechanism. The fixing mechanism includes floating bodies, fixing rods, horizontal supporting rods, and a working platform; the floating bodies are fixed to seabed by means of anchor chains; the fixing rods are fixed to the floating bodies; the horizontal supporting rods and the working platform are respectively fixed to underwater portions of the fixing rods and overwater portions of the fixing rods. The power generator set includes underwater assemblies and an overwater assembly. Each underwater assembly includes blades, a hub, a main shaft, a gear box, a coupling, a power generator, a stern cabin and a yawing mechanism, successively connected to each other; a variable pitch mechanism is disposed in the hub.

Abstract: A wind energy, wave energy and tidal energy integrated power generation system based on monopile foundation, in which the wind energy, wave energy and tidal energy will share the support structure and power transmission system, belongs to the technical field of ocean renewable energy utilization. An integrated power generation system which integrates wind energy converter, oscillating water column wave energy converter and horizontal-axis tidal energy converter is established based on the monopile support structure. The invention makes sufficient use of offshore renewable resources, so as to improve the utilization ratio of monopile foundation and reduce the total cost of power generation of integrated system. The novel integrated power generation system improves the effective utilization of the ocean areas, reduces the cost of construction and maintenance, makes full use of the existing mature wind energy technology, and promotes the commercialization of wave energy converters and tidal energy devices.

Abstract: A propulsion system (102) for an aquatic vessel (100) is provided. The propulsion system includes a plurality of Magnus-type rotors (108) and a drive arrangement (147) for rotating the plurality of Magnus-type rotors. The plurality of Magnus-type rotors are operable to rotate about corresponding substantially upright axes. The propulsion system also includes a control arrangement (150) for controlling the drive arrangement to vary rates of rotations of the plurality of Magnus-type rotors. Each of the plurality of Magnus-type rotors includes a hollow region (116) therein. Each of the Magnus-type rotors is rotationally supported onto a support arrangement (118) which extends into the hollow region. The drive arrangement includes at least one motor (148) disposed in the hollow region and located outside the support arrangement such that the at least one motor is accessible for maintenance.

Abstract: The invention disclosed herein comprises a system focusing water current into a relatively smaller diameter lumen, imparting vortical movement to the current, and directing the water vortex through an even smaller diameter lumen en route to turbine blades having long curved blades rotatable along an axis parallel with the lumen. Rotation of the turbine blades turns gearing interfacing with the circumference of the turbine assembly, to rotate a drive shaft connected to a generator.

Abstract: A submersible turbine generator unit can be placed in rivers, streams, or anywhere water flows in order to generate electricity without the need for dams. It is designed to work with its own diversion equipment for controlling and directing a flow of water into the turbine blades. The unit can be raised and lowered in the flow to enhance efficiency, respond to changing flow conditions, and for inspection/servicing, etc. The positioning system can use a motorized worm gear and a rack to raise or lower the turbine generator combination. Once raised up, a hard connection point allows attachment of a lifting cable so the turbine/generator combination can be easily removed and replaced as needed. A submersible turbine generator utilizes uniquely shaped turbine blades that efficiently engage flowing water and spin the turbine shaft without presenting undue risk to aquatic life.

Abstract: Mechanical systems and methods including, in some embodiments, a mounting plate affixed to an exterior facing horizontal planar deck surface of a ship; a foundation structure mounted to the mounting plate and supporting at least a first sail cylinder and a second sail cylinder; and at least a first lift mechanism for selectively vertically driving the first and second sail cylinders from a vertically retracted position to a vertically deployed position.

Abstract: A conical fan assembly, having a generally conical support member having an exterior surface and a vertical major axis, and a plurality of generally crescent-shaped fan blades extending from the exterior surface of the support member, wherein the plurality of fan blades define a helix configured to urge a fluid to flow in a spiral flow pattern up and around the support member.

Abstract: A respiratory treatment device comprising at least one chamber, a chamber inlet configured to receive air into the at least one chamber, at least one chamber outlet configured to permit air to exit the at least one chamber, and a flow path defined between the chamber inlet and the at least one chamber outlet. A restrictor member positioned in the flow path is moveable between a closed position, where a flow of air along the flow path is restricted, and an open position, where the flow of air along the flow path is less restricted. A vane in fluid communication with the flow path is operatively connected to the restrictor member and is configured to reciprocate between a first position and a second position in response to the flow of air along the flow path.

Abstract: The Vortex Hydro Turbine takes water through two upper inlets and one lower inlet from the current in which it is submerged. The upper inlets direct the water flow into cylindrical chambers with a spiral bottom to create a vortex. The top of the chambers are specifically left open to allow the water to exit and to reintegrate into the existing native flow. This movement of the water creates a low pressure area within the center of each of the chambers which is transferred to the back side of a turbine blade system through depending tubes. Water flows thru the turbine blade via the lower inlet and out the tail pipe. The low pressure from the depending tubes, aft of the blades, increases the water velocity through the blades for increased power output. The system can be scaled as a standalone unit or as an array.

Abstract: The present invention provides a water flow regulating device and an ocean power generating device using the same. The water flow regulating device includes a main body, a water deflector, a rotating shaft, a winding shaft, a rope or cable, and a driving unit. The water deflector is pivotally connected with the main body. The rotating shaft is rotatably disposed at the main body. The winding shaft is disposed at the main body. One end of the rope or cable is fixed to the water deflector, and the other end bypasses the rotating shaft and the winding shaft, goes back to the water deflector and is fixed to the water deflector. The driving unit is connected with the rotating shaft to drive the rotating shaft to rotate, such that the rope or cable is driven to withdraw or release to control the water deflector to rotate.

Abstract: The invention concerns a rotor blade for a water turbine with a hydrodynamic profile, to which a suction side and a pressure side are associated, comprising a plurality of overflow channels, which are arranged in the hydrodynamic profile and create a hydraulic connection between the suction side and the pressure side and to which a valve arrangement is associated respectively. The invention is characterised in that the valve arrangement is closed below a preset load limit threshold for the rotor blade and is opened above the load limit threshold, whereas every overflow channel with the valve arrangement in the open position reduces the power coefficient and/or the thrust coefficient of the rotor blade with respect to the closed position.

Abstract: In one aspect, there is provided a wave chamber for a wave power plant having a water inlet opening and an outlet leading to a ventilation channel including an air turbine. The wave chamber includes a free-standing stack of a plurality of chamber segments braced vertically by a large number of traction elements, where the lowest chamber segment of the plurality of chamber segments is associated at least indirectly with a thrust securing system, and where the thrust securing system contains a hollow element for insertion inserted into a bottom of a body of water.

Abstract: A hydroelectric turbine for the production of electricity from tidal flow forces, the turbine having a rotor with an open center such that the blades are mounted between an inner rim and outer rim, wherein retaining members and anti-friction members are provided to limit movement of the rotor relative to the housing in either axial direction, such that water flow in either direction operates the turbine, but wherein the retaining members and the anti-friction members allow the rotor to shift in either axial direction in response to water flow. The anti-friction members limiting rotor travel in the axial direction are preferably of increased thickness, such that as the anti-friction members wear down, the rotor is able to shift relative to the housing in the axial direction.

Abstract: A tidal turbine system includes yaw drive for rotating the turbine between a first position associated with tidal flow and a second position associated with tidal ebbs. The yaw drive is capable of moving the tidal turbine to a position where the tidal turbine is pointed substantially directly into the tidal flow in the first position and substantially into the tidal ebb in a second position. A method for harvesting tidal energy includes rotating the tidal turbine between one of the first position and the second position.

Abstract: Provide a hydroelectric power generation system that can increase generation efficiency by keeping the rotational resistance of the runner low, while preventing water contamination at the same time. The hydroelectric power generation system has: a first water storage tank 20 with a high-pressure water injection port 21 on the bottom face; a runner 40 which is stored in a condition of floating in the first water storage tank; and multiple transmission members 50 that contact the outer periphery surface of the runner and transmit the rotational force of the runner to the principal axis of rotation 61 in the generator unit 60.

Abstract: A hydraulic power generation motor includes a tubular body (4) including a pair of coupling flanges (12) formed at opposite ends thereof and an impeller housing (8) formed in an intermediate portion thereof, the coupling flanges (12) being connectable to fluid conduits (10) through which fluid flows. An impeller (38) is rotatably installed within the impeller housing (8) of the tubular body (4), the impeller (38) being designed to be rotated by the fluid and operatively connected to a generator (40) for generating an electric power.

Abstract: The invention refers to a hydrokinetic unit which allows a high level exploitation of the energetic potential of rivers in the plain regions, where the flat relief does not allow to build dams or culverts and which is destined to convert the kinetic energy of flowing waters into useful mechanical energy for producing electric energy or for pumping water by using such modular hydrokinetic assemblies equipped with generators or pumps. The hydrokinetic unit according to the invention comprises a threshold (1) of a constant level provided with flaps (2) and two catching connectors (3) with protection grids (4) and, one or more connections (5) with the flaps which regulate the water flow rates necessary for driving the modular hydrokinetic assemblies (6), connected to the catching connector (3) and, which may be equipped with electric generators or water pumping groups.

Abstract: An object of the present invention is to provide a natural energy extraction apparatus comprising a vertical rotating shaft and a float for supporting the vertical rotating shaft, wherein the internal structure of the float is simpler, the float and a mooring apparatus are more compact, and production cost is lower than in the conventional natural energy extraction apparatus. A natural energy extraction apparatus comprises a first float forming a swingable vertical rotating shaft, a second float moored to surround the first float, and a power transmission device attached to the second float to convert rotational kinetic energy of the first float to driving torque for driven equipment, and the natural energy extraction apparatus is installed on a body of water.

Abstract: An apparatus that is mounted above a water current flow for generating electricity. The apparatus is oriented perpendicular to the direction of the water current flow with paddles protruding from a shaft into the water causing the shaft to rotate. Component parts mounted on three parallel shafts inter connected by gears transfer the rotational motion energy through the apparatus amplifying the velocity and storing torque in a flywheel. Each shaft has a disconnect mechanism to transfer the motion from the shaft outer end to the inner end allowing for a specific installation method that moves the motion from the point of contact with the water current flow through the apparatus to an electric generator, generating electricity.

Abstract: The invention relates to a Wells turbine, comprising a hub having a plurality of rotor blades having a drop-shaped symmetrical profile originating from a leading edge; the rotor blades have a threading line, whose course in the rotation plane of the Wells turbine deviates in relation to a radial beam associated with the respective rotor blade at least in parts of the radial extension of the rotor blade, the threading line comprising at least one curved area.

Abstract: A turbine that allows for the conversion of the kinetic energy of waterway to mechanical power for use in an energy accepting apparatus is described. The turbine has complimentary components that improve the power efficiency of the turbine. The turbine may include a blade shroud and a plurality of blades that are connected to the blade shroud. On the external surface of the blade shroud, a drive mechanism and/or a brake mechanism may be disposed. An inlet nozzle and outlet diffuser may be used in combination with the turbine. The turbine may be useful in a number of settings, including, but not limited to, streams, rivers, dams, ocean currents, or tidal areas that have continuous or semi-continuous water flow rates and windy environments.

Abstract: A Barrage apparatus is a method and device for extracting energy from flowing fluids in an open flow by means of a submerged barrage or barrages that obstruct and channel flows at increased velocities to downstream turbine power take off modules. Increasing the velocity of the flow increases the amount of power available for extraction thereby providing opportunities to extract energy from low flow sites and facilitate the use of low cost small marine turbines to provide an ecologically sound, efficient and cost effective method of renewable energy extraction from fluid flows.

Abstract: A bi-directional flow impulse type turbine arrangement (120) for use with a bi-directional reversing flow (F, F1, F2), and in particular for use with an oscillating water column power plant (110). The turbine arrangement (120) has a rotor (120), and first and second sets of guide vanes (140, 142) located on an opposite axial sides of the rotor (132) for directing the bi-directional reversing flow (F, F1, F2) to and from the rotor (132). The guide vanes (140, 142) are disposed at a greater radius and radially offset from the rotor blades (136). The turbine arrangement further comprises first and second annular ducts disposed respectively between the first and second sets of guide vanes (140, 142) and the rotor (132) for directing fluid from the guide vanes (140, 142) to the rotor blades (136).

Abstract: A subsurface wave power generation system includes a seabed mounting plate adapted for securing to a seabed, a wing having generally opposed first and second wing surfaces extending between a first and second wing ends, the second wing end being pivotably mounted to the seabed mounting plate such that pivoting motion about a pivot axis generally parallel to the mounting plate is imparted to the wing by subsurface wave action acting on the first and second wing surfaces, and a drive arm pivotably connected to the wing to convert the pivoting motion into reciprocal motion. An electrical generator can be driven by the drive arm through a slip linkage. The slip linkage includes a first stage that converts the reciprocal motion of the drive arm into rotational motion and a second stage that selectively engages the a drive shaft of the generator drive to impart the rotational motion thereto.

Abstract: The present invention provides a floating offshore wind turbine capable of suppressing yawing of a nacelle caused by a gyro effect which is a cause of adverse influence of power generating efficiency of a wind turbine and endurance of devices thereof. The floating offshore wind turbine includes a rotor which is rotated by wind, a nacelle in which a rotation shaft of the rotor is accommodated, and a tower including a turning seated bearing which supports the nacelle such that the nacelle can turn with respect to a sea surface to exert a weathercock effect. The tower is provided with yawing suppressing means which suppresses yawing of the nacelle. According to this, it is possible to suppress the yawing of the nacelle generated by a gyro effect caused by yawing generated in the floating body by waves of the sea surface.

Abstract: The invention relates to a hydraulic turbomachine comprising a runner acted upon by water, said runner having a plurality of guide vanes, a spiral housing enclosing the runner, a traverse ring having two traverse ring decks that are interconnected by cross-beams, and lengths of pipe enveloping the traverse ring, said lengths of pipe being interconnected one after the other in the circumferential direction and the flow-sections thereof tapering in the flow direction of the water.

Abstract: A hydroelectric power device equipped with a casing member that has a channel that passes through from an opening on the water entry side towards an opening on the water discharge side, a rotor having a plurality of blades that are integrally fixed respective to the rotating shaft and are disposed inside the channel of the casing member, and a tapered portion, that is provided on the opening on the water entry side of the casing, and that is formed such that the cross-sectional area of the tapered portion is gradually decreased towards the downstream side.

Abstract: A turbine system for the utilization of the energy of oceanic waves includes: a chamber that is provided with an opening at its lower end and at its upper end respectively; a duct that is open at both ends for guiding a stream of air, the lower end of the chamber being designated to be submerged in ocean water, and the opening of the upper end being connected with one of the ends of the duct; an energy unit that is mounted coaxial to such and surrounded by the duct; and a device for cleaning the rotor blades of deposits or for preventing the formation of deposits on the rotor blades.

Abstract: A system for installing and extracting a flowing water turbine below the surface of the water includes a flow inducer assembly for improving the conversation of the kinetic energy of a waterway to mechanical energy. The flow inducer assembly includes a nozzle that may be shaped as a cowling and a outlet diffuser. The system may be useful in a number of settings, including, but not limited to, streams, rivers, dams, ocean currents, or tidal areas that have continuous or semi-continuous water flow rates and windy environments.

Abstract: A tangential turbine is adapted for receiving kinetic energy from a flowing fluid and comprises a supporting shroud, a rotating runner having a hub and a plurality of radial blades spaced apart on the hub, and a means for controlling the receiving. In first embodiment the controlling means comprises a plurality of springs each connected with its ends turningly about a connecting axis being between and within the hub and the blade and between limit stops to the hub and fixedly to the blade turnable about the axis to a non-working tangential position. In second embodiment the controlling means comprises the shroud shaped into a caisson and provided with turnable aprons and capable of accommodating the runner in the air and controlling the insertion of the blades into the flow below the shroud.

Abstract: A KHP system turbine for the production of energy in an underwater environment including a yaw stop arrangement for use in flowing steams where the flow direction of water therein is changeable, including bi-directional and multi-directional current flows, so that a rotatably mounted turbine remains in an optimal position within such changing flow conditions. The KHP turbine includes a rotational portion and one or two passive yaw stop assemblies that will control turbine yaw and keep the turbine oriented to capture energy from changeable underwater current flows.

Abstract: It is provided to embody as a modularly constructed system, a waterwheel for power generation via generators with transversely extending water blades as hinged or folding blades. In this regard it is provided to arrange the water blades over a truss framework. The truss framework for each water blade is formed by a transversely extending prism-like arrangement of plural connected struts as transverse supports, whereby these are connected at node points by longitudinal rods, and at least one strut of the transverse supports is connected with the wheel rim. In that regard, a longitudinal rod located at the top and arranged over the transverse supports is embodied for the rotatable support of a pivotably received water blade via a mounting receiver and a longitudinal rod is allocated as a counter support for the water blade in its working position. Simultaneously this longitudinal rod serves for limiting a pivoting motion of the neighboring water blade in the turbulent region.

Abstract: A power generating apparatus suitable for use in extracting energy from the movement of water, in particular tidal movement, is disclosed. The apparatus includes an elongate, generally circular in cross section, buoyancy vessel (1), having depending from its underside on a mounting means, rotatable rotor blades (2). The rotor blades are connected to a power generating means whereby in use of the apparatus movement of water across the rotor blasé, drives them so as to generate power in the power generating means.

Abstract: The present invention relates to a submersible plant for producing energy. The submersible plant comprises at least one turbine (9) and is characterized in that said turbine (9) is mounted on a stream-driven vehicle (3) and in that said stream-driven vehicle is secured in a structure by means of at least one wire (6).

Abstract: A river high pressure energy conversion machine which has no moving parts, comprising a machine (or pump) having a pipe attached to a river bed, with a flexible pipe to an enlarged water inlet attached to the underside of a float, to assure entrance of water just below the river water surface. A discharge pipe from the machine rises above the river bank to a water-driven accessory, through a stop valve and a pressure regulating valve. The discharge pipe from the accessory discharges river water back to the river. Water stacks up inside the sloping machine pipe on the river bed, and creates higher water pressure at the machine pipe outlet for driving the accessory. This is a continuous process, generating electricity twenty-four hours every day, using only gravity as the pressurizing force on water to generate electricity, without using fossil, nuclear or artificial energy forces.

Abstract: One example embodiment includes a system for extracting kinetic energy from moving fluid masses. The system includes an encapsulator, where a fluid enters the encapsulator. The system also includes decelerator, where the decelerator reduces the velocity of the encapsulated fluid to near zero velocity transferring the kinetic energy originally in the incoming fluid to the decelerator.

Abstract: The invention relates to a method and apparatus for gradually converting marine wave energy into electricity. The energy reserve provided by wind power holds enough energy for the needs of the entire mankind. The invention provides an efficient means of putting this energy reserve to practical use. Mounted on a rotating power shaft is a pair of form parts, the convex and concave shape, especially the round-pointed open V-shape of which reverses its orientation by 180 degrees, i.e. turns from convex to concave, whenever the power shaft makes a rotation of 180 degrees. The circular motion of water occurring in a wave drives such a turbine effectively while the wave dies out. The pair of convex and concave form parts extends helically around the power shaft, whereby water currents in all directions, which come to contact with the pair of form parts, produce a rotative moment.

Abstract: A dam-free hydro-power plant for generating electricity comprises a convergent-divergent water passage including a cylindrical neck containing a shutter, branch pipes connected with the neck, each branch pipe including a reverse valve capable of triggering, depending on the stream direction in the passage. A first and second branch pipes are located in front of the shutter, a third and fourth branch pipes are located behind thereof, a first and second buffers accumulating respectively higher-pressure liquid and lower-pressure liquid, the buffers are communicated through a cross-flow pipeline enclosing a turbine joined with an electro-generator. The first buffer is communicated with the neck via the first and the third branch pipe, whereas the second buffer is communicated with the neck via the second and the fourth branch pipe. The plant is highly efficient due to deploying hydro-impact, and particularly usable in places of tidal activities, in freezing rivers for all-year-round generating electricity.

Abstract: A system for improved power generation through movement of water having a turbine positioned in a moving body of water to receive kinetic energy, a blocking fitting, attachment or wall on the upper surface of the turbine to creates head potential in a moving body of water; an energy producing cell that is driven by said head potential. The energy producing cells are positioned to receive potential energy in addition to the kinetic energy from the head effect converting said energy combination or contribution by the movement of water through the cell. The system turbine may be fitted with a member positioned circumferentially about the housing for inducing a pressure drop across the turbine. The member may be a rotating blade, cantilevered duct, circumferential flange, radial eductor, and air tube for injection of ambient air into said water source.

Abstract: A buoyant hydro turbine(31) for capturing and utilizing energy in the currents of flowing water. A driven component(33) produces electricity or other energy is coupled to and supported by a buoyant rotor(64), increasing efficiency and eliminating the need for an independent supporting structure. Tethered in flowing water, the current(71) rotates the rotors(32) and transfers rotatable energy to the central driven component(33) where electricity or other mechanical work is produced. A number of embodiments are adapted for optimizing and maintaining positioning in a stream of moving water. Additional embodiments optimizing the efficiency and effectiveness of the turbine in capturing and utilizing the current's kinetic energy as well as hydrostatic pressure.

Abstract: An energy module comprising an energy absorber; and a mooring system, comprising a wing-shaped polymer shell attached to the energy absorber, the wing-shaped polymer shell designed to utilize the force of a passing current to create a downward force and thereby reduce any upward motion in the energy module; and a mooring cable housed inside the wing-shaped polymer shell and anchored to maintain the energy module in a fore and aft and a side-to-side position to provide stability, and to negate a rotational force on the energy module.

Abstract: Systems and methods use cyclical propellers with dynamic blade angle control to extract power from waves. A control system for such implementations can adapt pitching schedules for the blades of the cyclical propellers for efficient energy extraction and/or to control reactive forces. The cyclical propellers may be installed on the floor of a body of water or other liquid, on a submarine, or on a surface float, and blades may extend vertically or horizontally depending on the character of the waves. Several cyclical propellers can be combined into a single unit operated to minimize net reactive force or torque, to propel the unit horizontally or vertically, and/or to stabilize the unit. Such units can be installed with minimal or no moorings.

Abstract: The fluid-based electrical generator utilizes driven flow of a fluid to power an electrical generator for driving an external electrical device. The generator includes a reservoir having at least one sidewall and a floor. A motor coupled to a rotating shaft is mounted external to the reservoir, and a propeller is secured to the rotating shaft. The propeller is driven by the motor and is positioned within the reservoir for generating fluid flow. A rotating support having at least one vane secured thereto is rotatably secured to the floor of the reservoir, and the rotating support is driven to rotate by the fluid flow. An axle is further provided, with a lower end thereof being secured to the rotating support. The electrical generator is coupled to an upper end of the axle, with rotation of the axle driving the electrical generator to produce electricity for the external device.

Abstract: A controllable transmission system and a method thereof are provided. The controllable transmission system includes a first rotation device, a coupling device and a control device. The first rotation device includes a transmission shaft, a rotation body and a plurality of blade units connected with the rotation body, wherein each of the blade units includes an adjustable blade having a first and a second contact elements and having an opening corresponding to the adjustable blade. The coupling device is mounted beside the rotation device and includes a coupling unit having a first and a second contact surfaces. The control device is connected with the coupling device for controlling a movement of the coupling device to cause one of the contact surfaces positioned corresponding to a respective one of the first contact element and the second contact element.

Abstract: An electric power generation system that includes a platform positioned above a water surface, an anchoring system to secure the platform to a floor below a body of water, at least one turbine extending below the platform to harvest underwater ocean currents and at least one electrical generator positioned upon the platform for outputting electrical energy. The turbine includes a rotatable shaft and a plurality of rotatable blades connected to the rotatable shaft. A first rotational axis of the rotatable shaft is vertically oriented and wherein a second rotational axis of the plurality of rotatable blades is horizontally aligned with an underwater current stream. The electrical generator is mechanically connected to the shaft of the turbine to convert a rotational torque of the shaft to electrical energy.

Abstract: A hydrokinetic turbine system, including a plurality of hydrokinetic turbines is installed on a bed of a body of water. Each turbine has a shroud with a forward entrance portion and rear exit portion. The shroud includes a propeller disposed in a middle portion thereof. An inner surface of the shroud includes a plurality of rifling vanes formed therein to induce water entering the forward entrance portion to rotate in a vortex-like fashion. A plurality of pre-spin guard blades disposed adjacent the forward entrance portion also induce rotation of water and serve to provide a barrier preventing objects from passing into the forward entrance portion. A plurality of stabilizers extending from an exterior surface of the shroud that position the forward entrance portion in the direction of current flow.

Abstract: An apparatus and method for mounting underwater turbines that includes a mechanism for correcting tilt error, including both the amount and direction of error, associated with the installation of underwater turbines onto anchoring or mounting structures so that the yaw axis of the mounted turbines will be as close as possible to a desired angle, preferably vertical.

Abstract: A system for installing and extracting a flowing water turbine below the surface of the water includes a flow inducer assembly for improving the conversation of the kinetic energy of a waterway to mechanical energy. The flow inducer assembly includes a nozzle that may be shaped as a cowling and a outlet diffuser. The system may be useful in a number of settings, including, but not limited to, streams, rivers, dams, ocean currents, or tidal areas that have continuous or semi-continuous water flow rates and windy environments.

Abstract: Systems and methods use cyclical propellers with dynamic blade angle control to extract power from waves. A control system for such implementations can adapt pitching schedules for the blades of the cyclical propellers for efficient energy extraction and/or to control reactive forces. The cyclical propellers may be installed on the floor of a body of water or other liquid, on a submarine, or on a surface float, and blades may extend vertically or horizontally depending on the character of the waves. Several cyclical propellers can be combined into a single unit operated to minimize reactive forces and torques, to propel the unit horizontally or vertically, and/or to stabilize the unit. Such units can be installed with minimal or no moorings.