A wind turbine for capturing energy from a fluid flow comprises a rotor having a rotational axis and a plurality of rotor blades 104 arranged for rotation about the rotational axis. The rotor blades extend longitudinally in a direction substantially parallel to the rotational axis. A shield member V3 is arranged to shield some of the rotor blades from an oncoming wind where incidence of the wind on those rotor blades would act against rotation of the rotor in the direction of rotation. The rotor blades 104 are distributed about the circumference of the rotor and are spaced from the rotational axis, defining a substantially cylindrical space within the rotor through which the wind passes. The shield member V3 is defined by a radially inward surface and a radially outward surface. The radially inward surface follows substantially a portion of the circumference of the rotor. The radially outward surface of the shield member V3 comprises a first portion which meets the radially inward surface. In the region of the interface with the radially inward surface, the first portion extends in a first direction n that makes an angle of at least 0 degrees and up to 90 degrees in the contra-rotational direction with the radial direction of the rotor. The radially outward surface of the shield member V3 comprises a second portion which meets the first portion. At least a portion of the second portion extends in a second direction p that makes an angle of more than 0 degrees in the contra-rotational direction with the first direction n. The turbine has improved power output and efficiency compared to earlier similar designs.

A river or tidal turbine for generating a minimum predetermined value of electricity from river current received at a harnessing module comprises a harnessing module, a control module and a generating module. Han's principle is that harnessed power from a river or tidal turbine must exceed a predetermined value of control power used by the turbine. Minimum power is lost in a three variable closed mechanical control system. The three variable closed mechanical system comprises a Hummingbird control assembly of first and second spur/helical gear assemblies which may be preferably mechanically simplified. The Hummingbird control, a control motor and a generator among other components may be mounted on a floating platform for delivery of constant power at constant frequency given sufficient input from a waterwheel harnessing module driven by river current flow in at least one direction. A tidal embodiment may comprise a moveable hatch for permitting the waterwheel to turn in foe same rotational direction regardless of direction of water current flow.

The invention provides a method for computational fluid dynamics and apparatuses making enable an efficient implementation and use of an enhanced jet-effect, either the Coanda-jet-effect, the hydrophobic jet-effect, or the waving-jet-effect, triggered by specifically shaped corpuses and tunnels. The method is based on the approaches of the kinetic theory of matter, thermodynamics, and continuum mechanics, providing generalized equations of fluid motion. The method is applicable for slow-flowing as well as fast-flowing real compressible-extendable fluids and enables optimal design of convergent-divergent nozzles, providing for the most efficient jet-thrust. The method can be applied to airfoil shape optimization for bodies flying separately and in a multi-stage cascaded sequence. The method enables apparatuses for electricity harvesting from the fluid heat-energy, providing a positive net-efficiency. The method enables efficient water-harvesting from air. The method enables generators for practical-expedient power harvesting using constructive interference of waves due to the waving jet-effect.

The invention provides a method for computational fluid dynamics and apparatuses making enable an efficient implementation and use of an enhanced jet-effect, either the Coanda-jet-effect, the hydrophobic jet-effect, or the waving-jet-effect, triggered by specifically shaped corpuses and tunnels. The method is based on the approaches of the kinetic theory of matter, thermodynamics, and continuum mechanics, providing generalized equations of fluid motion. The method is applicable for slow-flowing as well as fast-flowing real compressible-extendable fluids and enables optimal design of convergent-divergent nozzles, providing for the most efficient jet-thrust. The method can be applied to airfoil shape optimization for bodies flying separately and in a multi-stage cascaded sequence. The method enables apparatuses for electricity harvesting from the fluid heat-energy, providing a positive net-efficiency. The method enables efficient water-harvesting from air. The method enables generators for practical-expedient power harvesting using constructive interference of waves due to the waving jet-effect.

A wind power generating rotor system for a wind turbine. The rotor system includes a rotor assembly having a rotor axis and a plurality of rotor blades structured and arranged for rotation around the rotor axis by wind passing the rotor blades thereby capturing kinetic energy from the wind. A diverter assembly is provided having a plurality of diverters structured and arranged at one or both of inside and outside a perimeter defined by rotation of the rotor blades thereby increasing the power of the rotor system.

A system for recovering energy from renewable sources comprises a first conduit (2) for the flow of a working fluid, heating means (3) of the fluid in the first conduit (2) adapted to promote the flow thereinside, a turbine (4) having a conveyor (5) in fluid communication with the first conduit (2) and an impeller (6) adapted to be connected to generating means (8) for the generation of energy for receiving the flow sent by the first conduit (2) and intercepted by the conveyor (5) to operate the generating means (8).

Vertical electrical energy generators are described. A vertical wind turbine system contains one or two vertical turbines, paired aside each other, and a frontal fluid flow diverter for diverting of the running fluid flow, as well as a cover, which covers the upper part of the turbine(s). The system includes an additional rear fluid flow diverter, which is installed behind one or both turbines and is configured so as to divert fluid flow running above the cover to the rear part of the turbine(s), creating secondary fluid flow in the blades of the turbine(s).

Various fluid turbine systems and methods are described. The turbine can be a vertical axis wind turbine configured to generate power from wind energy. The turbine system can have a blade assembly. The blade assembly can have a plurality of blades rotatable about an axis. The turbine system can have a concentrator positionable upwind and in front of a return side of the blade assembly. The concentrator can define a convex surface facing the wind. The turbine system can also have a variable concentrator positionable upwind of a push side of the blade assembly. The variable concentrator can be adjustable between a first position and a second position, the variable concentrator being capable of deflecting more wind toward the turbine in the first position than in the second position.

A multi-stage radial turbine for usage in energy capture from fluid streams with low to moderate relative speed.

A wind turbine device includes a rotary unit and a flow guide casing. The rotary unit includes a rotary shaft and a plurality of blades connected to and extending axially along the rotary shaft. The flow guide casing borders a blade rotating space at a downwind side of the rotary unit to allow rotation of the blades and includes an external flow pas sage that is disposed around the blade rotating space and that has an inlet and an outlet. The external flow passage is able to guide an assisting wind current to enter the inlet and to thereafter flow into the blade rotating space through the outlet for propelling the blades at the downwind side.