Abstract: A savonius wind turbine including a rotational shaft and a compound blade operatively coupled to the rotational shaft is provided. The compound blade includes a primary blade portion and a secondary blade portion. The primary blade portion extends between a first end and a second end and defines a primary concave surface therebetween. The secondary blade portion is coupled to the primary blade portion between the first end and the second end. The secondary blade portion defines a secondary concave surface configured to generate a torque about the rotational shaft.

Abstract: A vertical axis wind turbine including a nozzle is provided. The nozzle includes a first airfoil and a second airfoil. The first airfoil includes a first airfoil leading edge and a first airfoil trailing edge, and the second airfoil includes a second airfoil leading edge and a second airfoil trailing edge. The nozzle defines an inlet area disposed between the first airfoil leading edge and the second airfoil leading edge and an exit area disposed between the first airfoil trailing edge and the second airfoil trailing edge, wherein the exit area is smaller than the inlet area.

Abstract: A propulsion system (50) is disclosed. The propulsion system (50) includes a first propeller (52), a second propeller (54), and a third propeller (56). The first propeller (52), the second propeller (54), and the third propeller (56) are arranged to rotate about a common axis and the second propeller (54) is disposed between the first propeller (52) and the third propeller (56). The first and third propellers (52, 56) are configured to rotate about the common axis in a first direction (A) and the second propeller (54) is configured to rotate about the common axis in a second direction (B) opposite to the first direction (A). A first motor (60) may be coupled to the first and third propellers (52, 56) and a second motor (64) may be coupled to the second propeller (54). A first shaft (58) and second shaft (62) may be arranged along the common axis, wherein the first and third propellers (52, 56) are coupled to the first shaft (58) and the second propeller (54) is coupled to the second shaft (62).

Abstract: An exemplary vertical axis wind turbine includes a support structure rotatable about a vertical turbine axis, and at least two blades each operatively coupled to the support structure and pivotable about a respective blade axis between a fixed working position at which the blade receives a first amount of wind force and generates a torque for rotating the support structure about the turbine axis, and a neutral position at which the blade receives a lesser second amount of wind force. An exemplary method of aerodynamically braking a vertical axis wind turbine includes at least one of inhibiting a blade from reaching the fixed working position, or securing the blade in a position other than the neutral position.

Abstract: Fluid transfer controllers (FTCs) having a rotor assembly with multiple rotor blade sets coupled to a hub component of the rotor assembly and further having barrier components forming passages for routing fluid through the multiple rotor blade sets are provided. More specifically, the FTCs include passages for routing fluid along one side of a dividing structure to which a first set of rotor blades is attached and subsequently along the opposite side of the dividing structure to which a second set of rotor blades is attached. The dividing structure may be the hub component of the rotor assembly or a partition separating different levels of rotor blades within the rotor assembly. In some cases, the FTCs may be configured to route fluid from the first rotor blade set to a thermal energy alteration device and further route fluid from the thermal energy alteration device to the second rotor blade set.

Abstract: Fluid transfer controllers (FTCs) having a rotor assembly with multiple rotor blade sets coupled to a hub component of the rotor assembly and further having barrier components forming passages for routing fluid through the multiple rotor blade sets are provided. More specifically, the FTCs include passages for routing fluid along one side of a dividing structure to which a first set of rotor blades is attached and subsequently along the opposite side of the dividing structure to which a second set of rotor blades is attached. The dividing structure may be the hub component of the rotor assembly or a partition separating different levels of rotor blades within the rotor assembly. In some cases, the FTCs may be configured to route fluid from the first rotor blade set to a thermal energy alteration device and further route fluid from the thermal energy alteration device to the second rotor blade set.

Abstract: A fluid flow controller and method of operation thereof are presented. The fluid flow controller may include a casing having a casing blade. The fluid flow controller may also include a rotor having a first rotor blade and a second rotor blade radially spaced from the first rotor blade. The rotor may be configured to rotate relative to, and preferably within, the casing such that the casing blade passes between the first and second rotor blades during use. Compared to conventional pumps or compressors, the present fluid flow controller may have an enhanced ability to accelerate (and possibly to subsequently pressurize) fluid flow. Thus, the need to use multiple stages may be reduced or eliminated.

Abstract: A fluid flow controller and method of operation thereof are presented. The fluid flow controller may include a casing having a casing blade. The fluid flow controller may also include a rotor having a first rotor blade and a second rotor blade radially spaced from the first rotor blade. The rotor may be configured to rotate relative to, and preferably within, the casing such that the casing blade passes between the first and second rotor blades during use. Compared to conventional pumps or compressors, the present fluid flow controller may have an enhanced ability to accelerate (and possibly to subsequently pressurize) fluid flow. Thus, the need to use multiple stages may be reduced or eliminated.