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: A propeller having one or more blades eccentrically mounted to a shaft dynamically changes the blade pitch to produce free vortices in a fluid. For extracting energy from a moving fluid, the fluid flow acting on the blades rotates the propeller, while the pitch changes create a fluid flow pattern known as a von Karman vortex street. The resulting time averaged flow field distant from the propeller is a wake flow, and the energy of the fluid flow can be efficiently converted to rotation of a shaft driven device. For propulsion, applied shaft rotation and the dynamic pitch change in a fluid together create a flow pattern that is the inverse of the von Karman vortex street. For either energy extraction or propulsion, the propeller is particularly suited for low flow speeds, where the effects of low Reynolds number induced flow separation on blades may make other propellers inefficient.

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: 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.