Abstract: A three degrees-of freedom robotic flapper includes a fuselage, the fuselage housing motors and driving trains, a left wing attached to the fuselage, and a right wing attached to the fuselage, the left wing and the right wing configured to perform a wing flapping motion, a wing twisting motion and a wing folding motion.

Abstract: A free-streamline airfoil includes a front portion, the front portion including a leading edge geometry configured to force a sudden separation of the flow, and a contoured rear portion.

Abstract: A free-streamline airfoil includes a lower surface which is flat or contoured, and an upper surface that is curved or made of discrete flat elements approximating a curved surface, the upper surface presenting a cavity, a cavity width in an airfoil chordwise direction shorter than the airfoil chord, a position and depth of the cavity triggering a turbulent flow over the airfoil's suction side while preserving the airfoil physical integrity.

Abstract: A free-streamline airfoil includes a front portion, the front portion including a leading edge geometry configured to force a sudden separation of the flow, and a contoured

Abstract: The present invention provides a system for engaging a fluid flow. The system comprising one or more foil members operationally connected to a feedback control loop system. In one embodiment, the foil member is a hydrofoil member or an airfoil member. The foil members are configured for one or more degrees of freedom of oscillatory movement within the fluid flow. The feedback control loop system comprises a sensor system, actuator system, and a controller system. The feedback control loop system configured for actuating the foil members and thereby optimizing the operation of the foil members to attain one or more optimization objectives. In operation, the foil members are situated in the fluid flow and are manipulated to attain one or more optimization objectives.

Abstract: The present invention provides a system for engaging a fluid flow. The system comprising one or more foil members operationally connected to a feedback control loop system. In one embodiment, the foil member is a hydrofoil member or an airfoil member. The foil members are configured for one or more degrees of freedom of oscillatory movement within the fluid flow. The feedback control loop system comprises a sensor system, actuator system, and a controller system. The feedback control loop system configured for actuating the foil members and thereby optimizing the operation of the foil members to attain one or more optimization objectives. In operation, the foil members are situated in the fluid flow and are manipulated to attain one or more optimization objectives.

Abstract: The systems and methods of the invention include systems and techniques for controlling a turbulent boundary layer flow with a transverse traveling wave, oscillating at certain selected frequencies, amplitudes and wavelengths, to provide substantial reductions of drag. To this end, the systems and processes can include a boundary layer control system having an object with at least one surface exposed to a medium flowing over the surface. A plurality of excitation elements may be arranged on the surface and these elements are capable of exciting a traveling wave force field in a span-wise direction that is substantially parallel to the surface and perpendicular to direction of the flow. A first component of the traveling wave force field in the span-wise direction is substantially greater than a second component of the traveling wave force field, that is substantially perpendicular to the span-wise direction.

Abstract: The systems and methods of the invention include systems and techniques for controlling a turbulent boundary layer flow with a transverse traveling wave, oscillating at certain selected frequencies, amplitudes and wavelengths, to provide substantial reductions of drag. To this end, the systems and processes can include a boundary layer control system having an object with at least one surface exposed to a medium flowing over the surface. A plurality of excitation elements may be arranged on the surface and these elements are capable of exciting a traveling wave force field in a span-wise direction that is substantially parallel to the surface and perpendicular to direction of the flow. A first component of the traveling wave force field in the span-wise direction is substantially greater than a second component of the traveling wave force field, that is substantially perpendicular to the span-wise direction.