An apparatus including a controllable fluid-contacting surface is provided. In another aspect, the present apparatus includes a flexible membrane and multiple actuators each having an output shaft or activation member coupled to a water-contacting membrane, with the shafts extending in a direction offset from the nominal outer surface of the membrane. A further aspect of the present apparatus includes an underwater vessel including a propulsion source, a flexible membrane having a water-contacting outer surface and an electronic controller including programmable software for actuating the actuators.

A lift control device actively controls the lift force on a lifting surface. The device has a protuberance near a trailing edge of its lifting surface, which causes flow to separate from the lifting surface, generating regions of low pressure and high pressure which combine to increase the lift force on the lifting surface. The device further includes an arrangement to keep the flow attached around the protuberance or to modify the position of the protuberance in response to a command from a central controller, so as to provide an active control of the lift between a maximum value and a minimum value.

A fluidic logic and actuator system for outputting a displacement having a fluidic logic circuitry layer including a fluidic control input and a plurality of fluidic latching memory units. At least some of the plurality of fluidic latching memory units are configured to perform combinatorial and sequential logic functions and output a fluid response. A fluid actuator layer is provided having a plurality of fluid actuators, wherein each of the plurality of fluid actuators being movable in response to the fluid response of a corresponding one of the plurality of fluidic latching memory units.

An assembly for arrangement to the surface of an aerodynamic profile comprises an array of actuators, which are designed as piezo actuators and plasma actuators.

An acoustic cavity tailored synthetic jet employs a body having a cavity with a wall including a taper from a first extent to an aperture. The cavity is configured to produce a matched acoustic resonance. A drive system has a piston engaged to the cavity at the first extent. The drive system and piston are configured for oscillatory motion inducing a synthetic jet at the aperture.

One embodiment is an apparatus including an airfoil-shaped body; and a chordwise variable vortex generation system associated with the airfoil-shaped body, the chordwise variable vortex generation system controlling a deployment of at least one vortex generator on a surface of the airfoil-shaped body, wherein the deployment of the at least one vortex generator is dependent on a current angle of attack of the airfoil-shaped body. In some embodiments, the chordwise variable vortex generation system includes an actuator for controlling a location of the deployment of the at least one vortex generator responsive to a control signal indicative of the current angle of attack of the airfoil-shaped body. In certain embodiments, the surface of the airfoil-shaped body is a top surface of the airfoil-shaped body. In some embodiments, the airfoil-shaped body is an aircraft wing.

Systems, methods and apparatuses are provided for the reduction of hydrodynamic frictional drag. These systems, methods and apparatuses can include a vessel surface having an external layer and a plurality of dimples, wherein the external layer comprises a hydrophilic material, and wherein each of the dimples includes an inner surface having a superhydrophobic coating. The dimples can be configured to maintain an air-water interface as one or more fluids flow over the vessel surface. In some embodiments, a pressure reservoir can be coupled with the dimples, and can include an acoustic speaker to vibrate the air-water interface.

A system includes a surface having a fluid flowing over the surface. The fluid includes a flow regime having a streamwise length scale greater than about 100 times and less than about 100,000 times , where is a viscous length scale of the flow regime, and a convective time scale greater than about 10 and less than about 10,000, where is a viscous time scale of the flow regime. The system includes a controller that causes at least one of motion the surface to modify fluid flow in the flow regime based on the streamwise length scale and the convective time scale or motion of the flow regime based on the streamwise length scale and the convective time scale.

A fluidic control system (1) for controlling a vehicle, which includes a controller (2) and a closed fluidic circuit. The circuit includes a pump (3) for pressurizing fluid in the circuit, valve means (40, 50, 60), an actuator (4, 5, 6) and a precharge accumulator (7). The valve means (40, 50, 60) is fluidly connected to the inlet and outlet of the pump (3) and the actuator (4, 6) is fluidly connected to the valve means (40, 50, 60) for selectively receiving pressurized fluid therefrom. The precharge accumulator (7) includes a movable member (73, FIG. 2) that describes a variable volume (71) fluidly connected to the circuit between the valve means (40, 50, 60) and the inlet of the pump (3). The system (1) also includes a sensor (70) for determining the position of the movable member (73) for estimating the quantity of fluid and/or detecting an abnormal pressure variation within the circuit.

A system includes a surface, an actuator, and a controller. The surface has a fluid flowing over the surface. The actuator is coupled to the surface to move the surface relative to the fluid. The controller causes the actuator to cause the surface to generate a surface wave that modifies drag in the fluid. The actuator can cause the surface to generate a Love wave.