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 a means 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 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.

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.

In an embodiment, the present disclosure pertains to a cavitation generation device that includes a dactyl plunger rotatable about an axis between an open position and a closed position and a propus socket having a channel. The propus socket is rigidly mounted below the dactyl plunger, and the dactyl plunger is received into the propus socket when the dactyl plunger is in the closed position. The cavitation generation device can also include a torsion spring that biases the dactyl plunger into contact with the propus socket. In another embodiment, the present disclosure pertains to a method of inducing a cavitation including biasing a dactyl plunger via a torsion spring, and rotating the dactyl plunger, by action of the torsion spring, into a propus socket. The propus socket includes a nozzle-shaped channel. The method further includes ejecting a socket cavity volume through the nozzle-shaped channel thereby inducing a cavitation event.

A fluid device includes: a flow path through which a fluid flows; and an ultrasonic wave transmitter configured to transmit an ultrasonic wave to generate a standing wave to the fluid in the flow path along a first direction orthogonal to a flowing direction of the fluid. The ultrasonic wave transmitter is in contact with the fluid and faces an antinode region corresponding to any antinode in the standing wave.

A propulsion system coupled to a vehicle. The system includes a diffusing structure and a conduit portion configured to introduce to the diffusing structure through a passage a primary fluid produced by the vehicle. The passage is defined by a wall, and the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid. A constricting element is disposed adjacent the wall. An actuating apparatus is coupled to the constricting element and is configured to urge the constricting element toward the wall, thereby reducing the cross-sectional area of the passage.

Provided is an apparatus for removing thermal stratification generated by turbulent penetration by using a rotation ring. The apparatus removes thermal stratification formed in a branch pipe branching from a main pipe through which a high-temperature fluid flows, the apparatus including: a hollow body portion coupled to the branch pipe; a plurality of first electromagnets provided to be spaced apart from each other in a circumferential direction of the body portion; a controller configured to sequentially change polarities of the plurality of first electromagnets; and a rotation ring including a plurality of second electromagnets having either an N polarity or an S polarity, the rotation ring being rotatably coupled to the body portion, wherein, when the polarities of the plurality of first electromagnets are sequentially changed, the rotation ring rotates according to a magnetic force of the plurality of first electromagnets and the plurality of second electromagnets.

An aircraft is disclosed having a structure at least part of which is capable of generating aerodynamic lift. A body having a mass is movably mounted to a portion of the structure by an active support. The active support includes an actuator to move the body relative to the portion of the structure, and a controller for controlling movement of the actuator in response to a dynamic input. The active support provides a range of movement for the body in at least one degree of freedom. The actuator moves the body across the entire range of movement in that one degree of freedom in a time period of less than 3 seconds. The actuator moves the body sufficiently rapidly to generate an inertial force that is equal to or greater than any aerodynamic force generated by the body during that movement of the body. The active support may be used to reduce loads on the aircraft structure.

In an embodiment, the present disclosure pertains to a cavitation generation device that includes a dactyl plunger rotatable about an axis between an open position and a closed position and a propus socket having a channel. The propus socket is rigidly mounted below the dactyl plunger, and the dactyl plunger is received into the propus socket when the dactyl plunger is in the closed position. The cavitation generation device can also include a torsion spring that biases the dactyl plunger into contact with the propus socket. In another embodiment, the present disclosure pertains to a method of inducing a cavitation including biasing a dactyl plunger via a torsion spring, and rotating the dactyl plunger, by action of the torsion spring, into a propus socket. The propus socket includes a nozzle-shaped channel. The method further includes ejecting a socket cavity volume through the nozzle-shaped channel thereby inducing a cavitation event.

According to the present disclosure there is provided an arrangement for influencing liquid flow, the arrangement comprising: a first section selectively configurable to provide a vortex generator surface to induce vortices in the liquid flow. The arrangement further comprises a second section, wherein the first section and second section are movable relative to one another to provide the vortex generator surface.