A movable device includes: at least one lift generating unit for generating a pressure difference between opposite sides thereof to generate a lift force; a movable device body connected to the lift generating unit to be movable by means of the lift force generated by the lift generating unit; and at least one supply duct, the number of which corresponds to the number of the lift generating unit, wherein on end of the supply duct is disposed on one side of the lift generating unit and, when the lift generating unit operates, fluid is suctioned through the other end of the supply duct to be supplied into the lift generating unit.

An aircraft propulsion system utilizes a rotary engine to drive a centrifugal fan providing a thrust vector that is generally orthogonal to an axis of rotation of the rotary engine and the fan. The aircraft propulsion system may be mounted, for example, in the wing of a fixed-wing aircraft with the rotary engine and the centrifugal fan rotating about an axis of rotation that is generally parallel to a yaw axis of the aircraft.

A flow control apparatus includes a plasma actuator, a storage device, and a control circuit. The plasma actuator causes discharge in a discharge area by applying an alternating-current (AC) voltage between electrodes to form an induced flow of gas. The electrodes are shifted relatively to each other with a dielectric disposed between them. The storage device stores a changing condition of an AC voltage waveform for changing a gas flow state formed in a flow control area of gas from a first state to a second state by adding the induced flow of gas. The control circuit refers to the changing condition of the AC voltage waveform and control the AC voltage waveform based on the changing condition of the AC voltage waveform, in a case of changing the gas flow state formed in the gas flow control area from the first flow state to the second flow state.

A streamlined tailfin pivotably attached to a shaft-shaped member disposed on a vehicle provides for reduced drag in winds varying in direction impinging thereon.

A streamlined tailfin pivotably attached to a shaft-shaped member disposed on a vehicle provides for reduced drag in winds varying in direction impinging thereon.

An aircraft includes an airframe, a hollow member, and a plasma actuator. The hollow member has a body and an internal flow passage. The body extends from front of the airframe to rear of the airframe and has a hollow shape. The internal flow passage extends in the body from the front to the rear. The body has an introduction port configured to introduce a fluid into the internal flow passage, and a blow hole provided more toward the rear than the introduction port, and penetrating the body from an inner circumferential surface of the body to an outer circumferential surface of the body. The plasma actuator is provided at the outer circumferential surface of the body, and disposed on one or more sides, in a circumferential direction of the body, of the blow hole.

An arrangement for mechanically changing a surface includes an insulating layer, a pair of electrodes, which is arranged on or in the insulating layer, and a piezo element, which is arranged on or in the insulating layer. The piezo element is separated from the pair of electrodes by the insulating layer. The pair of electrodes is designed to generate in a region of the piezo element an electric field, which causes the piezo element to carry out a mechanical change of shape, in order in this way to mechanically change a surface of the arrangement. The pair of electrodes is also designed to generate the electric field such that the electric field has a minimum field strength in a surrounding area of the arrangement, in order in this way to generate a plasma in the surrounding area of the arrangement.

A fluid control system includes a dielectric-barrier discharge (DBD) device, and processing circuitry. The processing circuitry is configured to obtain a streamwise length scale of a fluid flowing over a surface. The processing circuitry is also configured to obtain a convective time scale of the fluid flowing over the surface. The processing circuitry is also configured to operate the DBD device, based on the streamwise length scale and the convective time scale, to adjust a flow property of the fluid.

An aircraft control system includes a flow control device and a control circuit. The flow control device is configured to control a flow of air around an aircraft. The control circuit is configured to control the flow control device so that a pressure distribution loaded on a surface of a structure that constitutes the aircraft is equal to a control value of a pressure distribution calculated based on a physical quantity detected by a sensor provided in the aircraft. The physical quantity relates to the air.

A flow control system includes a movable wing attachable to a wing of an aircraft, and a plasma actuator mountable on a surface of the movable wing. The flow control system is configured to control air flow around the wing by having the changing of the steering angle of the movable wing work in conjunction with the operation of the plasma actuator.