A fluid machine includes a rotary blade, a casing configured to house the rotary blade therein, and an insulation coated conductor attached within a recess circumferentially provided in an inner circumference of the casing opposed to an outer end of the rotary blade, the insulation coated conductor including a conductive wire and an insulation material coating. The dielectric barrier discharge is generated between the insulation coated conductor and the outer end of the rotary blade by applying a pulse voltage between the conductive wire and the rotary blade, so as to prevent leakage of operative fluid through a tip clearance between the inner circumference of the casing and the outer end of the rotary blade.

Disclosed are methods and apparatuses for mitigating the formation of concentrated wake vortex structures generated from lifting or thrust-generating bodies and maneuvering control surfaces wherein the use of contour surface geometries promotes vortex-mixing of high and low flow fluids. The methods and apparatuses can be combined with various drag reduction techniques, such as the use of riblets of various types and/or compliant surfaces (passive and active). Such combinations form unique structures for various fluid dynamic control applications to suppress transiently growing forms of boundary layer disturbances in a manner that significantly improves performance and has improved control dynamics.

The present disclosure is directed towards electro-fluid transducers that may influence the flow of a fluid in and around a channel. In one such embodiment, a system comprises a first electrode at least partially encapsulated by a first dielectric; a second electrode at least partially encapsulated by a second dielectric, wherein a portion of a channel exists between the first dielectric and the second dielectric; a third electrode positioned in the channel; and a fourth electrode positioned in the channel, wherein the electrodes influence a flow of a fluid in the channel upon the electrodes being energized.

An apparatus comprises a surface that is configured to be exposed to a fluid stream and a cavity wall that forms at least a portion of a cavity. A first channel opening is formed in the surface, and a second channel opening is formed in the cavity wall. A channel extends from the first channel opening in the cavity wall to the second channel opening in the surface.

An article with controllable wettability includes a substrate and a layer of a composite material supported on the substrate. The layer has an exposed surface and the composite material includes particles that have controllable polarization embedded fully or partially in a matrix. A controller is operable to selectively apply a controlled variable activation energy to the layer. The controllable polarization of the particles varies responsive to the controlled variable activation energy such that a wettability of the exposed surface also varies responsive to the controlled variable activation energy.

An airflow adjusting apparatus to be provided in a vehicle includes a first airflow generator and a second airflow generator. The vehicle includes a front wheel and a rear wheel that are disposed in a vehicle longitudinal direction to be partly protruded from a bottom surface of a vehicle body of the vehicle downward in a vertical direction of the vehicle body. The first airflow generator is provided on the bottom surface of the vehicle body and behind the front wheel, and configured to generate a first airflow moving backward of the vehicle. The second airflow generator is provided on the bottom surface of the vehicle body and behind the first airflow generator, and configured to generate a second airflow that deflects, vehicle-widthwise inward, an airflow flowing in from a side on which the first airflow generator is disposed.

Embodiments of the invention relate to a method and apparatus for providing high thrust density plasma, and/or high control authority plasma. In specific embodiments, such high thrust density, and/or high control authority, plasma can be at or near atmospheric pressure. Embodiments pertain to a method and apparatus that use electron confinement via one or more magnetic fields, and/or one or more electric fields, in a manner to improve the ionization due to surface plasma actuators. Specific embodiments can improve ionization by several orders of magnitude. This improved ionization can result in a high electric field inside the sheath for the same applied voltage and can result in very high thrust.

A neutralization device that neutralizes static electricity on a portion of a vehicle exposed to outside. The neutralization device causes corona discharge according to a positive potential thereof. The neutralization device is attached to a surface exposed outwardly widthwise of the vehicle in at least one of an inner circumferential portion of a tire and a predetermined point of an outer surface of tire wheel.

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.

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.