Abstract: A single dielectric barrier aerodynamic plasma actuator apparatus based on the dielectric barrier discharge phenomenon is disclosed and suggested for application to aerodynamic uses for drag reduction, stall elimination and airfoil efficiency improvement. In the plasma actuator apparatus non-uniform in time and space, partially ionized gasses are generated by one or more electrode pairs each having one electrically encapsulated electrode and one air stream exposed electrode and energization by a high-voltage alternating current waveform. The influence of electrical waveform variation, electrode polarity, electrode size and electrode shape on the achieved plasma are considered along with theoretical verification of achieved results. Light output, generated thrust, ionizing current waveform and magnitude and other variables are considered. Misconceptions prevailing in the present day plasma generation art are addressed and are believed-to-be corrected.

Abstract: The present invention relates to apparatus for influencing fluid flow over a surface, and more particularly, but not exclusively, to turbulent boundary layer flow drag reduction for an aircraft. The present invention provides such apparatus including a plasma generator comprising first and second spaced-apart independently controllable electrodes operable to cause a change in direction of the flow of the fluid over the surface.

Abstract: The present invention provides a system and method for controlling leading edge contamination and crossflow instabilities for laminar flow on aircraft airfoils that is lightweight, low power, economical and reliable. Plasma surface discharges supply volumetric heating of the supersonic boundary layers to control the Poll Reynolds number and the cross flow Reynolds number and delay transition to turbulent flow associated with the leading edge contamination and crossflow instabilities. A closed-loop feedback control system that incorporates these principles includes three primary components: heat-flow sensors, a PID controller, and plasma discharge elements. Heat-flow sensors distributed around the airfoil surface provide root-mean-square (rms) pulsations of the heat flow to the airfoil skin.

Abstract: The present invention provides a system and method for controlling leading edge contamination and crossflow instabilities for laminar flow on aircraft airfoils that is lightweight, low power, economical and reliable. Plasma surface discharges supply volumetric heating of the supersonic boundary layers to control the Poll Reynolds number and the cross flow Reynolds number and delay transition to turbulent flow associated with the leading edge contamination and crossflow instabilities. A closed-loop feedback control system that incorporates these principles includes three primary components: heat-flow sensors, a PID controller, and plasma discharge elements. Heat-flow sensors distributed around the airfoil surface provide root-mean-square (rms) pulsations of the heat flow to the airfoil skin.

Abstract: The present invention relates to apparatus for influencing fluid flow over a surface, and more particularly, but not exclusively, to turbulent boundary layer flow drag reduction for an aircraft. The present invention provides such apparatus including a plasma generator comprising a first electrode (7) and a signal generator (18), the apparatus being operable to drive the first electrode (7) with a pulsed signal generated by the signal generator (18) thereby to cause a change in direction of the flow of the fluid over the surface.

Abstract: Method and apparatus for impingement on the sonic wave produced by a supersonic gas flow and the gas flow in a boundary layer of a gas that interfaces with a solid substrate comprising providing a source of a mixture of ions and electrons, introducing said ions and electrons into the region behind the sonic wave and ahead of the boundary layer, separating said ions and said electrons in said region maintaining a substantial portion of said ions proximate said region and maintaining a substantial portion of said electrons remote from said region.

Abstract: Improved methods and techniques for fabricating a panel of control cells, or a “control panel”, useful in various electromagnetic turbulence control (EMTC) applications includes a layered structure which includes three main components or layers: a metal substrate or backing plate having a high magnetic permeability; a ribbed magnetic structure attached to the metal substrate; and an electrode board bonded to the ribs of the magnetic structure. The ribbed magnetic structure is realized, in one embodiment, by a series of rare earth permanent magnets placed side-by-side using a bowed tool to create permanent magnet columns. The magnet columns thus formed are precisely positioned and glued to the substrate or backing plate so as to form parallel magnetic ribs. An electrode board, similar to a printed circuit board, is then bonded to the ribs of the magnet columns, e.g., so that a back side of such electrode board rests on top of the magnetic columns or ribs.

Abstract: Magnetic and electric fields are used in a controlled manner to create Lorentz forces that affect the flow of a conductive fluid near the boundary layer of a control tile, or a matrix of control tiles, immersed in a conductive fluid. The control tiles are combined to form control cells, with each control cell including a pair of electrodes and at least one permanent magnet. The pair of electrodes are coupled to a current source which biases the electrodes to cause an electrical current to flow from a positive electrode (anode), through the conductive fluid in which the cell electrodes are immersed, to a negative electrode (cathode). The current source is time multiplexed to better control the direction of the current flow between adjacent electrodes. The permanent magnet(s) generates a magnetic field which interacts with the electrical current to create a Lorentz force that influences the flow of the conductive fluid, near the boundary of the control tile, e.g.

Abstract: The boundary layer of a fluid travelling in a mean-flow direction relative to a surface of a wall of a body is controlled by generating in the fluid a magnetic field B having flux lines along the surface of the wall and an electric current density J traversing the magnetic flux lines in the fluid to form a control region. The magnetic field B and the electric current density J create in the control region a force J.times.B that introduces a vorticity distribution .omega. (x,y,z,t) into the flow. A plurality of such control regions is arranged in an two-dimensional array of control tiles that are actuated such that over the array the vorticity at the wall in the direction transverse to the free-stream direction is reduced and creation of the boundary layer vorticity concentrations in the free-stream direction is inhibited.

Abstract: An electro-magnetohydrodynamic (EMHD) transducer that detects and manipuls the velocity of a near-wall fluid below a turbulent boundary layer includes a magnetic field generator to provide a magnetic field near a surface exposed to the fluid. A pair of spaced electrodes are disposed within the magnetic field. A controller coupled to the electrodes detects the electric field induced by the motion of a conductive fluid relative to the surface. The controller selectively activates the electrodes to generate an applied electric field between the electrodes when the detected field exceeds a threshold. The Lorentz force generated in response to the applied electric field and the magnetic field either decelerates or accelerates the motion of the conductive fluid to prevent the formation of turbulent events.

Abstract: An air intake system disposable in an air vehicle turbo engine housing disposed in an exterior airflow for selectively reducing external engine boundary layer separation drag and external engine friction drag on the engine housing comprising an air inlet member for receiving engine intake air disposable within the engine housing. The air intake system further comprising a first air exit port disposed in fluid communication with the air inlet member, adapted to direct intake air from the air inlet member and to direct intake air substantially in the direction of exterior airflow, to reduce external engine boundary layer separation drag. The air intake system further comprising a second air exit port disposed in fluid communication with the air inlet member, adapted to direct intake air from the air inlet member and to direct intake air substantially in a direction perpendicular to the exterior airflow, to reduce external engine friction drag.

Abstract: A boundary layer control device for a surface which reduces turbulence by oviding forces which counteract microturbulent events occurring at the surface. The microturbulent events occur periodically with a known topography and include liftup and ejection, bursting, low-speed streak and sweep topography. The device has an array of magnet and electrode cells which are arranged to correspond with the topography arrangement of the microturbulent events. The interaction of the magnetic and electric fields within the cells generate a Lorentz force which can be directed into or out of the surface depending on the relative directions of the magnetic and electric fields. Sensors on the surface determine which cells to activate and in what direction to apply the Lorentz force to precisely counteract the microturbulent events occurring at the surface. A force directed away from the surface is used to counteract a sweep event and a force directed towards the surface counteracts a liftup event.

Abstract: A method for controlling microturbulence in a medium flowing near a surface s disclosed. The method includes the steps of measuring the forces acting near or on the surface and using those measurements to determine the state probabilities for the microturbulent events occurring at the surface. The control method then activates selective cells in an array of cells to apply forces at the surface to counteract the microturbulent events and thus reduce turbulence. Each cell has a pair of electrodes and opposing magnetic poles such that when the control method activates a cell, the interaction of the electric field and the magnetic field at the cell creates a Lorentz force normal to the surface.

Abstract: The system includes radiation generation and transmission components which radiate tuned microwave electromagnetic energy outwardly from a vehicle through an antenna into a fluid medium through which the vehicle is moving. The microwave radiation is at the frequency of harmonic resonance electromagnetic excitation of the molecules of the medium which produces efficient heating and ionizing of the fluid resulting in a reduction of the mass density thereof. This reduction decreases the drag forces acting on the vehicle resulting in a greatly enhanced aerodynamic and/or hydrodynamic efficiency and also decreases the intensity of the shock waves (which often lead to sonic booms). An aircraft's dramatically higher speed in the surrounding rarefied medium can make it appear to be travelling at "supersonic" speeds.

Abstract: A surface layer for use in connection with an object adapted for motion tugh a fluid includes an array of tiles each having a pair of electrodes and a pair of magnetic poles positioned to generate respective electric and magnetic fields generally transverse to each other. Either or both of the electrodes or magnetic poles are controllable to provide adjustable electrical and/or controllable magnetic fields. A plurality of turbulence sensors is provided each located proximate to and generally upstream of a tile. Each turbulence sensor generating a turbulence signal representative of fluid turbulence proximate thereto. A control circuit for controlling the electrical field generated by the electrodes and/or the magnetic field generated by the magnetic pole in relation to the turbulence signal from the turbulence sensors, thereby to generate a Lorentz force for controlling the fluid.

Abstract: Method and apparatus for covering a free-standing body with a uniform glow discharge plasma, particularly at atmospheric pressure. The method may be used to provide a body coated with such a plasma, and also to treat a workpiece.

Abstract: The boundary layer of a fluid travelling in a mean-flow direction relative to a surface of a wall of a body is controlled by generating in the fluid a magnetic field B having flux lines along the surface of the wall and an electric current density J traversing the magnetic flux lines in the fluid to form a control region. The magnetic field B and the electric current density J create in the control region a force J.times.B that can stabilize or destabilize flow in the boundary layer. A plurality of such control regions can be arranged in an two-dimensional array of control tiles that are periodically actuated in a controlled, predetermined pattern at a critical frequency that provides boundary layer control over a given area.

Abstract: The boundary layer of a fluid travelling in a mean-flow direction relative to a surface of a wall of a body is controlled by generating in a near-wall region of the flow a magnetic field B having flux lines parallel to the surface of the wall and an electric current density J traversing the magnetic flux lines in the fluid. An electrolyte or other conductivity-enhancing material is introduced into the flow to provide an electrical conductivity gradient in the near-wall region. The magnetic field B and the electric current density J create in the fluid a force J.times.B having a component normal to the surface of the wall that because of the increased conductivity gradient near the surface can stabilize or destabilize flow in the boundary layer. Numerous aspects of the fluid flow and its interaction with the body can thus be controlled.

Abstract: The Sonic Boom Attenuator is a device designed for use with supersonic aircraft wherein a laser beam is shone down the leading edge of a short, rigid, straight, thin wing, heating thus rarefying the air before it passes over and under the wing. In this manner, the compression (which results from the rarefication) occurs more slowly as the relative wind passes through the beam than it otherwise would by impact with the hard surface of the wing. Because of the simplicity of design there are fewer components than have been proposed by other inventions and fewer mechanical devices to fail. Because of the rarefication, there is an overall reduction in drag to the aircraft and an attenuation of sonic boom in supersonic flight.

Abstract: A nursing bottle holder comprising a shoulder strap having a Velcro pad disposed on the front vertical surface thereof and a bottle strap having a complimentary Velcro pad disposed on the outer surface thereof, the Velcro pads being temporarily engageable to hold the nursing bottle in a selected vertically planar position. The shoulder strap and bottle strap may also each be provided with Velcro strips on opposing ends and surfaces thereof, respectively for adjusting the shoulder strap about the body and the bottle strap about bottles of varying diameters.