Abstract: A projectile having a plurality of micro electromechanical (MEMS) devices disposed about the axis of flight for active control of the trajectory of the projectile. The MEMS devices each form an integral control surface/actuator. Control circuitry installed within the projectile housing includes both rotation and lateral acceleration sensors. Flap portions of the MEMS devices are extended into the air stream flowing over the projectile in response to the rate of rotation of the projectile, thereby forming a standing wave of flaps operable to impart a lateral force on the projectile. MEMS devices utilizing an electrostatically controllable rolling flap portion provide a large range of motion while consuming a small amount of power. The MEMS devices may be arranged in longitudinal strips along an ogive portion of the projectile. Packaging concepts for projectiles as small as a 30 caliber bullet are described.

Abstract: A jet actuator positioned within a hollow space in an aerodynamic structure for controlling the flow over an aerodynamic surface thereof includes a movable member linearly displaced by a voice coil mechanism and a flexible diaphragm defining a compression chamber open to the exterior of the aerodynamic surface through an orifice. Reciprocal displacement of the movable member changes the shape of the flexible diaphragm to alternately expel fluid (e.g., air) from and pull fluid into the compression chamber through the orifice. The movable member includes a pair of pistons joined by a cross element, one of the pistons being attached to the flexible diaphragm. In one embodiment, the flexible diaphragm comprises a bladder sealed around the orifice. The movable member is desirably made of composite material to reduce its inertia, and at least the piston attached to the flexible diaphragm may be stiffened with a composite laminate structure.

Abstract: Disclosed is a fluid vehicle having one or more vertical wings in contact with the fluid for generating a forward motion. This fluid vehicle also has a stabilizing torque system for generating jets transverse to the forward motion for the purpose of counterbalancing any capsizing effect. Preferably, the system is devised to generate up and down jets to the opposite ends of at least one horizontal wing.

Abstract: The systems and methods of the invention include systems and techniques for controlling a turbulent boundary layer flow with a transverse traveling wave, oscillating at certain selected frequencies, amplitudes and wavelengths, to provide substantial reductions of drag. To this end, the systems and processes can include a boundary layer control system having an object with at least one surface exposed to a medium flowing over the surface. A plurality of excitation elements may be arranged on the surface and these elements are capable of exciting a traveling wave force field in a span-wise direction that is substantially parallel to the surface and perpendicular to direction of the flow. A first component of the traveling wave force field in the span-wise direction is substantially greater than a second component of the traveling wave force field, that is substantially perpendicular to the span-wise direction.

Abstract: A controllable vortex generator for reducing aerodynamic drag when vortex generation is not desired. The vortex generator includes a fin having a fixed forward portion and an aft portion which is movable between deflected and undeflected positions. At least a portion of the fin is formed of a memory shape alloy. The fin is attached to a base mountable to a surface such as the wing skin of an aircraft. An electrical resistance heating element is bonded to the fin and a controllable source of electric power is connected to the element. When the fin is heated by the element to a temperature equal to or greater than the transformation temperature of the alloy, the movable portion of the fin will move from a deflected position to an undeflected position, thereby reducing drag caused by the vortex generator.

Abstract: The nozzle of an acoustic jet directs high momentum flux gas particles essentially tangentially into the boundary layer of the flow in a diffuser, an engine air inlet, a jet engine gas flow path or on the suction surface of an airfoil, the gas particles in the chamber of the tangential acoustic jet being replenished with approaching low momentum flux particles drawn from the gas flow in a direction normal to the surface, thereby to provide a net time-averaged flow of increased momentum flux particles to defer the onset of boundary layer separation and/or reduce the thickness of the boundary layer. The acoustic jet is driven by a gas pressure oscillation generator which may be a loudspeaker, a resonant solenoid piston, a cranked piston, or the like.

Abstract: An active noise suppression apparatus and method for reducing jet engine noise and buffeting. A plurality of resonant cavities are formed in a structural member disposed on or adjacent to a jet engine exhaust nozzle. Each resonant cavity opens toward an output slot. A compressed air chamber is used to supply a pressurized, supersonic jetstream airflow through the inlet port into the interior area of the resonant cavity. This causes a high frequency, pulsed, excitation airstream to be generated outwardly from the cavity, out of the output slot and into the developing shear layer of the exhaust airflow. This high frequency, pulsed, excitation airstream induces modifications in the shear layer, which leads to a major reduction in the noise and buffeting generated by the developing shear layer. In an alternative embodiment, the resonant cavities are formed within one wall of a slot, where the slot is disposed along the leading edge of a cavity of the aircraft.

Abstract: The present invention provides a system and method for actively manipulating and controlling aerodynamic or hydrodynamic fluid flow over a surface. More specifically, the present invention provides a system and method to control aerodynamic or hydrodynamic fluid flow behavior of a ducted fluid flow using very-small-scale effectors. The system and method for actively manipulating and controlling fluid flow over a surface includes the placement of arrays of very-small-scale effectors on ducted surfaces bounding the ducted fluid flow. These very-small-scale effectors actively manipulated the boundary layer manipulated to control the flow behavior of the ducted fluid flow and suppress or prevent flow separation within the primary fluid flow.

Abstract: A system is disclosed that applies non-linear signal processing methods derived from theories of information and non-linear oscillations (chaos) to control the turbulent boundary layer of marine vessels in order to reduce the drag to which the vessels encountered while moving in water. The system uses measurement probes mounted along the hull of a marine vessel to provide detection markers for increase or decrease in the drag based on a prescribed fluid (i.e., air) injection and flow rate in boundary layer. The invention utilizes a differential radius (DR) to determine the minimum entropy for a given flow rate in the boundary layer which defines the optimum condition used by the system for reducing drag.

Abstract: The systems and methods of the invention include systems and techniques for controlling a turbulent boundary layer flow with a transverse traveling wave, oscillating at certain selected frequencies, amplitudes and wavelengths, to provide substantial reductions of drag. To this end, the systems and processes can include a boundary layer control system having an object with at least one surface exposed to a medium flowing over the surface. A plurality of excitation elements may be arranged on the surface and these elements are capable of exciting a traveling wave force field in a span-wise direction that is substantially parallel to the surface and perpendicular to direction of the flow. A first component of the traveling wave force field in the span-wise direction is substantially greater than a second component of the traveling wave force field, that is substantially perpendicular to the span-wise direction.

Abstract: Method, apparatus and sensors for directly interfacing a pilot (1) with the aerodynamic state of the surfaces of an aircraft, in particular allowing the direct sensorization of the conditions of the aerodynamic surfaces during the flight. The pilot (1) wears one or several “data suits” (2), for example on the arm, on the trunk, on the face or on the hands. The information on the boundary layer state is detected by a plurality of sensors (3) located on the different aerodynamic surfaces. A body interface (4) comprising a console (5), a multi-channel conditioning unit (6) and a processor (7) for the data acquisition are connected to the data suit (2). The data suit uses tactile sensations to transmit to the pilot, data responsive to critical airflow conditions at the sensors (3). In an aircraft with many aerodynamic surfaces the pilot can detect directly any arising critical condition.

Abstract: A method for inhibiting dynamic stall of an airfoil by causing a fluid to flow out of at least one location on the airfoil. This location may be anywhere on the airfoil; but if the location is within one-quarter of the airfoil chord from the leading edge and the fluid flow has non-zero net mass flux, then the fluid flow is modulated at a frequency described by a Strouhal ratio greater than one.

Abstract: An active flaperon assembly for a wing includes a sheet of flexible material deployed near an intersection between a primary lift surface of a wing and the surface of a flap. The sheet is mechanically linked to the flap such that it is withdrawn from and extended into the air flow over the wing, the extent of projection varying as a function of the downward deflection of the flap. An actuator generates mechanical oscillations in the sheet.

Abstract: Porous surfaces on an aerodynamic structure driven with positive and negative pressures are used in an active control system for attenuating shock waves responsible for high-speed impulsive (HSI) noise. The control system includes an array of apertures in the outer skin of the structure providing fluid communication between the exterior flow stream and an interior volume of the structure. A movable diaphragm within the structure pushes air out of and pulls air in through the apertures under the action of a drive mechanism within the structure, thus creating oscillating air jets. The drive mechanism may be actuated by a controller based on information supplied by a sensor in the leading edge of the aerodynamic structure. The array of apertures may be spaced apart along the outer skin of the aerodynamic structure so as to span a distance of about 15% of the chord length. The oscillating airjets may be provided on multiple surfaces of the aerodynamic structure, including the upper and lower surfaces.

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: A wing in combination with a fuselage having a body which is elongated in the direction of flight, the wing having physical parameters [comprising a wing having a relatively unswept and sharp leading edge, smooth convex chordwise contour over a majority of its surface from the leading edge, and a thickness to chord ratio of about 2% or less as a spanwise average, beyond a spanwise distance from the fuselage centerline of not more than about C/2.beta. on each side of the body, where .beta.=.sqroot.M.sup.

Abstract: Arrays of microslats operating within the boundary layer of an aircraft wing or other surfaces are provided. The arrays consist of rows of microslats, staggered between rows, and shaped so that the trailing edge of the microslat is normal or perpendicular to the direction of expected reverse flow on the surface. For flow regions having directionally stable flow, the microslats are rectangular. Where the direction of the expected reverse flow is variable, the trailing edge of the microslats is triangular, thereby accepting an angular range of reverse flow. Each microslat operates independently through a hinge on its leading edge and an individual spring which holds the microslat flush to the aerodynamic surface until actuated by reverse flow. Where the boundary layer is expected to thicken, i.e., downstream along a surface, the arrays are formed with two layers of microslats, smaller microslats in a top layer and larger in a bottom layer.

Abstract: The present invention relates to the field of aerohydrodynamics and heat and mass transfer and especially relates to a method and an apparatus for controlling the boundary layer or the wall layer of a continuous medium consisting of gases, liquids and/or their mixtures in the vicinity of a surface (1) for changing the flow structure, turbulence level, transfer of the impulse, transfer of heat and/or admixtures by influencing of the flow and changing of the velocities of the continuous medium particles.

Abstract: A leading edge structure of an aircraft airfoil including an outer skin, a front wall extended in the spanwise direction of the leading edge structure in a front section of the space defined by the outer skin so as to form an anti-icing duct together with a front part of the outer skin, and a plurality of ribs disposed in the space defined by the outer skin so as to form hot air passages. A laminar structure is formed by superposing upper and lower sheets of a superplastic titanium alloy, inserting a pair of core sheets of a superplastic titanium alloy between the upper and the lower sheet, and forming release agent layers in predetermined regions between the sheets.

Abstract: A boundary layer control apparatus including a duct having a streamlined shape which is mounted in spaced apart relation upwind from the wing and extending generally parallel to the leading edge of the wing. The duct has a thickness substantially less than the thickness of the wing to which it is attached. The duct of the present invention includes an opening on the downwind side of the duct for injecting compressed air toward a stagnation line associated with the aircraft wing. The duct according to the present invention can be pivoted during flight so that the air injected from the duct is always directed at the stagnation line, which moves relative to the aircraft wing as aircraft speed increases.

Abstract: An acoustic jet disposed within an aerodynamic surface, such as a wing or a blade, has a resilient wall supporting a mass. Vibrations of the blade cause oscillatory pressure waves within the acoustic jet, the nozzle of which directs fluid particles having high momentum flux essentially tangentially into the boundary layer of the suction surface of the blade, the resonant cavity of the synthetic jet being replenished with particles having low momentum flux drawn from the flow in a direction normal to the surface, thereby to provide a net time averaged flow of fluid particles of increasing momentum flux into the boundary layer to defer or prevent the onset of boundary layer separation. Single and double chambers drive nozzles separated streamwise or spanwise on airfoils (blades, wings) and fuselages. Applications include helicopters, airplanes, air moving machines and wind energy electric power generators.

Abstract: A deployable flow control device for a flow surface over which fluid having a fluid boundary layer flows which fluid boundary layer exhibits certain dynamics is disclosed. The deployable flow control device comprises a flow effector which is movably attached to a housing which is attachable, either initially or retrofitably, to a flow surface. The flow effector can position in a modular sub-housing removably attachable to the housing. The flow effector is deployed into and retracted out of the boundary layer on the flow surface and thereby controls the boundary layer dynamics. Devices (including devices utilizing a sealable, flexible element) operably connect to the flow effector and deploy and retract it. The sealable, flexible element has two elastic states defined as quiescent and deformed such that, when the sealable, flexible element is utilized, the flow effector is deployed into and retracted out of the fluid boundary layer based upon the elastic state of the sealable, flexible element.

Abstract: An active control system for reducing blade-vortex-interaction (BVI) noise generated by a rotor blade. The active control system includes a pressure sensor assembly, a device for changing a lift generated by the rotor blade, and a controller for activating the device upon a detected change in air pressure by the sensor assembly. The sensor assembly is disposed in close proximity to the rotor blade, and is adapted to detect a change in air pressure on a surface of the rotor blade near a leading edge of the rotor blade. The device is adapted to be activated by the controller, to thereby change a lift of the rotor blade. The controller activates the device to change a lift of the rotor blade in order to introduce a compensating pressure onto the surface of the rotor blade. This compensating pressure attenuates the magnitude of the change of air pressure.

Abstract: A surface for contact with a fluid, flowing in a flow direction (A) over the surface, is provided with grooves (1) to prevent flow separations at low, local Reynolds numbers. The grooves extend between an upstream-directed, closed groove entrance and a downstream-directed, open groove exit and are inclined to the flow direction (A), at least in the vicinity of the groove entrance.

Abstract: A passive porosity management device and process for an airfoil which provides a mechanism and method for controlling and modifying the lift, drag and flow field characteristics on an airfoil through the controlled seepage and transference of air utilizing passive porosity through one or more regions of an airfoil and into, and out of, one or more plenum cavities disposed in the interior portion of the airfoil.

Abstract: A vehicular boundary layer control system utilizing a series of external perforation arrays and suction sources controlled by a digital signal processor or microprocessor. Each array of perforations in the outer vehicle skin is served by a plenum chamber, which is selectively isolable from a suction manifold. The desired vacuum for each individual plenum and associated array is determined through the sampling of the turbulence associated with that array as well as other sensed environmental parameters. Vacuum is maintained at the desired level in each plenum through the arbitration of various suction sources and the selective restriction of airflow from the plenum(s) to the suction manifold. For terrestrial aerodynamic vehicles, a series of moisture separators are included in the plenums to mitigate the effects of any ingested moisture.

Abstract: Magnetic and electric fields are used in a controlled manner to create equal and oppositely-directed Lorentz forces tangential to the surface of a control tile that affect the flow of a conductive fluid near the boundary layer of the 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 may be time multiplexed to better control the direction of the current flow between adjacent electrodes.

Abstract: This invention relates to a system and method for reducing the primary vortex wake structure generated by a lifting body mounted on an object moving through a fluid. This is achieved by first, altering the generated initial vortex wake to make it vulnerable to rapid breakup; and, second, producing disturbances to this wake with secondary vortices from auxiliary lifting surfaces, called vortex leveraging tabs, to instigate this breakup. This invention relates to various fields of uses to include vortices generated by any type of lifting body moving through a fluid to include aircraft and watercraft, such as surface vessels and submarines.

Abstract: A method and apparatus using localized heating to encourage laminar flow along an airfoil exterior surface. The airfoil includes a leading edge (24), a controlled surface (18), and an uncontrolled surface (20). The present invention localized heating system (38) includes a heat source (40) located within the airfoil and connected to the leading edge (24), and a heat sink (42) positioned aft of the heat source (40) and arranged to transfer heat from the airfoil controlled surface (18) to the uncontrolled surface (20). The heat sink (42) preferably expels heat along uncontrolled surface adjacent to turbulent air flow. In one preferred embodiment as applied to a generally circular aircraft engine nacelle (12), the heat source (40) is an electro-thermal heat source (44) having a high resistance wire embedded in a composite material leading edge structure (50), and the heat sink (42) is a heat pipe (52) having a wicking material (58) and a vaporizing agent (60).

Abstract: An apparatus is described for producing fluidic jet perturbations for controlling a fluid stream and mix of fluids. The invention is especially applicable to aerodynamic bodies for delaying separation and increasing the maximum angle of attack. The teachings of the invention can easily be converted to produce mechanic or mechanical fluidic effects. The apparatus provides simultaneous perturbations applicable for successive perturbations in the longitudinal direction as well as for segmented requirements. However, the invention may be advantageously used in other applications, such as increasing the angle of divergence in diffusers, controlling and increasing the mixing rate of fluids in the mixing process without adding any mass, and vectoring fluid streams. It can also be applied, among others uses, for a windshield defogger or a vortex generator.

Abstract: A new method for boundary layer energization and boundary layer propulsion or use on vehicles moving through fluids, which comprises mounting small airfoils parallel or perpendicular to the vehicle's surface, said airfoils being embedded within the said vehicle's boundary layer and juxtaposed the surface of said vehicle, said airfoils being approximately the height of the boundary layer thickness and exciting said airfoils into flapping oscillation parallel to the chord plane of said airfoils, said oscillation at a frequency up to 100 cycles per second at an amplitude up to 20 percent of the chord length of said airfoil, whereby flow separation is delayed or suppressed which enables the redesign of said vehicle.

Abstract: A passive transpiration system for controlling interaction between turbulent boundary layer air and an impinging shock during supersonic airflow by application of a panel including passively activated mesoflaps that direct air circulation through a cavity in response to supersonic airflow. The mesoscopic flaps are preferably arranged in a matrix on one side of a cavity. The flaps deflect to allow air to circulate through the cavity during supersonic airflow, thus controlling the interaction between boundary layer air and air from the impinging shockwave. The flaps open to varying degrees depending on the speed of the airflow. The preferred structure includes channel sidewalls arranged parallel to one another and open on one end, creating multiple cavities. The sidewalls are connected by struts. Rows of flap support beams are connected to the sidewalls. The flaps are connected on one end to the beams, enabling them to deflect over their remainder in response to aerodynamic pressures.

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: A system to detect and control steady and unsteady boundary layer separation is provided. The system uses an array of transducers under a flexible wall over which the flow occurs. The system operates in two modes: a sensor mode and an actuator mode. In the sensor mode, transducers in the array are used as sensors to obtain a flow-induced wall pressure fluctuation signal characteristic to the incipient separation process. A controller uses the spatial location and frequency content of the sensed signals to determine the location and frequency of excitation needed to delay or defer the flow separation. In the actuator mode, transducers selected by the controller are excited at the aforementioned frequencies, typically immediately upstream of the separation point. This reattaches a separated flow or arrests the progression of separation from its incipient stages.

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 active control device for use on an aerodynamic structure is provided. The aerodynamic structure includes an outer aerodynamic skin and an interior volume, wherein the outer aerodynamic skin surrounds the interior volume. The active control device includes at least one aperture disposed on the outer aerodynamic skin and a diaphragm disposed in the interior volume of the aerodynamic structure. The at least one aperture connects the outer aerodynamic skin to the interior volume, and the diaphragm in the interior volume is movable between a first position and a second position. Movement of the diaphragm from the first position to the second position pushes air through the at least one aperture and out of the interior volume. Movement of the diaphragm from the second position to the first position draws air through the at least one aperture and into the interior volume. The diaphragm may be circular, or may be oval-shaped.

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 of disrupting a turbulent region of a boundary layer within a fluid flow passing over a surface to decrease momentum transfer, and thus friction drag, between the turbulent flow and the surface. Bending waves are generated on the surface to impose velocity and/or pressure oscillations within the turbulent region and disrupt the normal turbulent process within the boundary layer, thereby decreasing the transfer of momentum from the turbulent flow to the surface. The bending waves are preferably generated in a predominantly spanwise or normal direction relative to the streamwise fluid flow. In another embodiment, the bending waves enhance the turbulent process and increase the transfer of momentum between the turbulent flow and the surface. Bending wave actuators may bend the surface to generate bending waves within the surface itself. In another embodiment, actuators may generate bending waves within a separate material attached to the surface.

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: A method is provided for hypersonic laminar flow control which uses the effect of boundary layer stabilization by an ultrasonically transparent coating. A hypersonic body surface is covered by the coating which absorbs the flow disturbance energy and does not trip the boundary layer flow. In one embodiment, the coating is made from a porous material of regular structure containing cylindrical blind microholes normal to the body surface. In another embodiment, the porous material has random distributions of pore shape and orientation. Extraction of the flow disturbance energy by pores causes stabilization of the boundary layer on the coated surface and leads to laminar-turbulent transition delay. The method can be used to decrease the aerodynamic drag of hypersonic vehicles and reduce heat transfer on vehicle surfaces.

Abstract: The invention relates to a surface of a body exposed to circumfluent fluid with elevations protruding from the base surface.In order to design the surface of a body exposed to circumfluent fluid with elevations protruding from the base service with an even more favorable flow, it is provided that when the surface is viewed from the top the elevations are bordered in each case by two boundary lines of which the one boundary line is longer and possesses a greater curvature than the other boundary line so that the cross-section area of an airfoil is produced.

Abstract: The present invention is a laminar supersonic transport aircraft having a reverse delta wing located between a forward section and a distal end of the aircraft, a set of jet engines superposed on another set of jet engines, a stabilizing vertical tail located near the distal end of the aircraft, a stabilizing canard surface located near the forward section of said aircraft. Also, a laminar flow control device can be incorporated within the wing. The reverse delta aerodynamic wing has a basic reverse delta wing portion bounded by a leading edge and by a pair of trailing edges extending from respective ends of the leading edge toward a trailing apex point and respective span-wise wing extensions in a natural laminar boundary layer wing region extending chordwise from the leading edge by a fraction of the chordlength of the wing and extending span-wise from opposing sides of said wing.

Abstract: A passive porosity airfoil lift management device employed on a leading edge region of said airfoil whereby the lift on said airfoil may be varied and controlled by passively transferring air pressure between the upper surface and lower surfaces of said leading edge region of the airfoil through upper and lower porous skin regions, upper and lower plenum cavities disposed in said airfoil, and controllably monitoring and regulating said passive air pressure transference with at least one valve and a microprocessor.

Abstract: An apparatus, and its accompanying method, for reducing the drag of flows over a surface includes arrays of small disks and sensors. The arrays are embedded in the surface and may extend above, or be depressed below, the surface, provided they remain hydraulically smooth either when operating or when inactive. The disks are arranged in arrays of various shapes, and spaced according to the cruising speed of the vehicle on which the arrays are installed. For drag reduction at speeds of the order of 30 meters/second, preferred embodiments include disks that are 0.2 millimeter in diameter and spaced 0.4 millimeter apart. For drag reduction at speeds of the order of 300 meters/second, preferred embodiments include disks that are 0.045 millimeter in diameter and spaced 0.09 millimeter apart. Smaller and larger dimensions for diameter and spacing are also possible. The disks rotate in the plane of the surface, with their rotation axis substantially perpendicular 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: The method for damping global flow oscillations (20a.x, 20b.x) in a flowing medium in the region of an unstable flow (10) separating itself from at least one boundary surface (11, 12) is comprised of detecting the global flow oscillations with a sensor system (13) and superimposing a compensatory oscillation (15, 16) controlled by the signals of the sensor system onto the flowing medium in a separation zone of the separated unstable flow. Correspondingly, the apparatus for performing the method comprises a generator (17, 18) which superimposes a compensatory oscillation on the flowing medium in a separation zone of the separated unstable flow and a control system (28, 29) which evaluates the signals of the sensor system and controls the compensatory oscillation so that the amplitude of the global flow oscillation is damped by a prespecified factor.

Abstract: A fluid flow control device, comprising a flow surface over which a fluid flows, a flow effect means located on the flow surface and operated by pressure such that the flow effect means improves the flow characteristics of the flow surface, pressure supply means to operate the flow effect means and at least one microelectromechanical system ("MEMS") valve means which controls the flow effect means by controlling the supply of pressure to the flow effect means from the pressure supply means.

Abstract: An aircraft propulsive power unit having an engine (20), a nacelle structure (12) which houses the engine (20) and which has an exterior low drag boundary surface (16) which is subjected to exterior air flow in a boundary layer adjacent the boundary surface (16) and an air flow disruption device (19) activatable to cause at a control location in the boundary surface disruption of exterior air flow in the boundary layer at the control location without reversal or deflection of engine thrust gaseous flow. Where the power unit is a turbofan and the nacelle structure includes a fan duct (22) with inner and outer fan duct walls (25,26) the air flow disruption device (19) is additionally or alternatively activatable to cause at a control location in the outer fan duct wall (26) disruption of air flow in the boundary layer at the control location.

Abstract: An apparatus and method of stabilizing unstable shock waves on the surface of a body induce shock waves to form prematurely at a particular location on a surface of the body and fix that location such that shock waves will form consistently and persistently at that location on the surface of the body. Boundary layer flow separates from the surface of the body at that location and can be prevented from reattaching to the surface. Shock wave oscillations due to interactions with the separated boundary layer flow are prevented, thereby minimizing vibrations induced in the body. The apparatus has a flow accelerating surface and a discontinuity in the accelerating surface. The accelerating surface causes local fluid flow over the surface of the body to accelerate and prematurely and consistently form a shock wave at the point where the discontinuity is located.

Abstract: This invention outlines excitation means to transform the linear momentum of an underwing energized jet into rotational form in a selective manner to provide an asymmetric shear layer to increase compression wave reflection from the forward undersurface of a supersonic wing. The wing compression energy is thereby recovered into useful work as an increase in pressure on the upward reflexed wing backside. The upper surface of the shear layer is comprised of an array of vortices whose rotation is opposite to the wing circulation, providing the required angular momentum reaction. The upper wing surface is flat to avoid generation of waves and an adverse angular momentum reaction above the wing. The vortices below the wing are compressed by the underwing pressure, comprising a pressure shield to enhance the reflection.