Abstract: An apparatus comprising: an aerodynamic surface adapted for producing an adverse pressure gradient in a fluid flow; and a first pulse detonation actuator disposed adjacent the aerodynamic surface and adapted for impulsively detonating a fuel/air mixture to produce a pressure rise and velocity increase of combustion products therein, the aerodynamic surface having a plurality of separation control holes adapted for communicating combustion product flows from the first pulse detonation actuator to the aerodynamic surface for modulating separation of the fluid flow from the aerodynamic surface.

Abstract: An aircraft designed with three wings located on either side of the fuselage. The forward wing has a downward angle with a curved top and bottom surface. The upper wing is located towards the rear of the aircraft and above the forward wing. The lower wing is located below the upper wing and slightly forward. It is also located to the rear and below of the forward wing. The outer ends of all three wings come into contact at one point. The forward wing uses the Coanda effect to increase the airflow across the top surface of the bottom wing. The aircraft can be designed so that it is large enough to carry people and/or cargo, or to be small enough to be flown as a toy aircraft. The like design can use any type of aircraft engine commonly used today. One embodiment of the aircraft has two turbines, shaft-coupled to a power source, located on either side of the forward end of the fuselage.

Abstract: A method and apparatus for active boundary layer control on an aerodynamic surface. One or more piezoelectric synthetic jet actuators operate as a boundary layer pump to ingest fluid along the surface of an aerodynamic object and discharge fluid tangentially to the fluid flow along the surface and/or at the trailing edge of the object to reduce drag and delay stall.

Abstract: A vehicle traveling through an environmental media such as air experiences drag. The drag is actively modulated by energy beams which may either increase or decrease the drag. The energy beams may provide either a chemical, acoustic or electromagnetic energy at a transition region between turbulent and laminar flows or at the leading edge of a laminar flow or in the direction of a crosswind in order to facilitate the respective increase or decrease in drag. If the vehicle is a sailing ship, areas of the sails are selectively roughened or widened to enhance the thrust derived from the wind. Furthermore, the keel or hull of the sailing ship may be modified to improve the hydrodynamic characteristics of the sailing ship. If the vehicle is an automobile, the tires or road surface may be selectively heated to improve the traction of the automobile.

Abstract: This light aircraft crash avoidance system performs what previous such systems perform, but with much less system weight, much less cost and much less expenditure of electrical energy. In this system, air enters openings or windows in front of concentric tubing and leaves through openings facing vertically downward, thus giving lift to an aircraft's wing, where needed. Unlike other designs, this one requires no high-pressure air tanks to provide high pressure, high-velocity air to air valves. The valves depend upon the forward motion of the aircraft to provide high velocity air and lift. Two different prime movers are suggested for rotating the outer tubing for opening or closing the air valve, one being a d.c. motor and the other a rotary solenoid, as the simpler one to implement. The proposed design is for making any needed corrections to the aircraft's roll angle and for providing buoyancy to the entire aircraft when making a landing.

Abstract: The Spark Jet can manipulate high-speed flows without moving aerodynamic structures and generates exhaust streams that can penetrate supersonic (as well as subsonic) boundary layers without the need for active mechanical components. The Spark Jet comprises a chamber with embedded electrodes and a discharging orifice. High-chamber pressure may be generated by rapidly heating the gas inside SparkJet using an electrical or other useful discharge. The pressure may be relieved by exhausting the heated air though an orifice.

Abstract: An apparatus comprising: an aerodynamic surface adapted for producing an adverse pressure gradient in a fluid flow; and a first pulse detonation actuator disposed adjacent the aerodynamic surface and adapted for impulsively detonating a fuel/air mixture to produce a pressure rise and velocity increase of combustion products therein, the aerodynamic surface having a plurality of separation control holes adapted for communicating combustion product flows from the first pulse detonation actuator to the aerodynamic surface for modulating separation of the fluid flow from the aerodynamic surface.

Abstract: Boundary layer control of a structural element in fluid stream is achieved by the following operations: providing in such structural element at least one region equipped with micro porous structure by an electroforming technique; having a fluid stream flow through the external surface of the at least one region, inwards or outwards with respect to the environment in which that element is placed.

Abstract: A process for the recovery of the energy from the air in pressurised areas of aircraft that involves linking or moving air from the pressurised areas to the lower areas of the fuselage or lower surfaces of the wings, the horizontal stabilisers, and other aerodynamic profiles, along ducting and/or by discharging through multiple slots or openings flowing downward and rearward with a small inclination against the direction of the air flow, to avoid turbulence. The pressure of the pressurised cabin air conditioning is used. In other cases, it is used the pressure produced at the front of the fuselage, on the leading edges of the wings, the horizontal stabiliser or other aerodynamic profiles. Lift is increased in all cases without further energy requirements.

Abstract: An apparatus comprising: an airfoil adapted for generating a lift force; and a first pulse detonation actuator disposed inside the airfoil and adapted for impulsively detonating a fuel/air mixture to produce a pressure rise and velocity increase of combustion products therein, the airfoil having a plurality of lift control holes adapted for communicating combustion product flows from the first pulse detonation actuator to an airfoil surface to modulate the lift force.

Abstract: Movable surface planes include opposed independently movable endless surfaces over the majority of opposite sides of the planes. By moving one surface in the same direction as the fluid flow about the plane, and the opposite surface in a direction opposite the fluid flow, the flow is accelerated across the surface moving in the same direction to produce a lesser pressure, and retarded across the surface moving in the opposite direction to produce a greater pressure. The net result is a force urging the plane toward the surface moving in the direction of ambient fluid flow. The two surfaces of the present invention may be operated independently of one another, to move in the same or opposite directions and to have the same or different velocities. The movable surfaces are porous and communicate with ductwork within the structure, to provide fluid flow through the surfaces for boundary layer control.

Abstract: A forebody 10 for an aeronautical vehicle 12 is provided. The forebody 10 includes an exterior wall 14 having a first half 16 and a second half 18. The first half 16 has a first porous section 20 and the second half 18 has a second porous section 24. The first half 16 and the second half 18 also have a first exterior side 22 experiencing a first fluidic pressure and a second exterior side 26 experiencing a second fluidic pressure, respectively. A hollow inner cavity 28 is fluidically coupled to the first exterior side 22 and the second exterior side 26 and allows fluid passage between the first exterior side 22 and the second exterior side 26 through the first porous section 20, the inner cavity 28, and the second porous section 24. The exterior wall 14 equalizes the first fluidic pressure with the second fluidic pressure. Additional forebodies and methods for performing the same are also provided.

Abstract: A system and method for providing an air curtain for impeding the entry of dust, dirt, debris, smoke, insects and other airborne particulate matter into an interior area of an aircraft without the need for disposing heavy, bulky and high power consuming blower assemblies above the opening in the aircraft. The invention comprises a pair of air intake ducts each having a fan disposed therein. The fans draw an ambient airflow into the air intake ducts. Pressurized air from a power unit associated with the aircraft, such as an engine or auxiliary power unit, is injected into the air intake ducts. This has the effect of significantly accelerating the airflow in the air intake ducts to a velocity suitable for forming an air curtain. The air intake ducts are coupled to a manifold having a length sufficient to substantially span the opening of an aircraft at which the air curtain is formed.

Abstract: The present invention involves a system for altering the aerodynamic shape and/or fluid flow about a solid body. The preferred embodiment comprises an obstruction disposed on the solid body and extending outwardly from the solid body into the fluid flowing over the solid body and a synthetic jet actuator embedded in the solid body such that said fluid flowing over the solid body encounters the obstruction before the synthetic jet actuator. The synthetic jet actuator includes a jet housing defined by walls, the jet housing having an internal chamber with a volume of fluid and an opening in the jet housing connecting the chamber to an external environment having the fluid, and a volume changing means for periodically changing the volume within the internal chamber so that a series of fluid vortices are generated and projected in the external environment out from the opening of the jet housing.

Abstract: Boundary layer control of a structural element in a fluid stream is achieved by the following operations: providing in such structural element at least one region equipped with micro porous structure by an electroforming technique; having a fluid stream flow through the external surface of the said at least one region, inwards or outwards with respect to the environment in which that element is placed.

Abstract: An aircraft weapons bay high frequency acoustic suppression apparatus is disclosed. The apparatus includes an extendable spoiler retractably received within an aircraft weapons bay. An injector unit is received within the spoiler for injecting high frequency pulses of pressurized gas into the airstream. The injector unit includes a resonance tube in outlet fluid communication with an nozzle. The pulsating output of the resonance tube perturbs the flow of pressurized gas in the nozzle, effectively breaking it up into discrete slugs or pulses which then exit the nozzle and enter the airstream. The high frequency perturbation of the airflow across the weapons bay, created by the aircraft weapons bay high frequency acoustic suppression apparatus of the present invention effectively suppresses undesirable acoustic resonance within the open weapons bay.

Abstract: This is an advanced simplified system for avoiding light aircraft crashes, using rate-of-turn sensors, solenoid-operated air valves and electrical circuits with relays. The sensors and air valves provide the needed corrections to an aircraft's pitch and roll angles to prevent it from going out of control. When needed, all valves blast out high velocity air to provide lift, thus preventing the aircraft from crashing upon landing. The system does not require air compressors and air tanks. In this simplified system, the inlets of the valves receive high velocity air from the aircraft's flight motion through the atmosphere. The more air valves installed on the wings of the aircraft the more lift produced. This system can continue to provide the needed lift and altitude corrections while the aircraft is in flight, the faster the flight, the greater the system's ability to make corrections, when needed, to avoid an aircraft crash.

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: An active control device for reducing high-speed impulsive (“HSI”) and blade vortex interaction (“BVI”) noise in a rotor aircraft, such as a helicopter, is disclosed. The system comprises a plurality of rotor blades extending radially in spaced relationship from a central hub, each of the blades having spaced apart upper and lower surfaces, an interior volume between the surfaces, and leading and trailing edges at the respective joined edges of the upper and lower surfaces. Air intake passages are disposed on the surfaces of each blade proximate the leading edge to controllably admit air into the interior volume; and air output passages are disposed on the surfaces of each blade proximate the trailing edge and the outer edge tip to controllably expel air from the interior volume of the blade. Admitting and expelling of air into and out of the interior volume of each blade is controlled in accordance with a determined condition of that blade.

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: Blades, including helicopter rotor blades, gas turbine engine fan blades, air moving machinery fan blades, and the like, have an air inlet near the hub of the blade, which may be on the pressure side of the blade and/or near the leading edge or trailing edge nearer the tip of the blades, with an air plenum between the air inlet and the slots, whereby air is forced into the inlet, through the plenum and out of the slots into the flow adjacent the blades. The slots may be through the suction surface of the blade, typically near the boundary layer separation point, so that air flowing out of the slots into the boundary layer of the suction surface of the blade, thereby delay or prevent the onset of boundary layer separation, or to reduce supersonic shock. The inlet may be near the trailing edge of the blade, near the root, adjacent to the air inlet of the core of a jet engine, to suction off air and reduce fan wake blockage at the core inlet.

Abstract: In accordance with the present invention, an aerodynamic turbo engine nacelle, disposable about an engine having an engine face, for mitigating boundary layer separation of intake airflow comprises an engine inlet. The engine inlet is provided with an interior surface and a curved portion. The curved portion having a leading edge. The geometry of the engine inlet is such that the ratio of the circular area defined by the diameter defined by the leading edge of the curved portion to the minimum circular area defined by the interior surface of the engine inlet is less than 1.33. The engine nacelle is further provided with a pressurized fluid injecting device for injecting pressurized fluid at the engine inlet in a direction generally parallel to intake airflow in response to sensed airflow conditions.

Abstract: A method and apparatus for controlling the blowing of compressed air from an aerodynamic structure such as an aircraft wing or helicopter rotor blade and thus controlling the aerodynamic properties of the wing comprises a narrow slot (13) in the upper surface 915) of the structure near its trailing edge (14). Inside the wing (12) is a chamber (23) that is connected to the narrow slot (13) in the wing surface (15). The chamber (23) houses a compressed air conduit (16) for supplying and holding compressed air. A passageway (25) connects the conduit (16) to the slot (13) in the upper surface (25) of the wing (12). The lower wall (27) of the passage (25) has a slit (32) allowing a shutter (31) to move selectively into the passage (25) and obstruct the flow of compressed air through the passageway (25). The shutter (31) is attached to a smart material actuator comprising a piezoelectrical bender (29). When a control voltage is applied to the bender (29), the bender (29) will bend.

Abstract: Vortical lift over a highly swept wing can be controlled by stabilizing or strengthening the major vortex by a small continuous jet of air, or a pulsating jet, near the core of the vortex. This method relies on the natural inductive action of the vortex swirling flow to entrain the injected air into the core of the vortex. When the additional momentum from the blowing air becomes aligned with the vortex mean flow direction, the vortex is stabilized and vortex breakdown is delayed.

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 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 aircraft having a wing with a top surface and a bottom surface, with the top surface having a first plurality of jets containing flow straighteners integrally hinged to the skin of the aircraft and positioned to direct air rearwardly along the top surface of the wing and the bottom surface having a second plurality of jets containing flow straighteners integrally hinged to the skin of the aircraft and positioned for directing air forwardly along the bottom surface of the wing and a compressor for receiving outside air and pressurizing the air which is then directed rearwardly along the top of the wing to decrease the pressure on top of the wing and forwardly along the bottom surface of the wing to increase the pressure on the bottom of the wing to increase the lift of the wing and thereby increase the lift and permit the aircraft to takeoff and land at a ground speed slower than if the pressurized air was not directed over the wing.

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: An apparatus for enhancing the steering effect of ship rudders comprising a rudder with at least one passageway for supplying seawater to ducts in the rudder, and a profile element extending substantially vertically at a leading edge of the rudder and being pivotable about a generally vertical axis, wherein distribution ducts formed between the profile element and the rudder communicate with the passageway and are adjustable so that relative movement of the profile element and the rudder causes seawater to be discharged along the rudder surface facing abaft.

Abstract: A lift apparatus using the method of blowing air over the upper surface of the apparatus to generate lift by virtue of the balance of outside pressures against the body of the apparatus. It does this by using the expansion characteristic of supersonic gas stream in a divergent space to create low pressure above the upper surface and to maintain the attachment of the stream to the surface. For power source, it uses the hybrid internal combustion engine of a co-pending invention in its jet operation mode to jet the air. And it solves the working substance supply problem by recycling.

Abstract: The aircraft air conditioning energy recovery device exploits the high level energy in relation to the exterior, in the air conditioning air flow required for renewal, and involves the placement of the aircraft outflow valve in a duct through which all the air flows the duct being arranged from the pressurized cabin to the inside of the engine inlet diffuser, through the pylon and in some cases through the wing, with the air-conditioning flow being fed back to the input air flow through multiple openings on the inside wall of the inlet diffuser. The openings or grooves run at a slight angle to the direction of flow to avoid turbulence. The air conditioning input may be introduced through hollow radial guide vanes attached at the front end to the vanes of the first stage of the low-pressure compressor and to the hollow vanes, open at the back, in the first stage or stages of the low-pressure compressor stator where the pressure is lower than that of the cabin air.

Abstract: In an aircraft (1) according to the invention the engine drives a blower and the compressed air is used to increase the lift of the wing (18) and the canard (22) using jet flap propulsion.The airfoil profile has maximum thickness just forward of the control surface device (12) which has large included trailing edge angle and large leading edge radius. The control surface device hinge (17) is positioned close to the mean line (19) of the plane, and air slots (10) in the plane are blowing the control surface device.

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: A nacelle having a porous structure is provided with laminar flow control and contamination protection. In region B suction through a composite layer is achieved by evacuating a chamber adjacent the inner surface of the nacelle to provide laminar flow control. At the leading edge of the nacelle a sintered metal sheet is attached to an inner surface of the composite layer to control the flow of a liquid over the leading edge of the nacelle. The liquid is contained in a chamber adjacent the sintered metal sheet which is defined by a backing sheet which has a series of depressions therein. Hot air fed through a perforated pipe impinges upon the backing sheet and the depressions transmit heat to the sintered metal sheet. The sintered metal sheet has good thermal conductivity and in turn heats the porous composite layer to prevent the formation of ice thereon.

Abstract: A system for facilitating the enhanced aerodynamic control of an aircraft having a fuselage including a forebody defining a frontal portion adapted to create a primary vortex under certain flight conditions and a rear portion. The control system comprises a contour discontinuity which is formed between the frontal and rear portions of the forebody. The contour discontinuity is sized and configured to create a secondary vortex under certain flight conditions. In addition to the contour discontinuity, the control system comprises a pressurized fluid injecting device which is disposed within the forebody of the fuselage adjacent the contour discontinuity. The pressurized fluid injecting device is used to selectively manipulate the secondary vortex to control the flight performance characteristics of the aircraft.

Abstract: A device for controlling pressure loading of a member caused by a fluid moving past the member or the member moving through a fluid. The device consists of a porous skin mounted over the solid surface of the member and separated from the solid surface by a plenum. Fluid from an area exerting high pressure on the member may enter the plenum through the porous surface and exit into an area exerting a lower pressure on the member, thus controlling pressure loading of the member. A transpirational control device controls the conditions within the plenum thus controlling the side force and yaw moment on the forebody.

Abstract: The boundary layer flow along the surface of an aircraft rudder assembly is controlled by suction applied through perforations primarily installed in the leading edge of the rudder assembly. The control is such that a laminar flow is enforced or at least such that any turbulent flow is displaced so that it begins downstream of the rudder assembly leading edge. Suction air chambers are arranged along the leading edge inside a nose box of the rudder assembly and these boxes are connected through air ducts and a valve system to an exhaust fan. The valve system and the exhaust fan are controlled by a central processing unit providing a flow controller for the suction in response to control signals produced from rated values and sensed actual valves to provide a uniform distribution of the suction along the leading edge of the rudder assembly. The suction system may be switched over to a de-icing mode by blowing warm air out through the perforations in a controlled manner.

Abstract: A pressurized porous surface near the leading edge of a rotorcraft blade, is designed to be used as an active control device which alleviates the aerodynamics of blade vortex interactions (BVI) and thus the impulsive BVI noise levels and signature. The pressurized porous surface can be actuated on an azimuth-dependent deployment schedule or actuated continuously. The pressurized porous surface is supplied with either positively pressurized air, negatively pressurized air, or a combination of both, when actuated. The pressurized porous surface targets the local blade aerodynamics, rather than the vortex strength or blade/vortex separation distance.

Abstract: A system and method for reducing skin friction of an object in relative motion to a fluid. A skin forming a boundary between the object and the fluid, the skin having holes through which micro-blowing of air is blown and a transmitting mechanism for transmitting air through the skin. The skin has an inner layer and an outer layer, the inner layer being a low permeable porous sheet, the outer layer being a plate having high aspect ratio high porosity, and small holes. The system may further include a suction apparatus for suctioning air from the outer layer. The method includes the steps of transmitting air through the inner layer and passing the air transmitted through the inner layer to the outer layer. The method may further include the step of bleeding air off the outer layer using the suction apparatus.

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 method and apparatus for controlling the blowing of compressed air from an aerodynamic structure such as an aircraft wing or helicopter rotor blade and thus controlling the aerodynamic properties of the wing comprises a narrow slot (13) in the upper surface (15) of the structure near its trailing edge (14). Inside the wing (12) is a chamber (23) that is connected to the narrow slot (13) in the wing surface (15). The chamber (23) houses a compressed air conduit (16) for supplying and holding compressed air. A passageway (25) connects the conduit (16) to the slot (13) in the upper surface (15) of the wing (12). The lower wall (27) of the passage (25) has a slit (32) allowing a shutter (31) to move selectively into the passage (25) and obstruct the flow of compressed air through the passageway (25). The shutter (31) is attached to a smart material actuator comprising a piezoelectrical bender (29). When a control voltage is applied to the bender (29), the bender (29) will bend.

Abstract: An improvement to boundary layer control system, including a transpiration panel (58) for transpiring suction air in a distributed manner, is provided. The transpiration panel (58) replaces the discharge nozzle of prior art flow control systems. The transpiration panel (58) is generally a rigid panel having a plurality of small holes (62) extending from an inner panel surface (56) to a smooth outer panel surface (54). The transpiration panel (58) is positioned flush with an external aircraft surface in a region where laminar flow control is not being attempted. Exemplary subsonic and supersonic boundary layer control systems including the transpiration panel (58) are provided. A preferred location of the transpiration panel (58) for the subsonic application is the underside of a wing (80), near the leading edge. A preferred location of the transpiration panel (58) for the supersonic application including on the upper surface of a wing (114) near the fuselage (118), in a turbulent wedge region.

Abstract: A vehicular lift wing having a Coanda edge perimeter, is provided with a zle slot formation from which fluid ejection is directed tangentially from the full Coanda edge perimeter during translation through an ambient fluid medium. Omnidirectional control means supplies pressurized fluid to the nozzle slot formation at different azimuthal locations along the Coanda edge perimeter for selectively controlled generation of dynamic forces exerted on the wing.

Abstract: An aerodynamic low drag structure (12) has a skin (18, 19, 20) which in movement of the structure (12) relative to a surrounding gaseous fluid medium produces at a flow control region of the skin (18) laminar flow in a boundary layer adjacent the skin. To improve boundary layer control, gaseous fluid is withdrawn from the boundary layer at the flow control region into a first inlet opening (21, 22, 23) in the skin (18) and is conveyed along a first fluid flow path (241, 242) within the structure (12) for discharge at a discharge opening (28) downstream of the first inlet opening (21, 22, 23). Gaseous fluid is withdrawn at a second inlet opening (26) in the skin (20) at a region of the skin subjected to gaseous fluid at ramming pressure and conveyed along a second fluid flow path (27, 242) within the structure to the discharge opening (28) or a further discharge opening.

Abstract: A noise suppression system for a jet engine, the system having a substrate formed of open cell material, a layer of microporous material covering at least a portion of one surface of the substrate, a layer of substantially non-porous material covering at least one portion of an opposite surface of the substrate, and a pressurized air source for providing pressurized air to the substrate. The substrate, the microporous material, and the non-porous material are configured to define an inner surface of an inlet for the jet engine. The pressurized air is communicated from the substrate, through the microporous material, and into the inlet so as to provide a layer of less turbulent airflow along the inner surface of the inlet, thus mitigating noise generation.

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.

Abstract: In a helicopter having a main rotor, a tail boom and a circulation control slot along one side of the tail boom, and a thruster which is selectively directable at either side or both sides of the rear end of the tail boom, anti-torque and yaw control are effected by generating separate air flow streams of different pressures by means of separate pressure means and conducting said separate air flow streams at said different pressures in separate passages to respectively the circulation control slot and to the thruster.

Abstract: A helicopter rotor seal for gas-driven helicopters wherein the rotor is rotatably driven by a compressed air jets at the tips of the rotors directed rearwardly with respect to rotor rotation. A non-rotatable mast extends vertically from the helicopter fuselage including a concentric bore for communication of compressed air therethrough. Positioned at the upper extremity of the mast, above the rotor blades, is a rotatable plenum for distributing compressed gas to the helicopter's respective rotor blades.

Abstract: The nacelle of the aircraft is purged and the sidewall of the vector nozzles of the gas turbine engine in the nacelle is cooled by utilizing the engine fan air to drive ejector pumps mounted in series flow relationship, a rectangular mixing zone and a diffuser with a rectangular cross section and a step in the exhaust nozzle gaspath. This results in minimizing the amount of fan air for driving the system and enhancing engine thrust and enhanced sidewall cooling because the temperature of the mixed air is lower than heretofore known systems.