Abstract: Systems and methods for providing dynamic control to a surface immersed in a dynamic fluid. The systems and methods of the invention relate to one or more morphable surfaces that can be control in an active manner to provide asperities that interact with a fluid moving across the morphable surfaces. By controlling the size, shape and location of the asperities, one can exert control authority over the motion of the surface relative to the fluid. Examples of materials that provide suitable morphable surfaces include ionic polymer metal composites and shape memory polymers, both of which types of material are commercially available. Useful morphable surface systems have been examined and are described.

Abstract: An arrangement of devices as well as a method for improving the aerodynamics of an aircraft wing are disclosed. In embodiments, a plurality of vortex generators are attached in span-wise alignment on an deice boot along the wing's leading edge. The vortex generators are, in embodiments, constructed of a flexible material such that they are able to be expanded along with the boot during inflation and deflation thus mechanically involving the aerodynamic devices in the ice-shedding process.

Abstract: The present invention features a fluid flow regulator that functions to significantly influence fluid flow across the surface of an object, as well as to significantly effect the performance of the object subjected to the fluid. The fluid flow regulator comprises a pressure recovery drop that induces a sudden drop in pressure at an optimal pressure recovery point on said surface, such that a sub-atmospheric barrier is created that serves as a cushion between the molecules in the fluid and the molecules at the object's surface. More specifically, the present invention fluid flow regulator functions to significantly regulate the pressure gradients that exist along the surface of an object subject to fluid flow. Regulation of pressure gradients is accomplished by selectively reducing the pressure drag at various locations along the surface, as well as the pressure drag induced forward and aft of the object, via the pressure recovery drop.

Abstract: An aircraft with a fluid-duct system for extraction of the laminar layer and/or blowing out of fluid at vulnerable places of the outer skin, wherein the fluid-duct system (26, 19, 18) by means of switchable valves (6, 4) is connectable to a pump facility (3), which is driven by the exhaust air from the cabin for generating a reduced pressure for the extraction of the laminar layer.

Abstract: Systems and methods for providing dynamic control to a vehicle in a dynamic fluid. The systems and methods of the invention relate to one or more morphable surfaces that can be controlled by a controller and an actuator in an active manner to provide asperities that interact with a fluid moving across the morphable surfaces. By controlling the size, shape and location of the asperities, one can exert control authority over the motion of the vehicle relative to the fluid, including a speed, a direction and an attitude of the vehicle. Examples of materials that provide suitable morphable surfaces include ionic polymer metal composites and shape memory polymers, both of which types of material are commercially available. Useful morphable surface systems have been examined and are described.

Abstract: An aircraft comprises first and second wings positioned on opposite sides of a longitudinal axis with each of the first and second wings including an upper surface and a lower surface, wherein no control surfaces are attached to the lower surface of the wings. A first forward opening control surface is attached by a first hinge to an upper surface of the first wing and a second forward opening control surface being attached by a second hinge to an upper surface of the second wing. Each of the first and second hinges is canted with respect to a direction perpendicular to the longitudinal axis. A method of yaw control performed by the aircraft is also included.

Abstract: A system for reducing aerodynamic noise of a supplementary wing of an aircraft is provided. The supplementary wing is hinged to a main wing and is extendable when a gap region between the main wing and the supplementary wing is opened. The system includes a separating surface which can be moved into the gap region when the supplementary wing is extended and which extends at least partially along a separation flow line between a vortex flow region and a gap flow for the air flowing in the gap region. The separating surface is an n-stable surface which through an actuator device can be moved between at least one of the stable states and at least one additional state.

Abstract: Improved miniature trailing edge effectors for aerodynamic control are provided. Three types of devices having aerodynamic housings integrated to the trailing edge of an aerodynamic shape are presented, which vary in details of how the control surface can move. A bucket type device has a control surface which is the back part of a C-shaped member having two arms connected by the back section. The C-shaped section is attached to a housing at the ends of the arms, and is rotatable about an axis parallel to the wing trailing edge to provide up, down and neutral states. A flip-up type device has a control surface which rotates about an axis parallel to the wing trailing edge to provide up, down, neutral and brake states. A rotating type device has a control surface which rotates about an axis parallel to the chord line to provide up, down and neutral states.

Abstract: The present invention is directed to a distributed active flow control (“DAFC”) system that maintains attached airflow over a highly cambered airfoil employed by an aircraft or other similar applications. The DAFC system includes a primary power source comprised of one or more aircraft engines, one or more power conversion units, and optionally, one or more auxiliary power units. The power conversion units are coupled to one or more aircraft engines for supplying power to a distribution network. The distribution network disperses power from the one or more power conversion units to active flow control units disposed within one or more aircraft flight control surfaces (e.g., the aircraft wing, the tail, the flaps, the slats, the ailerons, and the like). In one embodiment, an auxiliary power unit is included for providing a redundant and auxiliary power supply to the distribution network.

Abstract: A system and method is described generally for deforming a first surface of a body and deforming a second surface of a body to alter a fluid flow in order to change the characteristics of the fluid flow about the body and thereby control the fluid dynamic forces on the body.

Abstract: In order to achieve greater operational efficiency a propulsive arrangement is provided in which a relatively large number of small propulsive assemblies 9; 31, 32, 33 are provided in aircraft structures in particular the wing 7; 30. The assemblies 9; 31, 32, 33 comprise a flow path within which a compressor 39, 43, 47 is positioned to propel an air flow for propulsion. The compressors 39, 43, 47 are powered by electricity from an electricity generator 8 and possibly supplemented by solar cells or fuel cells or wing tip turbine generators 11. The assemblies 9, 31, 32, 33 are small to allow easy removal for maintenance and repair.

Abstract: The present invention relates to a flow control device and more particularly to reactive self-contained modular flow control device with deployable flow effectors. The present invention further relates to a method of operating the flow control device. One embodiment of the present invention includes a method of controlling air flow across a surface of an aircraft under certain flight conditions comprising the steps of sensing fluid separation from the surface by measuring the pressure on the surface; determining a standard deviation of the pressure measurements over a period of time; and deploying a flow effector in response to the standard deviation of the pressure measurements exceeding a predetermined threshold number.

Abstract: A device and method for conversion of the energy of medium flows are provided. The proposed device and method ensure suppression of the vortex streams in the flow on the leg of its motion along the radially converging trajectories and concentration of the flow energy, which is expressed by the increase of its velocity and decrease of the summary area of the cross section of the converging trajectories. As the flow runs along the first system of helical trajectories the following takes place: the harmful secondary vortex jets continue attenuating, the degree of concentration of the flow energy increases and velocity components form in the flow, which correspond to natural vortex streams, for instance, tornadoes, whirlpools.

Abstract: A spoiler and wing of an aircraft. A bottom surface of the spoiler has several longitudinal, elongated grooves. At least some of the grooves are equipped with one or more vortex generators. Further, the invention relates to a wing having in its back part at least one flap and having at least one spoiler of the invention arranged on the section between the wing and flap. The invention also relates to a method and control surface for generating vortexes.

Abstract: A method for analyzing performance of an airfoil includes determining: an estimated laminar separation location; a freestream turbulence intensity; a momentum thickness; and a turbulence length scale. Based upon the freestream turbulence intensity, momentum thickness, and turbulence length scale, a first momentum thickness Reynolds number associated with a first estimated laminar/turbulent boundary transition location along the airfoil is determined. If the estimated laminar separation location is downstream of the first estimated transition, the first estimated transition is used to determine a spatial domain for running a turbulent flow model. If the estimated laminar separation location is upstream of the first estimated transition, a second estimated transition location is used to determine a spatial domain for running the turbulent flow model.

Abstract: An airflow control device comprises a body and an active material in operative communication with the body. The active material, such as a shape memory material, is operative to change at least one attribute in response to an activation signal. The active material can change its shape, dimensions and/or stiffness producing a change in at least one feature of the airflow control device such as shape, dimension, location, orientation, and/or stiffness to control vehicle airflow to better suit changes in driving conditions such as the need for increased airflow through the radiator due to increases in engine coolant temperature. As such, the device improves vehicle fuel economy while maintaining proper engine cooling. An activation device, controller and sensors may be employed to further control the change in at least one feature of the airflow control device such as shape, dimension, location, orientation, and/or stiffness of the device.

Abstract: An airflow control device comprises a body and an active material in operative communication with the body. The active material, such as a shape memory material, is operative to change at least one attribute in response to an activation signal. The active material can change its shape, dimensions and/or stiffness producing a change in at least one feature of the airflow control device such as shape, dimension, location, orientation, and/or stiffness to control vehicle airflow to better suit changes in driving conditions such as the need for increased airflow through the radiator due to increases in engine coolant temperature. As such, the device improves vehicle fuel economy while maintaining proper engine cooling. An activation device, controller and sensors may be employed to further control the change in at least one feature of the airflow control device such as shape, dimension, location, orientation, and/or stiffness of the device.

Abstract: A wing for an aircraft has a passive jet spoiler for providing yaw control by increasing drag on the wing. The spoiler comprises an inlet located near the leading edge of a lower surface of the wing and at least one outlet formed on the lower surface or on an upper surface of the wing. An internal passage connects the inlet and each outlet for allowing air to pass from the inlet to the outlet. The air exits the outlets generally normal to the respective surface of the wing, causing a laminar flow to separate from the surfaces downstream of each outlet. The separated flow increases the drag on the wing, producing a yawing moment on the aircraft. Selective placement of the outlets on the upper and lower surfaces limits undesirable roll and pitch moments. Valves are provided for selectively controlling the amount of air passing through the spoiler.

Abstract: Methods and systems for controlling shocks on airfoil lower surfaces are disclosed. An airfoil in accordance with one embodiment of the invention includes an upper surface portion having an upper surface positioned to face generally upwardly during the level flight, and a lower surface portion having a leading edge region, a trailing edge region and a lower surface positioned to face generally downwardly during level flight. A shock control protrusion extends away from the lower surface and is positioned to generate a shock extending away from the lower surface at a least one flight condition.

Abstract: A swept aircraft wing includes a leading airfoil element and a trailing airfoil element. At least one full-span slot is defined by the wing during at least one transonic condition of the wing. The full-span slot allows a portion of the air flowing along the lower surface of the leading airfoil element to split and flow over the upper surface of the trailing airfoil element so as to achieve a performance improvement in the transonic condition.

Abstract: Micro-electro-mechanical (MEM) translational tabs are introduced for enhancing and controlling aerodynamic loading of lifting surfaces. These microtabs are mounted at or near the trailing edge of lifting surfaces, deploy approximately normal to the surface, and have a maximum deployment height on the order of the boundary layer thickness. Deployment of this type of device effectively changes the camber, thereby affecting the lift generated by the surface. The effect of these microtabs on lift is as powerful as conventional control surfaces such as ailerons. Application of this simple yet innovative lift enhancement and control device will permit the elimination of some of the bulky conventional high-lift and control systems and result in an overall reduction in system weight, complexity and cost.

Abstract: In combination, an aircraft wing and fuselage, comprising the wing having camber at or near the wing leading edge which has blunted sharpness and low sweep angle, and the fuselage having indentation along the wing side thereof, and lengthwise of the fuselage.

Abstract: A method of controlling movement of a vehicle including generating a fluid jet adjacent an aerodynamic surface of the vehicle, and changing at least one of a strength and a position of a shock wave traveling over the aerodynamic surface of the vehicle by directing the jet into a boundary layer flow of air attached to the aerodynamic surface.

Abstract: This invention solves the problem of reducing the fluid friction resistance accompanying relative movement of surfaces of a solid and a liquid. A superhydrophobic coating acting as a substrate for a gaseous lubricant of very low viscosity, reducing the fluid skin friction, has a hierarchic fracal structural of the surface wherein the forms of the first hierarchic level (2, 3, 9) are located at the coating's substrate, and the forms of each successive hierarchic level (22, 33, 99) are located on the surface of the previous hierarchic level and the forms of individual higher hierarchic levels reiterate the forms of the lower hierarchic levels. Forms of at least two hierarchic levels of rows (2, 22) and ridges (3, 33, 99) occur in the coating and, also, the surface has anisotropic geometry, maximally developed fractally in the direction transverse to the direction of flow and maximally smooth in the direction of flow and, also, has channels located in the coating's substrate to ensure gas flow.

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: Active flow control devices and methods are disclosed for improving the aerodynamic efficiency of airfoils. The devices and methods pertain to applying intermittent suction or intake of low-energy boundary layer fluid into airfoils in a manner delaying or eliminating boundary layer separation.

Abstract: The present invention relates to a reconfigurable porous technology for fluid flow control system and more particularly to reconfigurable porosity fluid flow control system for vehicles such as aircraft, missiles, ground and water vehicles to improve the performance of such vehicles. The present invention further relates to a method of operating the reconfigurable fluid flow control system. In one embodiment, the present invention includes a reconfigurable porosity system for fluid flow control on the surface of an aircraft, missile, water-craft or ground vehicle comprising a porous outer skin comprising individual pores; individually addressable valves corresponding and connected to the individual pores for opening and closing the pores; and a pneumatic system for connecting the pores wherein fluid from a high pressure area of the porous outer skin can be directed to a low pressure area of the porous outer skin by opening and closing the individually addressable valves.

Abstract: The present invention relates to a flow control device and more particularly to reactive modular flow control device with deployable flow effectors. The present invention further relates to a method of operating the flow control device. One embodiment of the present invention includes a method of controlling air flow across a surface of an aircraft under certain flight conditions comprising the steps of sensing fluid separation from the surface by measuring the pressure on the surface; determining a standard deviation of the pressure measurements over a period of time; and deploying a flow of effector in response to the standard deviation of the pressure measurements exceeding a predetermined threshold number.

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 be ultrasonic and provide acoustic energy at a transition region between turbulent and laminar flows or at the leading edge of a laminar flow in order to facilitate the respective increase or decrease in drag. The ultrasonic beams may be placed at various locations of an aircraft in order to provide some flight control. The ultrasonic beams may be placed on an automobile to facilitate desired operating modes of the vehicle. The ultrasonic beams may be a further component of a parametric array for communicating audio signals ahead and behind the vehicle in addition to drag modulation.

Abstract: An active control device is disclosed comprising an array of actively controlled oscillating air jets disposed on an aircraft structure. In a preferred embodiment, the device senses parameters associated with incipient unsteady aerodynamic excitation, such as free stream gusts, shed wakes in rotor and turbomachinery flows, or oscillatory motion of trailing edge control surfaces such as ailerons. These parameters are provided as input signals to a processor. Based on the input signals, the processor generates output signals that are used to operate the air jet array in a manner counteractive to the unsteady forcing. The air jet array can be used on numerous aircraft structures, including rotor blades, wings, engine inlets, engine exhausts, blunt surfaces and nozzles.

Abstract: The present invention provides a system and method for rapidly and precisely controlling vortex symmetry or asymmetry on aircraft forebodies to avoid yaw departure or provide supplemental lateral control beyond that available from the vertical tail surfaces with much less power, obtrusion, weight and mechanical complexity than current techniques. This is accomplished with a plasma discharge to manipulate the boundary layer and the angular locations of its separation points in cross flow planes to control the symmetry or asymmetry of the vortex pattern. Pressure data is fed to a PID controller to calculate and drive voltage inputs to the plasma discharge elements, which provide the volumetric heating of the boundary layer on a time scale necessary to adapt to changing flight conditions and control the symmetry or asymmetry of the pressures and vortices.

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: The present invention relates to a reconfigurable porous technology for fluid flow control system and more particularly to reconfigurable porosity fluid flow control system for vehicles such as aircraft, missiles, ground and water vehicles to improve the performance of such vehicles. The present invention further relates to a method of operating the reconfigurable fluid flow control system.

Abstract: A vehicle capable of flight including at least one wing including at least one oscillatory momentum generator mounted therein. A thrust force from the oscillatory momentum generator is directed outwards over the wing causing a lift-generating air flow over a wing surface. A method of flying a vehicle including providing at least one wing having at least one oscillatory momentum generator mounted therein and applying a thrust force from the generator which is directed outwards over the wing and directed to the trailing edge so that a lift generating air flow is created.

Abstract: The present invention features a fluid flow regulator that functions to significantly influence fluid flow across the surface of an object, as well as to significantly effect the performance of the object subjected to the fluid. The fluid flow regulator comprises a pressure recovery drop that induces a sudden drop in pressure at an optimal pressure recovery point on said surface, such that a sub-atmospheric barrier is created that serves as a cushion between the molecules in the fluid and the molecules at the object's surface. More specifically, the present invention fluid flow regulator functions to significantly regulate the pressure gradients that exist along the surface of an object subject to fluid flow. Regulation of pressure gradients is accomplished by selectively reducing the pressure drag at various locations along the surface, as well as the pressure drag induced forward and aft of the object, via the pressure recovery drop.

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: 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 be ultrasonic and provide acoustic energy at a transition region between turbulent and laminar flows or at the leading edge of a laminar flow in order to facilitate the respective increase or decrease in drag. The ultrasonic beams may be placed at various locations of an aircraft in order to provide some flight control. The ultrasonic beams may be placed on an automobile to facilitate desired operating modes of the vehicle. The ultrasonic beams may be a further component of a parametric array for communicating audio signals ahead and behind the vehicle in addition to drag modulation.

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 are actively manipulated to control the flow behavior of the ducted fluid flow and prevent flow separation within the primary fluid flow.

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: Apparatus for controlling shock/boundary-layer interactions created by a supersonic shock on a surface of a structure, includes a cavity formed in the structure and having an opening on the surface. A plate is attached to the surface and covers the opening. A plurality of flaps are formed on the plate and is operable to cooperatively close the opening in response to subsonic airflow condition over the flaps, and open the opening to permit airflow through the cavity in response to supersonic airflow conditions over the flaps.

Abstract: An auxiliary flap is movably arranged on a planar trailing edge of an aerodynamic element such as a wing, rudder, stabilizer, or flap. The auxiliary flap is rotatable and/or slidable relative to the aerodynamic element, to move selectively into three positions. In a first position, a free edge of the auxiliary flap protrudes into an airflow boundary layer on one side of the aerodynamic element, to decrease lift. In a second position, a free edge of the aerodynamic element protrudes into an airflow boundary layer on the other side of the aerodynamic element, to increase lift. In a third neutral position, the auxiliary element does not protrude into either boundary layer, so as not to influence lift. The auxiliary flap is simple and rapidly acting. The flap protrudes substantially perpendicularly into the boundary layer flow. The auxiliary flap has a planar plate shape.

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: 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: An apparatus for controlling fluid pressure recovery includes an elongated housing having an opening at a first end thereof, an opening at a second end thereof, an inner peripheral surface, and a fluid flow passageway therethrough. The apparatus further includes a plurality of choke members fixed to the inner peripheral surface of the housing, each of the plurality of choke members being spaced from an adjacent choke member and projecting a predetermined distance into the fluid flow passageway of the longitudinal housing. The plurality of choke members sequentially produce a reduced turbulent free shear fluid layer from the first end to the second end of the elongated housing.

Abstract: Boundary layer control of a structural element in fluid stream is achieved by the following operations:

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 method for calculating parameters about an axisymmetric body in a cavity is provided. The user provides data describing the body, a cavity estimate, and convergence tolerances. Boundary element panels are distributed along the body and the estimated cavity. Matrices are initialized for each panel using disturbance potentials and boundary values. Disturbance potential matrices are formulated for each panel using disturbance potential equations and boundary conditions. The initialized matrices and the formulated matrices are solved for each boundary panel to obtain panel sources, dipoles and cavitation numbers. Forces and velocities are computed giving velocity and drag components. The cavity shape is updated by moving each panel in accordance with the calculated values. The method then tests for convergence against a tolerance, and iterates until convergence is achieved. Upon completion, parameters of interest and the cavity shape are provided.

Abstract: Apparatus for controlling shock/boundary-layer interactions created by a supersonic shock on a surface of a structure, includes a cavity formed in the structure and having an opening on the surface. A plate is attached to the surface and covers the opening. A plurality of flaps are formed on the plate and is operable to cooperatively close the opening in response to subsonic airflow condition over the flaps, and open the opening to permit airflow through the cavity in response to supersonic airflow conditions over the flaps.

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: Method and apparatus for suppressing fluid flow separation from a surface of a body during flow of a fluid along the surface of the body. At least one barrier member (for example, at least one tab) is provided extending away from the surface of the body and into a separated flow region adjacent the body surface, but not into a smooth flow region beyond the separated flow region. Where a plurality of barrier members are used, the barrier members are located spaced from each other along the direction of flow of the fluid. The barrier member suppresses upstream movement of the separation point between smooth flow along the body surface and separated flow. A chamber extending from the body surface and into the body can be positioned at the barrier member, to provide a place for vortices in the fluid flow to settle down. The barrier member can be moved from a position where it is co-planar with the body surface to a position where it extends away from the surface into the separated flow region.