Abstract: Apparatus and methods for alleviating rotary aircraft downloads are disclosed. In one embodiment, a rotary aircraft includes an airframe assembly having a fuselage, at least one rotor assembly operatively coupled to the airframe assembly and configured to provide a downwash over at least a portion of the airframe assembly during operation of the at least one rotor assembly, and at least one download alleviation strake operatively coupled to the fuselage, each download alleviation strake extending at least partially along a length of the fuselage and being configured to reduce a downwash download during operation of the at least one rotor assembly. In some embodiments, the airframe assembly includes at least one fuel tank, and the at least one download alleviation strake is coupled to the at least one fuel tank. The download alleviation strake may be pivotably coupled to the at least one fuel tank.

Abstract: An aircraft structure comprising: a spar; a primary cover attached to the spar and extending on a first side of the spar; and a secondary cover positioned on a second side of the spar and partially overlapping an internal surface of the primary cover. A bracket is attached to the spar, and a spacer is provided between the secondary cover and the bracket. The spacer is sized so that the primary and secondary covers together form a substantially continuous external aerodynamic surface. The structure provides an alternative to conventional butt-strap arrangements.

Abstract: Reinforced cover for gaps in an aerodynamic contour of a vehicle, with a first attachment section 1a attachable to a structural element 2, 5 of the vehicle 11, on a first axial plane I; a second elastic section 1c which covers a gap 3 which is located between a fixed part 5 and a moving part 6, 12 of the vehicle 11, and provided with a low-friction coating 8 on its inner surface 1e, an outer surface 1k with a fiberglass layer 7a; a main internal body 9 of an elastic material, a flexible transition section 1g between the first and the second section, 1a, 1c; the outer surface 1k of the second section 1c flushing with the outer surface 5a and extending towards the free end 1d as a continuation of the outer surface 5a of the fixed part 5.

Abstract: A fairing suitable for enclosing a component mounted on an exterior surface of a mobile platform, and more particularly on an outer surface of a high speed mobile platform such as a jet aircraft or an aerospace vehicle. The fairing provides aggressive closure angles for optimum RF performance when used to house an antenna that is scanned to varying azimuth and elevation angles. The fairing further provides low aerodynamic drag, is scalable to enclose components having wide ranging dimensions, and provides attached flow with minimum separation of airflow thereover for airflows experienced by high speed jet aircraft, and reduces or eliminates RF reflections within the fairing from the RF beam of the antenna.

Abstract: An aerodynamic airflow deflecting device for a landing gear retracting into a housing of an aircraft, comprising at least one element for closing the housing that is, through the action of a control device, able to occupy a position for shielding at least a part of the landing gear against the aerodynamic airflow, thus constituting a noise reducing aerodynamic device. The closing element can in particular include at least one trap door element that is, through the action of the control device, movable between a first position for closing the housing, a second position allowing the landing gear to exit and a third position constituting said shielding position.

Abstract: A capped winglet comprising a helical portion having a smooth vertical curvature of 180°±approximately 20° from the plane of the unbounded end of a wing, and a generally planar cap contiguous with the helical portion of the winglet at the end of its curvature away from the wing, the cap having a free inboard end and a chord tapered toward the free end.

Abstract: An airfoil for use on a high speed, jet powered airborne mobile platform and secured to an exterior surface of said mobile platform at a location so as to be disposed within a boundary layer during flight of the mobile platform. The airfoil produces a peak Mach number for airflow over a longitudinal centerline of said airfoil that is no greater than about Mach 1.2 when said mobile platform is moving at a speed of about Mach 0.85 with a relative constant Mach number flow over a region defined as at least an approximate 20% length of maximum thickness of said airfoil. The airfoil also has a pressure distribution (Cp) that is positive at a trailing edge thereof.

Abstract: A hub fairing system (12) for a stopped-rotor aircraft (10) having a fuselage (14) including a hub (16). The hub (16) is mechanically coupled to the fuselage (14) and to multiple blades (40) and is rotated by an engine (22). A retractable fairing (60, 64) covers a portion of the hub (16). An actuator (26) is coupled to the fairing (60, 64). A controller (28) is coupled to the actuator (26) and retracts the fairing (60, 64). A method of reducing drag on the aircraft includes transitioning between a rotary-wing mode and a fixed-wing mode. The fairing (60, 64) is deployed over a portion of the hub (16) upon the completion of the transition between flight modes.

Abstract: A rotor hub fairing system includes an upper hub fairing, a lower hub fairing and a shaft fairing therebetween. The rotor hub fairing system is attached to the counter-rotating, coaxial rotor system through a bearing arrangement such that the shaft fairing may be positioned at an azimuthal position about the main rotor axis of rotation relative the airframe by a de-rotation system. The de-rotation system controls the position of the shaft fairing about the axis of rotation such that the shaft fairing is prevented from rotating freely in unison with either shaft as may otherwise result during some flight regimes.

Abstract: A de-rotation system includes a first ring gear defined about an axis of rotation, a second ring gear defined about the axis of rotation and a gear set in meshing engagement with the first ring gear and the second ring gear to control a position of a housing about the axis of rotation.

Abstract: The present invention relates to a method for manufacturing a solid body having a superhydrophobic surface structure formed by using a surface treatment of a metal body, a replication process, and a polymer sticking phenomenon to increase efficiency of fluid transfer and prevent foreign materials from being accumulated in the tube, and a superhydrophobic fluid transfer tube using the method. The superhydrophobic fluid transfer tube includes a fluid guider and a solid body provided on a fluid contact surface of the fluid guider and has micrometer-scaled unevenness and nanometer-scaled protrusions.

Abstract: The nacelle drag reduction device comprises a substantially circular and axis symmetrical external airfoil concentric with a aft section of the nacelle and located outside a propulsive jet zone defined behind the engine when operating, the airfoil being positioned at a location providing a maximum streamline angle with reference to the main axis of the engine and a highest streamline curvature.

Abstract: An aircraft turret and fairing assembly for facilitating transmission of a directed energy beam from a directed energy device includes a turret section for directing an energy beam. The assembly also includes a fairing section aft of and adjacent to the turret section. Each of the turret section and the aft fairing section are coupled to an aircraft. The assembly also includes at least one sensor for detecting air speed of the aircraft and air pressure. The turret section and the aft fairing section are configured and positioned relative to one another to direct airflow for generating an aeroacoustic resonance within a desired frequency range in an area aft of the turret section.

Abstract: An embodiment of an aircraft wing includes a main wing section and a variable incidence wing tip. The main wing section is adapted to connect to an aircraft fuselage at a first angle of incidence. The variable incidence wing tip is connected to the main wing section so that the variable incidence wing tip is rotatable to angles of incidence that are different from the first angle of incidence. An embodiment of a method for operating an aircraft includes generating a control signal based on an indication of a desired angle of incidence of a variable incidence wing tip, conveying the control signal to a wing tip rotation mechanism, and rotating the variable incidence wing tip in accordance with the control signal, so that the angle of incidence of the variable incidence wing tip is different from an angle of incidence of the main wing section.

Abstract: The connection of a rudder unit on the fuselage of an aircraft frequently leads to an inhomogeneous flow of forces in the connecting region between the rudder unit and the fuselage or even to an offset of the flow of forces relative to the centroidal axis, e.g., due to multiple-bolt connections. This is extremely disadvantageous with respect to static considerations. One embodiment of the present invention proposes a connection for a rudder unit on an aircraft fuselage, in which the flow of forces resulting from the connection between the rudder unit spars and the fuselage frames extends in a largely homogenous fashion from the rudder unit spars to the fuselage frames and into the fuselage. The connecting elements are advantageously arranged within the rudder unit and the fuselage in such a way that no additional enveloping aerodynamic fairings are required that would result in an additional increase in the aerodynamic drag.

Abstract: An extra narrow wing system for airplanes combining the advantages of sufficient lift like a conventional airplane wing with reduced space requirements. A V-shaped nudge at the back side of the main wing helps to overcome the limitations of extreme delta-wings and allows very narrow wings with angles of as low as 0 degrees but sufficient lift for a propeller or jet operated plane. Front and tail wings are one aerodynamic system. The system results in very narrow airplane designs useful when operating under space constraints.

Abstract: A nacelle assembly for a turbine engine has a cowl for a turbine engine. The cowl has a first surface spaced from a second surface. The second surface defines defining a bypass flow passage. A flow volume is spaced between the first surface and the second surface. A plurality of holes are disposed on the cowl. Each of the plurality of holes are configured to alter local air pressure about one of the first surface and the second surface of the cowl. The plurality of holes are in communication with the flow volume.

Abstract: A fairing for streamlining the junction between the horizontal stabilizer and the fuselage or the fin of an aircraft, comprising an upper fairing shell, a lower fairing shell, a leading edge extension, and several fittings to join the upper and lower fairing shells to the horizontal stabilizer. The upper and lower fairing shells are solid laminates of composite material that are designed with a shape, composition, and thickness such that they can be elastically deformed when they are fitted to the horizontal stabilizer, providing a contact force permitting them to lay permanently in contact with the fuselage or fin. A process for manufacturing the fairing shells.

Abstract: A fluid dynamic article includes a treated surface 32 and a transversely opposite surface 34. The treated surface 32 is substantially completely populated by a series of boundary layer flow guides 36 comprising longitudinally extending, laterally distributed, alternating troughs 40 and ridges 42. The depth d and height h of the troughs and ridges are substantially constant in a longitudinal direction. The opposite surface 34 has a configuration independent of the treated surface 32. The article may take the form of a nacelle 16 or 20 for an aircraft turbine engine.

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 apparatus for attenuating acoustic resonance generated by flow over a cavity in a surface comprises a plurality of flat flaps proximate to an upstream edge of the cavity. The flaps are disposed in an array spaced in a width direction of the cavity edge, and are oscillated by the flow in two degrees of freedom solely by the flow, independent of an actuation mechanism. Each flap includes a first hinge generally coextensive with the surface for enabling oscillation in a first degree of freedom and a second hinge orthogonal to the first hinge and forming a tab for enabling oscillation in a second degree of freedom. The hinges are constructed with torsional spring constants that provide predetermined oscillation frequencies and magnitudes. The apparatus can include a deployment mechanism for moving each flap between a stowed position wherein it is generally flush with the surface and a deployed position wherein the flap can be oscillated by the flow.

Abstract: A joint cover in an aircraft has a clamp section and a cover section for covering a joint. The clamp section is used to mount the cover section over the joint. The joint cover conceals the joint and secures the joint from intrusion of foreign objects. One example presents information to passengers, incorporating visual displays or other devices within the cover section. For example, the joint cover may include a cover section and a clamp section of an elastic material that deforms under pressure, concealing the joint even during compression and decompression of the aircraft, which causes movement of the panels defining the joint.

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 system and method for controlling a freestream air flow over a surface of an airborne mobile platform, for example an aircraft. In one implementation the system includes a plurality of plasma actuators used on an undersurface of a fuselage of an aircraft upstream of a weapons bay of the aircraft. When the plasma actuators are energized an induced flow is created adjacent the actuators. The induced flow operates to deflect the shear layer created when the freestream air flow moves over the weapons bay (while the bay doors are open), away from the weapons bay. This significantly reduces the oscillating acoustic pressure waves that would normally be produced if the shear layer turns into the weapons bay. The system and method significantly reduces acoustic noise inside the weapons bay and improves separation of ordnance from the weapons bay.

Abstract: A hub for a human powered vehicle includes a rotation axis, a hub body formed generally symmetrically about the rotation axis, the hub body having a radially-outward-facing surface that includes a plurality of surface features for improving the aerodynamic efficiency of the hub as it passes through a fluid, and a wheel assembly attachment member formed along a circumference of the hub body, the wheel assembly attachment member being structured for attachment to one of a plurality of spokes and the center of a disc wheel. The surface features may include a series of depressions or a series of projections, and such features may have a dimple shape that can be formed in a variety of shapes including those with a cylindrical wall and a planar bottom or a hemispherical bottom. Alternately, such surface features may have a hemispherical shape.

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: In an aircraft comprising a fuselage and a belly fairing, the fairing is made of two independent parts. For example, a first part of the fairing comprises a front section, a central section and a first portion of a rear section. A second part of the fairing comprises a second portion of the rear section. The second part can shift relative to the first part of the fairing. Also disclosed is a belly fairing for aircraft comprising two independent parts.

Abstract: An air discharge device in the form of a grid that is connected to an aerodynamic surface of an aircraft, whereby includes a number of openings delimited by intermediate zones that are arranged in the extension of the aerodynamic surface of the aircraft and at least one longitudinal reinforcement or passage separating the openings into at least two stages, where the arrangement, the dimensions and/or the surface ratio of the perforated zones that correspond to openings and non-perforated zones that correspond to intermediate zones or to the passage(s) are such that they make possible creating a depression close to the air discharge.

Abstract: A supersonic guided weapon has radiation sensitive apparatus carried behind a radiation transparent window the window being formed within an open recess in the weapon nose, the recess being such that at supersonic speeds it forms shock waves which trap air within the recess to provide a measure of kinetic heat insulation for the window and also a minimum of supersonic drag. An elongate nose region can be provided ahead of the recess to house further radiation sensitive or radiation emitting apparatus.

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

Abstract: Reinforced cover for gaps in an aerodynamic contour of a vehicle, with a first attachment section 1a attachable to a structural element 2, 5 of the vehicle 11, on a first axial plane I; a second elastic section 1c which covers a gap 3 which is located between a fixed part 5 and a moving part 6, 12 of the vehicle 11, and provided with a low-friction coating 8 on its inner surface 1e, an outer surface 1k with a fiberglass layer 7a; a main internal body 9 of an elastic material, a flexible transition section 1g between the first and the second section, 1a, 1c; the outer surface 1k of the second section 1c flushing with the outer surface 5a and extending towards the free end 1d as a continuation of the outer surface 5a of the fixed part 5.

Abstract: A linear cavity is provided on the leading edge of an object that is subject to the flow of liquids or gasses, where said cavity preferably has a wall that follows the curvature of a diminishing sine wave, although other configurations are possible that do not follow a specific sine wave. The cavity accepts the flow of liquids or gasses that enter into the cavity, and where the dimensions of the cavity cause the flow of liquids or gases within it to form a pressure node that extends forward of the cavity. The pressure node provides a wedge means to cause oncoming gasses or liquids to divert around the object body ahead of the object body itself, decreasing turbulence around the periphery of the object. The cavity may be spherical, in the instance of a missile, plane, or underwater transportation means, or may be linear, in the instance of an automobile grill that is subject to wind, or a bridge support, where the bridge support has to maintain position against the flow of current.

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 vertical stabilizer is configured to minimize the rate of change of cross-sectional area distribution of the vehicle or device to which the vertical stabilizer is mounted. One or more “waisted” areas can be included at the tip and/or the root of the vertical stabilizers, as well as over the distance from tip to root of the vertical stabilizer. In some situations, a strake is mounted on the vehicle or device, such as an aircraft, and the vertical stabilizer is mounted to the tip of the strake. The strake can also be area ruled with one or more “waisted” sections at the juncture of the vertical stabilizer. Applying area ruling to the vertical stabilizer helps to further reduce the drag of the vehicle or device.

Abstract: Objectives to be achieved by this invention are the provision of a method for determining the ultimate fuselage shape of supersonic aircraft by integral modification of the upper and lower surface shapes of the fuselage, to reduce sonic boom without increasing wave drag, as well as the provision of such a fuselage front section shape. A method for determining the fuselage shape of an aircraft for supersonic flight of this invention employs different methods of determining the fuselage lower-surface shape and the fuselage upper-surface shape, whose upper and lower boundary is defined for each fuselage cross-section by the horizontal line including two points at which the fuselage width from the bilateral symmetry plane is maximum.

Abstract: The present invention features a fluid flow regulator that functions to influence fluid flow across an airfoil or hydrofoil, as well as various rotating or rotary devices, including propellers, impellers, turbines, rotors, fans, and other similar devices, as well as to affect the performance of airfoils and hydrofoils and these rotary devices subjected to a fluid. The fluid flow regulator comprises a pressure recovery drop that induces a sudden drop in pressure at an optimal pressure recovery point on the 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 airfoil's or hydrofoil's surface. More specifically, the fluid flow regulator functions to regulate the pressure gradients that exist along the surface of an airfoil or hydrofoil.

Abstract: A nose cap and control strut assembly for supersonic aircraft is disclosed. In one embodiment, the nose cap extends forward from the nose of the aircraft to deflect shock waves and decrease draft during supersonic flight. In another embodiment, control struts extending from the nose of the aircraft have control surfaces which provide yaw and pitch control for the aircraft. The control struts may be rotatable around axes substantially parallel with the longitudinal axis of the aircraft. The control struts may also be retractable into the aircraft. The nose cap may be mounted at the forward ends of the control struts in such a manner that the nose cap remains in a stationary position with respect to the aircraft when the control struts are rotated.

Abstract: A fairing C is arranged on a rotor 9 of a rotorcraft having a cap 5 secured to the end 10 of the head of the rotor 9. The fairing C further comprises at least one air deflector member D provided with a ring 6 and spacers 4, the spacers 4 enabling the ring 6 to be secured to the cap 5.

Abstract: The present invention is directed to a micro-array surface that provides for either drag reduction or enhancement. In one aspect, an aerodynamic or hydrodynamic wall surface that is configured to modify a fluid boundary layer on the surface comprises at least one array of roughness elements disposed on and extending therefrom the surface. In one example, the interaction of the roughness elements with a turbulent boundary layer of the fluid reduces the skin friction drag coefficient of the surface over an identical smooth surface without the roughness elements.

Abstract: Methods for configuring aircraft that may be implemented to integrate aircraft sonic boom constraint requirements with the design process for a supersonic aircraft, for example, to reconcile a target sonic boom constraint with the internal layout and balance of the aircraft during the design phase. The disclosed methods may advantageously be employed in one embodiment to allow a sonic boom-constrained aircraft design configuration solution to be reached that incorporates a desired sonic boom signature with the requirements of an internal configuration layout. Resulting aircraft configurations may be usefully employed for achieving sonic boom suppression on any type of supersonic-capable aircraft, for example, a civil supersonic business aircraft.

Abstract: A fairing panel retainer can include a retainer strip that is configured to conform to the contour of a vehicle body. The retainer strip includes alternating body attachment segments and raised panel attachment segments in a generally corrugated configuration. In addition, each of the body attachment segments includes a body fastener interface configured to accept a permanent fixed fastener to attach the fairing panel retainer to the vehicle body. Each of the panel attachment segments can include a panel fastener interface, for example, a bore through the panel attachment segment and a fastener plate slidably attached to a lower surface of the panel attachment segment. The body fastener interfaces and the panel fastener interfaces can be closely aligned along a longitudinal line or arc of the retainer strip. The fairing panel retainer can also include a transition surface to provide a smooth transition from the vehicle body surface to a fairing panel.

Abstract: Wake vortices are made less detectable or reduced in their effect on nearby vehicles by re-orientation of vorticity about an axis in the direction of vehicle motion to transverse vorticity interacting with the longitudinal vorticity. The re-orientation may be by a flapping foil, and arrangements of a plurality of foils moving toward or from each other may be used. Alternatively, fluid may be injected longitudinally between opposite surfaces each having a port so that selective suction through the ports alternately attaches the fluid to the surfaces to deflect the fluid from the longitudinal direction and generate transverse vortices. Oppositely rotating vortices may be formed by separators extendable from each surface to engage the deflected fluid, and extension of the separators may be varied to control vortex trajectory. The transverse vortices may be intermittent, selected for speed, or made asymmetric for maneuvering.

Abstract: The present invention relates to a new type aircraft. The aircraft includes the airframe and wing, characterized in that the transverse section of airframe has an oblate (oval) profile with corrugated area on the ventral of airframe; the aircraft has uneven friction areas on the underside surface of wing; there are fireproof & anti-wear layers on the envelopes of airframe ventral and friction areas; the said fireproof & anti-wear layers have tire rubber material. When the aircraft is in motion with high velocity, the friction with air is increased, which produces bigger lift with more aircraft load and shortened takeoff & landing distance of aircraft, meanwhile the safe peril to aircraft caused by the shear transformation of wind in flight is prevented effectively; the fireproof & anti-wear layers on the envelopes of airframe ventral and friction areas have an effect on higher anti-wear proof and longer aircraft life.

Abstract: A shock wave in a gas is modified by emitting energy to form an extended path in the gas; heating gas along the path to form a volume of heated gas expanding outwardly from the path; and directing a path. The volume of heated gas passes through the shock wave and modifies the shock wave. This eliminates or reduces a pressure difference between gas on opposite sides of the shock wave. Electromagnetic, microwaves and/or electric discharge can be used to heat the gas along the path. This application has uses in reducing the drag on a body passing through the gas, noise reduction, controlling amount of gas into a propulsion system, and steering a body through the gas. An apparatus is also disclosed.

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: It is an object of the present invention to provide a flying object using a thin elongated nose cone with a small tip angle for reducing the air resistance during flying, wherein the maximum loading capacity can be increased without decreasing the volume efficiency of the flying object by limitations placed on the accommodation space, regardless of the structure thereof. In the flying object in accordance with the present invention, which comprises a nose cone in the tip portion, the nose cone portion has a compressed structure in the axial direction during accommodation and expands on the tip side in the axial direction during flying, due to an expandable nose cone structure such that a disk with a small diameter is disposed in the forward position and the disks with a successively increasing diameter are disposed in the axial direction.

Abstract: A bicycle wheel includes a tire engaging portion located at the outward perimeter of the wheel, an inner portion located radially inward from the tire engaging portion A pair of air engaging side surfaces extend radially between the inner portion and the tire engaging portion forming the sides of the wheel. The air engaging side surfaces contain a plurality of surface features designed to create a turbulent boundary layer when the wheel travels through air to reduce aerodynamic drag on the wheel.

Abstract: The invention described here provides better aerodynamics in airplane wheel fairings. A great improvement is achieved by putting doors on the fairing that completely enclose the wheel. This eliminates drag from the part of the tire that extends outside of a normal wheel fairing. It also eliminates drag from the turbulence associated with the gap between the wheel and the lower edge of a normal fairing. The described wheel fairing is very close to the size and shape of an ideal fairing that could totally enclose an isolated wheel assembly, but would not allow the airplane to land. In fairings where the gear leg enters the top of the fairing, drag is reduced by having a sharp ridge on the top of the fairing, rather than the rounded fairing that is presently used. A further reduction in total drag on the wheel fairing (at least in airplanes traveling around 100 m/s or more) is achieved by making the length to width ratio of the fairing in the range of 3.5.

Abstract: A lifting foil for an aircraft, a hydrofoil or the like having a pair of courses or wings. Vortex losses due to spanwise fluid flow are substantially reduced by joining the tips of the courses with flow guides configured for jointly terminating the undesired flows. Termination is effected by providing the flow guides with crossections cambered for reducing the dynamic pressure of fluid flowing in a spanwise direction across flow guide surfaces.