Compressible Flow Patents (Class 244/35A)
  • Patent number: 5897076
    Abstract: A supersonic flight aircraft having a longitudinally forwardly extending fuselage having an axis in the direction of flight, and a wing, and which comprises the wing extending generally laterally relative to the axis, and having a leading edge angled forward or rearwardly relative to a normal to the axis at an angle , and the wing having leading edge sharpness defined by upper and lower wing surfaces, which taper toward the leading edge to define an angle .delta., closely proximate the leading edge at all spanwise locations; the angle and sharpness .delta.
    Type: Grant
    Filed: May 20, 1996
    Date of Patent: April 27, 1999
    Inventor: Richard R. Tracy
  • Patent number: 5875998
    Abstract: A method and an apparatus are provided for optimizing the aerodynamic effect of the airfoil of an aircraft by defined changes in camber. The method includes the following steps:a. determining the flow for the flight condition caused by the change in camber,b. comparing the ascertained characteristic values with stored nominal reference values for an optimal flow,c. forming differential values between the characteristic values and the stored nominal reference values,d. deriving actuator signals from the differential values, ande. changing the camber by motor, based on the actuator signals, for minimizing the differential values.The optimum wing flow is thereby maintained more exactly. For transonic wings, the position and strength of compression shocks is also effectively controlled, which leads to a reduction of the direct shock induced separation.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: March 2, 1999
    Assignee: Daimler-Benz Aerospace Airbus GmbH
    Inventors: Wolfgang Gleine, Reinhard Hilbig, Hans-Joachim Wendt
  • Patent number: 5836549
    Abstract: A jet airplane capable of supersonic flight has airfoils with leading edges. Each leading edge has a cavity which extends for substantially the entire length of the airfoil. The leading edge also has a cover which is approximately the same size as the cavity. The cover has an open position and a closed position. When the cover is in the open position, the leading portion has a concave profile. When the cover is in the closed position, the leading portion has a convex profile that gives the airfoil a conventional shape. The cover is rotated to the open position when the airplane reaches supersonic speed. At supersonic speed, a shock wave forms on the leading edge of the airfoil. However, the cavity forms a compression zone between the shock wave and the leading edge, diverting the heat and pressure of the shock wave away from the airfoil. Downstream from the compressed zone, pressure wakes form along the airfoil and cool the airfoil.
    Type: Grant
    Filed: January 10, 1997
    Date of Patent: November 17, 1998
    Assignee: Lockheed Martin Corporation
    Inventor: Boyd B. Bushman
  • Patent number: 5730391
    Abstract: A body configuration for improving the fluid-dynamic performance efficiency of aircraft and watercraft comprises a generally conical upper segment (54) and a generally conical lower segment (56) that are joined at a common base plane (53), achieved by inverting the conical lower segment (56). The slopes of the conical surfaces are determined by the prescribed planform of the craft or vehicle and by the height of the conical segments wherein the height of the conical upper segment (h.sub.u) is less than and typically two-thirds that of the conical lower segment (h.sub.L). Although not limited to elliptical planforms, a generally circular planform (52) is preferred for a vertical takeoff and landing aircraft operating in the subsonic flight regime and an elliptical planform (68), with a large aspect ratio for takeoff and low-speed flight, then rotating to a low-aspect-ratio orientation for supersonic flight operation, is preferred for supersonic transport and single-stage-to-orbit type aircraft.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: March 24, 1998
    Inventors: John A. Miller, Jr., William A. Losey, deceased, by Marion E. Losey, executor
  • Patent number: 5518204
    Abstract: A supersonic flight aircraft having a longitudinally forwardly extending axis in the direction of flight, and a wing, comprising a wing extending generally laterally relative to the axis, and having a leading edge angled forward or rearwardly relative to a normal to the axis at an angle .lambda., and the wing having a maximum thickness t; the angle .lambda. and thickness t characterized that in that in supersonic flight conditions, the forwardmost shock wave produced in association with the wing extends generally along or rearwardly of the leading edge, whereby laminar airflow conditions are maintained over the leading edge and adjacent the surface of the wing.
    Type: Grant
    Filed: June 13, 1994
    Date of Patent: May 21, 1996
    Inventor: Richard R. Tracy
  • Patent number: 5358156
    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.
    Type: Grant
    Filed: June 18, 1993
    Date of Patent: October 25, 1994
    Assignee: Vehicle Research Corporation
    Inventor: Scott Rethorst
  • Patent number: 5348256
    Abstract: A supersonic aircraft having highly swept subsonic leading edge portions of the wings provided with boundary layer control suction slots. When the airplane is operating at high angles of attack under circumstances where noise is objectionable, air is drawn in through the suction strips to alleviate separated air flow and substantially eliminate (or at least alleviate) vortices that would otherwise develop over the upper wing surface. This improves the L/D ratio and permits the engines to be at a lower power setting, thus alleviating noise. There are shown a double delta planform configuration, and an arrow plan form configuration. Also, the boundary layer control suction can be used in conjunction with laminar flow control suction.
    Type: Grant
    Filed: May 13, 1992
    Date of Patent: September 20, 1994
    Assignee: The Boeing Company
    Inventor: Pradip G. Parikh
  • Patent number: 5322242
    Abstract: A supersonic flight aircraft having a longitudinally forwardly extending axis in the direction of flight, and a wing, comprising a wing extending generally laterally relative to the axis, and having a leading edge angled forward or rearwardly relative to a normal to the axis at an angle .OMEGA., and the wing having a maximum thickness t; the angle .OMEGA. and thickness t characterized that in that in supersonic flight conditions, the forwardmost shock wave produced in association with the wing extends generally along or rearwardly of the leading edge, whereby laminar airflow conditions are maintained over the leading edge and adjacent the surface of the wing.
    Type: Grant
    Filed: February 3, 1993
    Date of Patent: June 21, 1994
    Inventor: Richard R. Tracy
  • Patent number: 5314142
    Abstract: A swept forward wing for aircraft comprising an inner wing portion and an outer wing portion in which the upper surface curvature of the inner wing portion is designed to create three dimensional flow thereover to manipulate the sweep of the isobars and prevent desweeping thereof, the inner wing portion including a wing root section (4) having a far aft maximum thickness position (14) coupled with high camber in the region of said maximum thickness position, said wing root section (4) further including a negatively cambered leading edge portion (10) and a nose-down twist configured to suppress high leading edge velocities, the combination of thickness and camber forms aft of the leading edge region (10) causing the flow to accelerate until a maximum velocity is reached relatively far back on the wing.
    Type: Grant
    Filed: March 18, 1992
    Date of Patent: May 24, 1994
    Assignee: British Aerospace Public Limited Company
    Inventors: Alison J. Rao, Francis B. Ogilvie
  • Patent number: 5039032
    Abstract: A highly tapered wing tip extension added to the tip of an existing swept, trapezoidal airplane wing for reducing high speed drag significantly. A smaller, highly swept, extension does not require a leading edge device to protect against low speed stall. A larger, less swept, extension requires a tapered slat for which two mechanisms are presented. The principles of the present invention are also applicable to the design of new aircraft.
    Type: Grant
    Filed: May 19, 1989
    Date of Patent: August 13, 1991
    Assignee: The Boeing Company
    Inventor: Peter K. C. Rudolph
  • Patent number: 4718619
    Abstract: The manoeuverable supercritical wing section with a t/c ratio of 8-9%, flexible at 70%-80% chord by means of a flap to induce expansion thereover, and perhaps having a minimum curvature region on the upper surface just ahead of the flexing region.
    Type: Grant
    Filed: July 20, 1984
    Date of Patent: January 12, 1988
    Assignee: Ministry of Defence
    Inventors: Patrick R. Ashill, Donald Pierce, Desmond A. Treadgold, John L. Fulker
  • Patent number: 4598886
    Abstract: An aircraft intended to fly at supersonic Mach mnumbers is disclosed. The aircraft utilizes a double parasol wing arrangement, with a power plant nacelle located under the wing on each side of the fuselage. Each nacelle is located at the focus of a reflection parabola formed by the undersurface of each wing. In flight the shock wave pressure field created by the nacelles is reflected and redirected by the parabolic wing surface and thereby transformed into beneficial lift. The separation distance between each wing and its respective nacelle is arranged to maximize multiple reflections to thereby further enhance the lift created.
    Type: Grant
    Filed: August 13, 1979
    Date of Patent: July 8, 1986
    Assignee: The Boeing Company
    Inventors: Gottfried O. Friebel, Robert M. Kulfan
  • Patent number: 4582276
    Abstract: An aerodynamic structure which when included into the design of a supersonic aircraft provides the aircraft with a higher lift/drag ratio than has been obtainable previously in supersonic aircraft design. In a preferred embodiment, the aerodynamic structure has the general shape of a modified U-channel with each of the legs of the U-channel being configured in cross section as an isosceles triangle and extending from a cross plate. The vertical apices of each triangle face each other and are separated so that shock waves originating from the leading edges of the aerodynamic structures are cancelled by expansion waves being generated from the vertical apices. At supersonic speeds lift of the aircraft is created by a pressure field generated by a shock-expansion system acting on the cross plate of the U-channel.
    Type: Grant
    Filed: December 27, 1983
    Date of Patent: April 15, 1986
    Assignee: Northrop Corporation
    Inventor: Heinz A. A. Gerhardt
  • Patent number: 4412664
    Abstract: This invention is an airfoil which has particular application to the blade or blades of rotor aircraft such as helicopters and aircraft propellers. The airfoil thickness distribution and camber are shaped to maintain a near zero pitching moment coefficient over a wide range of lift coefficients and provide a zero pitching moment coefficient at section Mach numbers near 0.80 and to increase the drag divergence Mach number resulting in superior aircraft performance.
    Type: Grant
    Filed: June 25, 1982
    Date of Patent: November 1, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Kevin W. Noonan
  • Patent number: 4405102
    Abstract: A wing structure for an aircraft designed for both STOL and supersonic flight conditions includes a biplanar wing arrangement in which the lower wing section is staggered behind the upper wing section and the lower wing section is designed for both translational and rotational displacements relative to the upper wing section. For short takeoff and landing capabilities, the lower wing section is rotated and translated relative to the upper wing section so that the leading edge of the lower wing section is adjacent to the trailing edge of the upper wing section. For high speed supersonic flight, the lower wing section is adjacent to the trailing edge of the upper wing section. For high speed supersonic flight, the lower wing section is rotated and translated relative to the upper wing section so that the wing sections are substantially parallel.
    Type: Grant
    Filed: November 20, 1981
    Date of Patent: September 20, 1983
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Robert M. Taylor