Patents by Inventor Dhanvada M. Rao

Dhanvada M. Rao has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5255881
    Abstract: A pair of spaced slots, disposed on each side of an aircraft centerline and spaced well inboard of the wing leading edges, are provided in the wing upper surfaces and directed tangentially spanwise toward thin sharp leading wing edges of a highly swept, delta wing aircraft. The slots are individually connected through separate plenum chambers to separate compressed air tanks and serve, collectively, as a system for providing aircraft lift augmentation. A compressed air supply is tapped from the aircraft turbojet power plant. Suitable valves, under the control of the aircraft pilot, serve to selective provide jet blowing from the individual slots to provide spanwise sheets of jet air closely adjacent to the upper surfaces and across the aircraft wing span to thereby create artificial vortices whose suction generate additional lift on the aircraft. When desired, or found necessary, unequal or one-side wing blowing is employed to generate rolling moments for augmented lateral control.
    Type: Grant
    Filed: March 25, 1992
    Date of Patent: October 26, 1993
    Assignee: Vigyan, Inc.
    Inventor: Dhanvada M. Rao
  • Patent number: 5094411
    Abstract: Individually deflectable, segmented, vortex flaps are provided on the leading edges of a delta wing supersonic aircraft to permit selective lateral and directional control moments to be created on the aircraft at high angles of attack, where conventional elevons and rudders have become ineffective. By selectively deflecting the segmented vortex flaps simultaneously in the same direction or differentially, the lateral and directional control of high-swept, thin wing, supersonic speed aircraft, at high angles of attack, is improved.
    Type: Grant
    Filed: October 19, 1990
    Date of Patent: March 10, 1992
    Assignee: Vigyan, Inc.
    Inventor: Dhanvada M. Rao
  • Patent number: 4786009
    Abstract: Method and apparatus for controlling the yaw and pitch of air vehicles at high angles of attack by controlling the vortex pattern around the forebodies of the air vehicles by means of deflecting strakes 11 and 16.
    Type: Grant
    Filed: January 5, 1987
    Date of Patent: November 22, 1988
    Assignee: Vigyan Research Associates, Inc.
    Inventors: Dhanvada M. Rao, Daniel G. Murri
  • Patent number: 4485992
    Abstract: Traditional roll control systems such as ailerons, elevons or spoilers are least effective at high angles of attack due to boundary layer separation over the wing. This invention uses independently deployed leading edge flaps 16 and 18 on the upper surfaces of vortex stabilized wings 12 and 14, respectively, to shift the center of lift outboard. A rolling moment is created that is used to control roll in flight at high angles of attack. The effectiveness of the rolling moment increases linearly with angle of attack. No adverse yaw effects are induced. In an alternate mode of operation, both leading edge flaps 16 and 18 are deployed together at cruise speeds to create a very effective airbrake without appreciable modification in pitching moment. Little trim change is required.
    Type: Grant
    Filed: August 12, 1983
    Date of Patent: December 4, 1984
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Dhanvada M. Rao
  • Patent number: 4225102
    Abstract: Apparatus for alleviating high angle-of-attack side force on slender pointed cylindrical forebodies such as fighter aircraft, missiles and the like and employing a symmetrical pair of helical separation trips to disrupt the leeside vortices normally attained. The symmetrical pair of trips start at either a common point or at spaced points on the upper surface of the forebody and extend along separate helical paths along the circumference of the forebody.
    Type: Grant
    Filed: March 12, 1979
    Date of Patent: September 30, 1980
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Robert A. Administrator of the National Aeronautics and Space Administration, with respect to an invention of Frosch, Dhanvada M. Rao