Patents Assigned to Vigyan Research Associates, Inc.
  • Patent number: 4867397
    Abstract: An apparatus and process for reducing the aerodynamic drag on land transport vehicles are disclosed wherein a pair of vertical panels 34, 36 (FIG. 3) are disposed on the forward surface of a vehicle body 30 and facing the airstream encountered during vehicle movement. Panels 34, 36 (and similar panels as shown in FIGS. 4-6 and 9) are thin rigid flat plates and disposed in spaced relationship from each other and spaced from the vehicle sides. An additional thin panel 59 secured to and spanning the pair of vertical panels is employed in the embodiment illustrated in FIG. 5. Panel height and location, relative to the vehicle surface, influences the drag coefficient of the vehicle body. This drag reduction is accomplished due to the transition in the flow, consequent to the flow separation at the panels, leading to flow reattachment to the vehicle body surface near the front thereof, as illustrated in FIG. 8.
    Type: Grant
    Filed: November 13, 1987
    Date of Patent: September 19, 1989
    Assignee: Vigyan Research Associates, Inc.
    Inventors: Bandu N. Pamadi, Lawrence W. Taylor, Jr.
  • Patent number: 4820914
    Abstract: A technique for controlling the gain of a photomultiplier tube (PMT) 20. A voltage divider (resistors 45-49 in FIG. 1 and zener diodes 60-65 in FIG. 3) is used to control the potentials on dynodes 5, 7, and 9 of PMT 20. Transistor switches 53 and 58 provide the control of the voltage divider in FIG. 1 and photodiodes 66, 67 and 70 provide the control in FIG. 3. The gain control of PMT 20 is in the range from 100% to less than 0.001% (100,000 to 1).
    Type: Grant
    Filed: January 20, 1988
    Date of Patent: April 11, 1989
    Assignee: Vigyan Research Associates, Inc.
    Inventor: Robert J. Allen
  • 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: 4776542
    Abstract: A system for deterring subsonic airplane stall-spin entry wherein a highly swept wing tip mounted lifting surface panel 18 (FIGS. 1-3) is attached to the tip of a main wing panel 14 and provides a stabilizing vortex lift to the aircraft at an angle of attack slightly greater than the normal angle of attack used in climbing flight. This vortex lift enhances roll damping at high angles of attack and serves to prevent airplane stall-spin entry. FIG. 4 shows an alternate form of the invention wherein the wing tip mounted lifting surface panel 48 is provided with a forward highly swept leading edge. For sharp leading edges a leading edge sweep for the wing tip mounted lifting surfaces is approximately forty-five degrees while, for blunt leading edge surfaces, a greater degree of sweep is employed to generate the vortex lift.
    Type: Grant
    Filed: May 27, 1987
    Date of Patent: October 11, 1988
    Assignee: Vigyan Research Associates, Inc.
    Inventor: Cornelis P. Van Dam