Method and apparatus for reducing drag on a moving body
OwnerDavid A. Bassett, Marlin R. Bassett +1inventors
InventorsDavid A. Bassett, Marlin R. Bassett, John C. Schroeder
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Abstract
A method of and apparatus for reducing drag produced by relative air movement on a moving body are disclosed. The method includes the steps of modifying a rear air pressure behind a rear of the body such that the rear air pressure is increased, wherein the air pressure modifying step includes inletting an amount of air from a boundary flow around the body and forming a pressure shell behind the rear of the body, wherein the pressure shell forming step includes forming a large vortex behind the rear of the body by outletting the inlet air at the rear of the body in a plurality of small high-energy vortices.
Claims48
A method of reducing drag produced by relative air movement on a moving, non-lifting bluff body, said body having a front end and a rear end, wherein said body has a substantially closed surface at its rear end, wherein said body is an entire moving system, comprising of steps of:
- modifying a rear air pressure behind a rear of said body such that said rear air pressure is increased, said air pressure modifying step including
- inletting an amount of air from a boundary flow around said body, and
- forming a pressure shell behind said rear of said body, said pressure shell forming step including forming a large vortex behind said rear of said body by outletting said inlet air at said rear of said body in a plurality of small high-energy vortices of one sense of rotation, which combine to titan a large vortex of one sense of rotation behind said entire moving system.
An apparatus for reducing drag on a moving body, comprising:
- a controller;
- at least one sensor for sensing a pressure and yaw angle of a relative air movement, an output of said sensor being connected to said controller;
- at least one air inlet for inletting air;
- a plurality of thrust augmenters connected to said air inlet;
- and
- at least one valve connected between said air inlet and said plurality of thrust augmenters, said controller being connected to said valve to control a rate of air flow through said valve in response to said output of said sensor.
An apparatus for reducing drag on a moving non-lifting bluff body, said body having a front end and a rear end, wherein said body has a substantially closed surface at its rear end, wherein said body is an entire moving system, comprising:
- means for inletting an amount of air from a boundary layer flow;
- and
- means for forming a pressure shell, said pressure shell forming means including means for forming a plurality of small high-energy vortices of the same sense of rotation, which combine to form a large vortex of one sense of rotation behind said entire moving system, said small vortex forming means including
- means for outletting said inlet air, and
- means for entraining a portion of the boundary lawyer flow with said inlet air.
An apparatus for reducing drag on a moving body, comprising:
- at least one inlet mounted on a forward portion of said body;
- a plurality of thrust augmenters mounted on a rear portion of said body;
- at least one duct mounted on said body and connecting said inlet with said thrust augmenters,
- at least one valve in said duct;
- a pair of sensors mounted on said body to sense a pressure and a yaw angle of a relative air movement on said body;
- and
- a controller connected to said sensors and said valve to control said valve and thus an air flow rate through said thrust augmenters, based on outputs of said sensors.
A thrust augmenter, comprising:
- a circular venturi;
- a nozzle mounted rotatably within said venturi;
- and
- a backflow redirector mounted around an upstream end of said nozzle, said backflow redirector including means for redirecting upstream-directed leakage from said nozzle downstream around an outer surface of said nozzle.
Dependencies are inferred from the claim text.