The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 14, 1982
Filed:
Dec. 24, 1980
Seymour Edelman, Silver Spring, MD (US);
Other;
Abstract
Disclosed is a method and means to increase or decrease, on demand, the drag exerted by a fluid on a boundary. The boundary comprises a surface portion of a structure enclosing a moving fluid or may comprise a portion of the outer surface of an object moving through the fluid. Drag is varied by means of a set of piezoelectric sensors and an accompanying set of piezoelectric driver elements arranged in close proximity to one another at the boundary and electrically interconnected so that the pressure exerted by the moving fluid is sensed by one or more sensors and converted to an electrical signal which is then transformed into an electrical drive signal which is applied to one or more driver elements to cause a flexing of the driver element(s) in a predetermined direction so that drag is either reduced by moving the driver(s) away from the fluid or increased by moving the driver(s) towards the fluid. In the case of turbulent flow, drag is decreased by decreasing the pressure gradient in the fluid; that is, the drivers are moved away from the fluid in regions of high pressure and toward the fluid in regions of low pressure. The drag is increased by reversing these motions.