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:
Nov. 15, 1994
Filed:
Sep. 02, 1993
Richard A Katz, East Lyme, CT (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A method of detecting the onset of turbulence in connection with a body mng through a fluid medium and of reducing body drag and as well reducing the amount of drag noise radiated from the body. First, the body is supplied with sensors each for generating a signal suitable for measuring amplitude of pressure fluctuations of the medium proximate a region of said sidewall of the body in at least a region of the body in which turbulence is expected to occur. During a reference stage during which the body moves through the fluid medium when it is known that turbulence is occurring around at least a portion of said body, the sensors each generate reference temporal pressure data representing fluctuations in pressure of the fluid medium around said body. In response to reference temporal pressure data generated by sensors in a turbulence zone at which turbulence is occurring and sensors in a transition zone between the turbulence zone and a laminar flow zone, method-of-delay phase portraits are generated for a progression of selected delay intervals. During an operational stage, the signals from the sensors are filtered to generate a portion representing the turbulence due to motion of the body through the medium and a portion representing signals from external acoustic signal sources, and the turbulence signal portion is used to generate signals of appropriate phase which are injected into the medium to reduce the turbulence noise signals and thereby reduce drag on the body due to the medium.