Sandy Ming Liu

US Patent:

56847564, Nov 4, 1997

Filed:

Jan 22, 1996

Appl. No.:

8/589671

Inventors:

Fredric Schmitz - Palo Alto CA
Sandy Liu - Cupertino CA
Stephen Jaeger - Sunnyvale CA
W. Clifton Horne - San Jose CA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

H04R 102

US Classification:

367188

Abstract:

An acoustic sensor assembly is provided for sensing acoustic signals in a moving fluid such as high speed fluid stream. The assembly includes one or more acoustic sensors and a porous, acoustically transparent screen supported between the moving fluid stream and the sensor and having a major surface disposed so as to be tangent to the moving fluid. A layer of reduced velocity fluid separating the sensor from the porous screen. This reduced velocity fluid can comprise substantially still air. A foam filler material attenuates acoustic signals arriving at the assembly from other than a predetermined range of incident angles.