Rigid foraminous microphone probe for acoustic measurement in turbulent flow
US4903249A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1988 |
| Grant date | Feb 20, 1990 |
| Priority date | — |
| Expiry date | Mar 24, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01H3/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A microphone probe for acoustic measurement in turbulent flow. The probe includes a tube having a closed end facing upstream with respect to the direction of sound propagation and a microphone is located in a downstream end of the tube. At least a portion of the length of the tube is composed of a rigid foraminous material containing a multiplicity of interconnected cells with the average cell size being less than 100 microns. In operation sound pressure fluctuations cause pressure waves to propagate through the cells to the inside of the tube and the sound pressure waves add constructively to create a high pressure sound at the microphone, while turbulent flow pressure fluctuations are essentially averaged out.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.