SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 43, ISSUE 13 - JULY 1, 2005

01 AERONAUTICS (GENERAL)
Includes general research topics related to manned and unmanned aircraft and the problems of flight within the Earth’s atmosphere.

Also includes manufacturing, maintenance, and repair of aircraft.

For specific topics in aeronautics, see categories 02 through 09.

For information related to space vehicles see 12 Astronautics.

20050182107 NASA Langley Research Center, Hampton, VA, USA

Application of MEMS Microphone Array Technology to Airframe Noise Measurements

Humphreys, William M., Jr.; Shams, Qamar A.; Graves, Sharon S.; Sealey, Bradley S.; Bartram, Scott M.; Comeaux, Toby; [2005]; 20 pp.; In English; 11th AIAA/CEAS Aeroacoustics Conference, 23-25 May 2005, Monterey, CA, USA Contract(s)/Grant(s): 23-781-10-10 Report No.(s): AIAA Paper 2005-3004; No Copyright; Avail: CASI; A03, Hardcopy

Current generation microphone directional array instrumentation is capable of extracting accurate noise source location and directivity data on a variety of aircraft components, resulting in significant gains in test productivity.

However, with this gain in productivity has come the desire to install larger and more complex arrays in a variety of ground test facilities, creating new challenges for the designers of array systems. To overcome these challenges, a research study was initiated to identify and develop hardware and fabrication technologies which could be used to construct an array system exhibiting acceptable measurement performance but at much lower cost and with much simpler installation requirements.

This paper describes an effort to fabricate a 128-sensor array using commercially available Micro-Electro-Mechanical System (MEMS) microphones. The MEMS array was used to acquire noise data for an isolated 26%-scale high-fidelity Boeing 777 landing gear in the Virginia Polytechnic Institute and State University Stability Tunnel across a range of Mach numbers. The overall performance of the array was excellent, and major noise sources were successfully identified from the measurements. Author

Airframes; Fabrication; Microelectromechanical Systems; Microphones; Noise Measurement; Wind Tunnel Stability Tests

Source: NASA.