scholarly journals Application of MEMS Microphone Array Technology to Airframe Noise Measurements

2005 ◽  
Author(s):  
William Humphreys ◽  
Qamar Shams ◽  
Sharon Graves ◽  
Bradley Sealey ◽  
Scott Bartram ◽  
...  
Keyword(s):  
Microphone Array ◽  
Airframe Noise ◽  
Array Technology ◽  
Mems Microphone ◽  
Noise Measurements

Airframe noise measurements on JAXA Jet Flying Test Bed “Hisho” using a phased microphone array

2017 ◽  
Vol 16 (4-5) ◽  
pp. 255-273 ◽  
Author(s):  
Takehisa Takaishi ◽  
Hiroki Ura ◽  
Kenichiro Nagai ◽  
Yuzuru Yokokawa ◽  
Mitsuhiro Murayama ◽  
...  
Keyword(s):  
Microphone Array ◽  
Low Frequency ◽  
Landing Gear ◽  
Frequency Resolution ◽  
Test Bed ◽  
Noise Sources ◽  
Low Frequencies ◽  
Airframe Noise ◽  
Noise Measurements ◽  
Wooden Platform

In 2015, the Japan Aerospace Exploration Agency launched the Flight demonstration of QUiet technology to Reduce nOise from High-lift configurations project to verify by flight demonstration the feasibility of practical noise-reducing aircraft modification concepts. In order to serve as a baseline for comparison before modification, airframe noise sources of the JAXA Jet Flying Test Bed “Hisho” were measured with a 30 m diameter array of 195 microphones mounted on a wooden platform built temporary beside the runway of Noto Satoyama Airport in Japan. A classical Delay and Sum in the time domain beamforming algorithm was adapted for the present study, with weight factors introduced to improve the low-frequency resolution and autocorrelations eliminated to suppress wind noise at high frequencies. In the landing configuration at idle thrust, the main landing gear, nose landing gear, and side edges of the six extended flap panels were found to be the dominant “Hisho” airframe noise sources. Deconvolution by the DAMAS and CLEAN-SC algorithms provided clearer positions of these sound sources at low frequencies. Integration of acoustical maps agreed well with the sound pressure level measured by a microphone placed at the center of the microphone array and gave detailed information about the contribution of each noise source.

Development of MEMS microphone array technology for aeroacoustic testing

2004 ◽  
Vol 116 (4) ◽  
pp. 2511-2511
Author(s):  
Qamar A. Shams ◽  
Sharon S. Graves ◽  
Scott M. Bartram ◽  
Bradley S. Sealey ◽  
Toby Comeaux
Keyword(s):  
Microphone Array ◽  
Array Technology ◽  
Mems Microphone

Airframe noise measurements in a large hard-walled closed-section wind tunnel

2019 ◽  
Vol 146 ◽  
pp. 96-107 ◽  
Author(s):  
Alessandro Di Marco ◽  
Lorenzo Burghignoli ◽  
Francesco Centracchio ◽  
Roberto Camussi ◽  
Thomas Ahlefeldt ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Airframe Noise ◽  
Noise Measurements

scholarly journals ON EFFICIENCY OF SOME METHODS FOR DETERMINING THE AZIMUTHAL STRUCTURE OF NOISE IN CYLINDRICAL DUCT

Akustika ◽  
2019 ◽  
Vol 32 ◽  
pp. 130-134
Author(s):  
Vadim Palchikovskiy ◽  
Yuliy Bersenev ◽  
Ivan Korin
Keyword(s):  
Least Squares ◽  
Dynamic Range ◽  
Least Squares Method ◽  
Microphone Array ◽  
Aircraft Engine ◽  
Circular Array ◽  
Noise Measurements ◽  
Air Intake ◽  
Experimental Values ◽  
Cylindrical Duct

The determination of azimuthal sound modes propagating in a cylindrical duct is considered based on the results of noise measurements on experimental setup with a duct diameter of 1.8 m, which corresponds to the air intake of aircraft engine. The experiments were carried out in PNRPU anechoic chamber. Spinning modes were generated by a circular array of 40 acoustic drivers. Noise in duct was recorded with circular array of 100 microphones with optimized arrangement to reach maximum dynamic range. The following methods for determining the azimuthal structure of noise were compared: modal decomposition method, cross-correlation with a reference channel method; least-squares method. The mathematical foundations and specifics of these methods are briefly outlined. According to the results of the azimuthal structure extraction, it was found that the least-squares method provides the best agreement between the generated and extracted modes and the distribution of the computed and experimental values of acoustic pressures on microphone array.

MEMS microphone intensity array for cabin noise measurements

2021 ◽  
Vol 263 (3) ◽  
pp. 3023-3034
Author(s):  
Carsten Spehr ◽  
Daniel Ernst ◽  
Hans-Georg Raumer
Keyword(s):  
Sound Intensity ◽  
Phase Match ◽  
Acoustic Energy ◽  
Low Frequencies ◽  
Cabin Noise ◽  
Noise Simulation ◽  
Mems Microphone ◽  
Noise Measurements ◽  
Mems Microphones ◽  
Absorbing Material

Aircraft cabin noise measurements in flight are used toto quantify the noise level, and to identify the entry point of acoustic energy into the cabin. Sound intensity probes are the state-of-the-art measurement technique for this task. During measurements, additional sound absorbing material is used to ease the rather harsh acoustic measurement environment inside the cabin. In order to decrease the expensive in-flight measurement time, an intensity array approach was chosen. This intensity probe consists of 512 MEMS-Microphones. Depending on the frequency, these microphones can be combined as an array of hundreds of 3D- intensity probes. The acoustic velocity is estimated using a high order 3D finite difference stencil. At low frequencies, a larger spacing is used to reduce the requirement of accurate phase match of the microphone sensors. Measurements were conducted in the ground-based Dornier 728 cabin noise simulation as well as in-flight.

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