research on sound absorption properties of variable aperture micro-perforated panel in spacecraft

Paper number

IAC-08.C2.1.6

Author

Mr. Linling Li, CAST, China

Year

2008

Abstract

Spacecraft working area noise level is 58 dB(A) stipulated by NASA. Refrigeration fan, compressor, pump etc. continuous revolving equipment of manned spacecraft, international space station, space shuttle emit buzz noise. The buzz noise goes beyond the criterion. The environment noise of overstepping the criterion affects astronaut home-felt comfortable and security badly from physiology and psychology. At present, fibre material and foam material using in spacecraft arrive at the noise controlling effect of the NASA criterion difficultly. Taking into account sound absorption material weight, cost, sound absorption effective etc. synthetically, a new kind of spacecraft sound absorption structure satisfies the imminence request of spacecraft environment noise.
The noise frequency characteristic (high intensity noise, low frequency etc.) of spacecraft environment noise analyses are presented. Based on the micro-perforated panel sound absorption structure wideband absorbing characteristic, used the general theory and design of micro-perforated panel sound absorption structure on basis of the acoustics and electricity equivalent circuit, a sound absorption structure of variable aperture micro-perforated panel is studied in this paper. The sound absorption properties and mechanism of the structure in outer-space environment (weightlessness, long reverberation time) are analyzed. The sound absorption structure, absorbing characteristic parameter (perforate constant, the cavity depth etc.) and its design method are obtained. It fits to using in outer-space environment. 
The new type structure (variety aperture micro-perforated panel) has high sound absorption coefficient of low frequency, wideband absorbing characteristic and well & truly satisfied the designing request etc. The structure can decrease the environment noise of spacecraft consumedly. Astronaut can finish the science research task effectively in a good outer-space life surrounding for a long time.

Abstract document

IAC-08.C2.1.6.pdf

Manuscript document

IAC-08.C2.1.6.pdf (🔒 authorized access only).

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