University of Southampton OCS (beta), RASD 2013 11th International Conference on Recent Advances in Structural Dynamics 1st – 3rd July 2013

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RECENT ENHANCEMENTS TO THE NASA LANGLEY STRUCTURAL ACOUSTICS LOADS AND TRANSMISSION (SALT) LABORATORY
Stephen A Rizzi, Randolph H Cabell, Albert R Allen

Last modified: 2013-04-19

Abstract


The Structural Acoustics Loads and Transmission (SALT) laboratory [1] at the NASA Langley Research Center is comprised of an anechoic chamber and a reverberant chamber, and may act as a transmission loss suite when test articles are mounted in a window connecting the two chambers. In the latter configuration, the reverberant chamber acts as the noise source side and the anechoic chamber as the receiver side. In either configuration, the noise generation system was previously shown to achieve a maximum overall sound pressure level of 141 dB [2]. This is considered to be marginally adequate for generating sound pressure levels typically required for launch vehicle payload qualification testing. Recent enhancements to the noise generation system increased the maximum overall sound pressure level to 154 dB. This paper will document the acoustic performance of the enhanced noise generation system for a variety of relevant test spectra. Additionally, it will demonstrate the capability of the SALT laboratory to conduct transmission loss and absorption testing in accordance with ASTM [3] and ISO [4] standards, respectively. Results from a transmission loss test of a new hybrid wing-body fuselage concept will be shown to demonstrate that capability [5].


References


[1] Grosveld, F.W., "Calibration of the Structural Acoustics Loads and Transmission Facility at NASA Langley Research Center," Inter-Noise, pp. 6, Fort Lauderdale, FL, 1999.

[2] Grosveld, F.W. and Rizzi, S.A., "Controlled reverberant acoustic excitation capabilities at NASA Langley Research Center," Proceedings of the 43rd AIAA Aerospace Sciences Meeting, AIAA-2005-0421, Reno, NV, January 10-13, 2005.

[3] ASTM, "Standard test method for laboratory measurement of airborne transmission loss of building partitions and elements using sound intensity," E2249-02, 2008.

[4] ISO, "Measurement of sound absorption in a reverberation room," ISO 354, 2003.

[5] Allen, A.R. and Przekop, A., "Vibroacoustic characterization of a new hybrid wing-body fuselage concept," Proceedings of the Internoise 2012/ASME NCAD meeting, IN12-321, New York, NY, 2012.


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