AIAA-2011-2890-pokora.pdf (9.49 MB)

Computational study of aero-acoustic sources in perforate silencers

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conference contribution
posted on 26.03.2012 by C.D. Pokora, Gary Page
Reynolds Averaged Navier Stokes and Large Eddy Simulations of two perforate plates at a overall pressure ratio of 1.45 have been performed to allow analysis of the sensitivity of acoustic noise sources to porosity. Two geometries are presented: A 23% porosity and a 40% porosity 1mm plate with 2mm diameter holes. Results presented in this paper show the initial jetlet and fully merged jet flow-field to be sensitive to the porosity and the presence of partial holes around the circumference of the plate. The increase in porosity reduces the available entrainment flow, and increases the local jetlet interaction and resultant turbulence levels. This interaction fundamentally changes the flow structure from coherent vortex rings (found at low porosity) to a helical structure. The 2nd and 4th order spatio- temporal correlation Rij and Rij,kl are presented as suggested validation data for acoustic source modeling together with far-field noise spectra obtained via a Ffowcs-Williams & Hawkings surface integral method.

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Aeronautical and Automotive Engineering

Citation

POKORA, C.D. and PAGE, G.J., 2011. Computational study of aero-acoustic sources in perforate silencers. 17th AIAA/CEAS Aeroacoustics Conference, 32nd AIAA Aeroacoustics Conference, Portland, Oregon, 5 - 8 June. AIAA 2011-2890.

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Published by the American Institute of Aeronautics and Astronautics, Inc. © the author(s)

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VoR (Version of Record)

Publication date

2011

Notes

This paper was presented at the 17th AIAA/CEAS Aeroacoustics Conference (32nd AIAA Aeroacoustics Conference) 5 - 8 June 2011, Portland, Oregon.

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en

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