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Ray Traces Through Unsteady Jet TurbulenceResults of an ongoing effort to quantify the role turbulence in scattering sound in jets are reported. Using a direct numerical simulation database to provide the flow data, ray paths traced through the mean flow are compared with those traced through the actual time evolving turbulent flow. Significant scattering by the turbulence is observed. The most notable effect is that upstream traveling waves that are trapped in the potential core by the mean flow, which acts as a wave guide, easily escape in the turbulent flow. A crude statistical estimate based on ray number density suggests that directivity is modified by the turbulence, but no rigorous treatment of non-uniformities in the high-frequency approximation is attempted.
Document ID
20020048661
Acquisition Source
Headquarters
Document Type
Other
Authors
Freund, J. B. (Illinois Univ. Urbana-Champaign, IL United States)
Fleischman, T. G. (California Univ. Los Angeles, CA United States)
Date Acquired
September 7, 2013
Publication Date
January 1, 2002
Subject Category
Fluid Mechanics And Thermodynamics
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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