A parametric study of fine-scale turbulence mixing noise

Abbas Khavaran, James Bridges, Jonathan Freund

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The present paper is a study of aerodynamic noise spectra from model functions that describe the source. The study is motivated by the need to improve the spectral shape of the MGBK jet noise prediction methodology at high frequency. The predicted spectral shape usually appears less broadband than measurements and faster decaying at high frequency. Theoretical representation of the source is based on Lilley's equation. Numerical simulations of high-speed subsonic jets as well as some recent turbulence measurements reveal a number of interesting statistical properties of turbulence correlation functions that may have a bearing on radiated noise. These studies indicate that an exponential spatial function may be a more appropriate representation of a two-point correlation compared to its Gaussian counterpart. The effect of source non-compactness on spectral shape is discussed. It is shown that source non-compactness could well be the differentiating factor between the Gaussian and exponential model functions. In particular, the fall-off of the noise spectra at high frequency is studied and it is shown that a non-compact source with an exponential model function results in a broader spectrum and better agreement with data. A recent source model proposed by Tam et al. that represents the source as a covariance of the convective derivative of fine-scale turbulence kinetic energy is also examined.

Original languageEnglish (US)
Title of host publication8th AIAA/CEAS Aeroacoustics Conference and Exhibit
StatePublished - Dec 1 2002
Event8th AIAA/CEAS Aeroacoustics Conference and Exhibit, 2002 - Breckenridge, CO, United States
Duration: Jun 17 2002Jun 19 2002

Publication series

Name8th AIAA/CEAS Aeroacoustics Conference and Exhibit

Other

Other8th AIAA/CEAS Aeroacoustics Conference and Exhibit, 2002
CountryUnited States
CityBreckenridge, CO
Period6/17/026/19/02

ASJC Scopus subject areas

  • Aerospace Engineering
  • Electrical and Electronic Engineering
  • Mechanical Engineering
  • Acoustics and Ultrasonics

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