Effect of a downstream ventilated gas cavity on the spectrum of turbulent boundary layer wall pressure fluctuations

Steven D. Young, Timothy A. Brungart, Gerald C. Lauchle

Research output: Contribution to conferencePaperpeer-review

1 Scopus citations

Abstract

This paper theoretically and experimentally examines the effect of a downstream ventilated gas cavity on the spectrum of turbulent boundary layer wall pressure fluctuations. The theoretical model predicts that the ratio of the point spectrum of the turbulent boundary layer wall pressure fluctuations upstream of a ventilated gas cavity to the blocked point pressure spectrum decays rapidly to zero as the cavity origin is approached and undergoes oscillations in amplitude that relax to unity as the quantityωx/U c goes to infinity upstream of the cavity. Here ω is the radian frequency, x is the distance upstream from the cavity origin and U c is the convection velocity. A water tunnel experiment was performed to investigate the theoretical predictions. Dynamic wall pressure sensors were mounted flush to the surface of a flat plate at various distances upstream from a rearward facing step. Carbon dioxide gas was injected into the separated flow region downstream of the step to form a ventilated cavity. The water tunnel measurements were unable to verify the reduction in the amplitude of the turbulent boundary layer wall pressure fluctuations as the step and cavity were approached but did verify the fundamental oscillation predicted by the theoretical model and its relaxation to unity as ωx/Uc went to infinity upstream of the step and cavity.

Original languageEnglish (US)
Pages143-149
Number of pages7
DOIs
StatePublished - Jan 1 2004
Event2004 ASME International Mechanical Engineering Congress and Exposition, IMECE - Anaheim, CA, United States
Duration: Nov 13 2004Nov 19 2004

Other

Other2004 ASME International Mechanical Engineering Congress and Exposition, IMECE
Country/TerritoryUnited States
CityAnaheim, CA
Period11/13/0411/19/04

All Science Journal Classification (ASJC) codes

  • Mechanical Engineering
  • Acoustics and Ultrasonics

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