Direct and Large Eddy Simulation of Separated Turbulent Boundary Layers.

Abstract

Space-time characteristics of pressure fluctuations were analyzed using the databases generated from the direct numerical simulation. In the separated flow, the wall-pressure fluctuations are significantly reduced in the separation zone. However, they are significantly enhanced in the reattachment region. The streamwise and spanwise vorticities are lifted away from the wall in the separation zone and the pressure fluctuations are significantly enhanced in this shear layer. The contours of space-time correlations show that the convection velocities of wall-pressure fluctuations are reduced significantly inside the separation bubble. The reattachment region is characterized by large scale structures which are formed in the shear layer above the separation bubble. Frequency spectra downstream of incipient detachment shows that maximum turbulent shearing stress appears to be the proper scale to normalize wall-pressure fluctuations in the turbulent boundary layers in the presence of large adverse pressure gradient. (AN)

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1995
Accession Number
ADA294531

Entities

People

  • Parviz Moin

Organizations

  • Stanford University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Computational Fluid Dynamics
  • Convection
  • Dynamic Pressure
  • Experimental Data
  • Fluid Dynamics
  • Fluid Mechanics
  • Free Stream
  • Large Eddy Simulation
  • Mechanical Engineering
  • Pressure Gradients
  • Reynolds Number
  • Skin Friction
  • Three Dimensional
  • Turbulent Boundary Layer
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster