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Experimental Probability Density Functions of a Passive Scalar in a Turbulent Görtler Flow and Comparison with the Pope and Ching Model

  • J. L. Aider
  • J. E. Wesfreid
Part of the Fluid Mechanics and its Applications book series (FMIA, volume 36)

Abstract

In this communication we are interested in the experimental study of the mixing of a non-reacting passive scalar in an hydrodynamic turbulent flow in a curved channel (turbulent Görtler flow). We used Laser Induced Fluorescence technique [1] to visualize and analyze quantitatively the effect of the geometry and of the Reynolds number on the statistics of the concentration time series. The Fig. 1 is a visualization of the turbulent flow in a cross-section of the curved channel (60° from the leading edge) and we show the four regions corresponding to the different instabilities involved in the production of vortical structures:
  • Görtler instability in the boundary layer over the concave wall (region I).

  • Ekman cells in the comer of the duct (region II).

  • detaching of the boundary layer under the convex wall (region III).

  • homogenous mixing region in the middle of the cross-section (region IV).

Keywords

Boundary Layer Reynolds Number Vortical Structure Passive Scalar Conditional Average 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. [1]
    J. L. Aider and J. E. Wesfreid, “Visualizations and PDFs of fluctuations of concentration”, in Experimental and Numerical Flow visualization, A.S.M.E. FED-Vol 218, Book no. G00968, 123–130 (1995)Google Scholar
  2. [2]
    S. Balachandar and L. Sirovich, Probability Distribution Functions in turbulent Convection ICASE Report No. 91–17(1991).Google Scholar
  3. [3]
    E. S. C. Ching and S. Pope, “Stationnary Probability Density Functions: an exact result”, Phys. of Fluids A, 7, 1529 (1993)Google Scholar

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • J. L. Aider
    • 1
  • J. E. Wesfreid
    • 1
  1. 1.Laboratoire de Physique et de Mécanique des Milieux Hétérogènes, URA CNRS 857Ecole Supérieure de Physique et de Chimie IndustriellesParisFrance

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