Molecular Mixing in Shear Layers Forced by 2-D and 3-D Disturbances.

Abstract

Experiments on 2-D forcing of shear layers were completed. Analysis of data from two different forcing techniques have revealed that much of the global aspects of the scalar mixing field appear to exhibit a universal behavior in terms of the non-dimensional downstream distance x * = x Xf/ Uc where X = (U1 -U2)/(U1 +U2) and Uc = (U1 +U2)/2. This universal behavior suggests that the total amount of mixing per unit width of the layer is enhanced in regions where x* > 1.5. Work on 3-D forcing and combined 2-D/3-D forcing has lead to new findings. Results show that high amplitude 2-D forcing of a low Reynolds number wake can lead to a dramatic increase in mixing due to 3-D interaction of the vorticity field with the test section side walls. The possible application of this finding to mixing enhancement at higher Reynolds numbers is being investigated. Experiments on shear layers forced by a localized 3-D perturbation at the splitter plate along with 2-D forcing have shown that it is possible to significantly alter not only the predominant mixed-fluid composition but also the actual pdf structure (e.g. non-marching and marching behavior). Preliminary results suggest that the behavior of the span-averaged total mixing is similar to the case of purely 2-D forcing. (AN)

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Document Details

Document Type
Technical Report
Publication Date
Oct 26, 1994
Accession Number
ADA290272

Entities

People

  • Manoochehr M. Koochesfahani

Organizations

  • Michigan State University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Amplitude
  • Boundary Layer
  • Chemical Products
  • Chemical Reactions
  • Data Analysis
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Mechanics
  • Intensity
  • Laser Induced Fluorescence
  • Lasers
  • Mechanical Phenomena
  • Mechanics
  • Reynolds Number
  • Three Dimensional
  • Turbulent Mixing
  • Two Dimensional

Readers

  • Analytical Mechanics
  • Fluid Mechanics and Fluid Dynamics.