The Mixing Transition in Free Shear Flows

  • Anatol Roshko
Part of the NATO ASI Series book series (NSSB, volume 268)


The term “mixing transition” denotes an increase in molecular mixedness observed in a shear flow which has earlier experienced the conventional (momentum) transition from laminar flow. First defined by Konrad (1976), from measurements of concentration in a free shear layer, the transition has been described and measured by a number of other methods, in particular by flow visualiztion, by measurement of chemical reaction product and by hot-wire anemometry, in aqueous as well as gaseous flows. In this presentation we review some of the measurements and try to assess what insight they may give on several questions that occur. 1. What is the relation of the mixing transition to Reynolds number and to other events: the momentum transition; vortex pairing; development of streamwise vortex structure? 2. How much does interfacial area increase during the transition? 3. How fast does this occur? 4. Does chaotic advection play a role? The answers are tentative and incomplete.


Reynolds Number Shear Layer Vortex Structure Vortex Pairing Streamwise Vortex 
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  1. Aref, H. and Jones, S. W., 1989, Enhanced separation of diffusing particles by chaotic advection. Phys. Fluid A 1: 470.MathSciNetADSzbMATHCrossRefGoogle Scholar
  2. Bernal, L. P., 1981, Streamwise vortex structure in plane mixing layers, Ph. D. thesis, Calif. Inst. of Technology; also with A. Roshko, J. Fluid Mech. 1986, 170: 499.Google Scholar
  3. Bradshaw, P., 1966, The effect of initial conditions in the development of a free shear layer, J. Fluid Mech. 26: 225.ADSCrossRefGoogle Scholar
  4. Breidenthal, R. E., 1978, A chemically reacting, turbulent shear layer, Ph. D. thesis, Calif. Inst. of Technology; also J. Fluid Mech. 1981, 109: 1.Google Scholar
  5. Brown, G. and Roshko, A., 1974, On density effects and large structure in turbulent mixing layers, J. Fluid Mech. 64: 775.ADSCrossRefGoogle Scholar
  6. Corcos, G. M., 1979, The mixing layer: deterministic models of a turbulent flow, Univ. California Berkeley Rept. No. FM-79–2; also Corcos, G. M. and Sherman, F. S., 1984, J. Fluid Mcch: 29.Google Scholar
  7. Freymuth, P., 1966, On transition in a separated laminar boundary layer, J. Fluid Mech. 25: 683.ADSCrossRefGoogle Scholar
  8. Ho, C-M. and Huerre, P., 1984, Perturbed free shear layers, Ann. Rev. Fluid Mech. 16: 365.ADSCrossRefGoogle Scholar
  9. Huang, L.-S. and Ho, C.-M., 1990, Small-scale transition in a plane mixing layer, J. Fluid Mech. 210: 475.ADSCrossRefGoogle Scholar
  10. Hussain, A. K. M. Fazle, 1986, Coherent structures and turbulence, J. Fluid Mech. 173: 303.ADSCrossRefGoogle Scholar
  11. Jimenez, J., 1983, A spanwise structure in the plane shear layer, J. Fluid Mech. 132: 319.ADSCrossRefGoogle Scholar
  12. Jimenez, J., Martinez–Val, R. and Rebollo, M., 1979, On the origin and evolution of three dimensional effects in the mixing layer, USA–ERO Rep. 79–6–079, London.Google Scholar
  13. Konrad, J. H., 1977, An experimental investigation of mixing in two dimensional turbulent shear flows with application to diffusion-limited chemical reactions, Ph. D. thesis, California Institute of Technology.Google Scholar
  14. Koochesfahani, M. M., 1984, Experiments on turbulent mixing and chemical reaction in a liquid mixing layer, Ph. D. thesis, Calif. Inst. of Technology; also, with P. E. Dimotakis, J. Fluid Mech. 1986, 170: 83.Google Scholar
  15. Lin, S. J. and Corcos, G. M., 1984, The mixing layer: deterministic models of a turbulent flow. Part 3. The effect of plane strain on the dynamics of streamwise vortices, J. Fluid Mech. 141: 139.ADSzbMATHCrossRefGoogle Scholar
  16. Lundgren, T. S., 1982, Strained spiral vortex model for turbulent fine structure, Phys. Fluids, 25: 2193.ADSzbMATHCrossRefGoogle Scholar
  17. Michalke, A., 1965, Spatially growing disturbances in an inviscid shear layer, J. Fluid Mech. 23: 521.MathSciNetADSCrossRefGoogle Scholar
  18. Rom-Kedar, A., Leonard, A. and Wiggins, S., 1990, An analytical study of transport, mixing and chaos in an unsteady vortical flow, J. Fluid Mech. 214: 347.MathSciNetADSzbMATHCrossRefGoogle Scholar
  19. Roshko, A., 1981, The plane mixing layer: flow visualization results and three dimensional effects, in Lecture Notes in Physics No. 136 ( The Role of Coherent Structures in Modelling Turbulence and Mixing, J. Jimenez, ed. ), Springer.Google Scholar
  20. Sato, H., 1956, Experimental investigation on the transition of laminar separated layer, J. Phys. Soc. Japan 11: 702.ADSCrossRefGoogle Scholar
  21. Zohar, Y., 1990, Fine-scale mixing in a free shear layer. Ph. D. dissertation, Univ. Southern California.Google Scholar

Copyright information

© Springer Science+Business Media New York 1991

Authors and Affiliations

  • Anatol Roshko
    • 1
  1. 1.California Institute of TechnologyPasadenaUSA

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