Unsteady, Separated Laminar Flow in Non-Uniform Vessels

  • T. J. Pedley
  • M. E. Ralph
  • O. R. Tutty
Conference paper


Regions of flow separation appear to be important sites for athero-genesis. Here we show that flow unsteadiness, even at low frequencies, has a significant effect on the location of and wall shear stress in separated eddies. Experimental and computational results are presented for (i) flow past a time-dependent, asymmetric indentation in a two-dimensional channel, and (ii) oscillatory flow through a fixed expansion. Trains of vorticity waves are observed downstream of the indentation or expansion, each wave associated with a separated eddy which somtimes itself divides into two. The wall shear stress in the eddies is much larger than in steady or parallel flow. Also, in each case the flow eventually becomes three-dimensional.


Wall Shear Stress Strouhal Number Oscillatory Flow Plane Wall Flow Unsteadiness 
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Copyright information

© Springer-Verlag Tokyo 1988

Authors and Affiliations

  • T. J. Pedley
    • 1
  • M. E. Ralph
    • 1
  • O. R. Tutty
    • 2
  1. 1.Department of Applied Mathematics and Theoretical PhysicsUniversity of CambridgeCambridgeEngland
  2. 2.Department of Aeronautics and AstronauticsUniversity of SouthamptonSouthamptonEngland

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