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Shock Induced Flow Oscillations in a Laval Nozzle

  • G. E. A. Meier
Part of the International Union of Theoretical and Applied Mechanics book series (IUTAM)

Summary

The physical system consisting of a shock wave and the downstream separated flow causes oscillatory instabilities in a Laval nozzle flow. The shock-boundary layer interaction creates or displaces a separation bubble, thereby changing the flow field downstream of the shock root. This process usually strengthens the shock wave by increasing the back pressure. The shock wave then becomes unsteady, moving the separation point with it in an upstream direction, so that a self-preserving instability occurs, thus reducing the flow velocity in the whole transonic field. By means of the later reattachment of the boundary layer, the entire flow is accelerated and tends to return to the initial condition, i.e., the process is cyclic. The length of the oscillation periods can be estimated. Using a one-dimensional model for the Laval nozzle flow, it can actually be calculated. Consideration of the gasdynamics of the process leads to limits in terms of pressure or Mach number for the existence of oscillations, these limits being in good agreement with experimental results.

Keywords

Shock Wave Mach Number Back Pressure Separation Point Separation Bubble 
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.

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References

  1. 1.
    Meier, G.; Hiller, W.: An Experimental Investigation of Unsteady Transonic Flow by High-Speed Interferometric Photography. AGARD CP 35 (1968) 1–9.Google Scholar
  2. 2.
    Pearcy, H.H.; Holder, D.W.: Simple Methods for the Prediction of Wing Buffeting Resulting from Bubble Type Separation. NPL Aero Rep. 1024 (1962).Google Scholar
  3. 3.
    Meier, G.E.A.: Ein instationäres Verhalten transsonischer Strömungen. Mitt. MPI/AVA Nr. 59 (1974).Google Scholar
  4. Meier, G.E. A.: Shock Induced Flow Oscillations. AGARD CP 168 (1975) 1–9.Google Scholar
  5. 4.
    Trilling, L.: Oscillating Shock Boundary-Layer Interaction. Journ. Aero Sci. Vol. 25, No. 5 (1958).Google Scholar

Copyright information

© Springer-Verlag, Berlin/Heidelberg 1976

Authors and Affiliations

  • G. E. A. Meier
    • 1
  1. 1.Max-Planck-Institut für StrömungsforschungD 34 GöttingenGermany

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