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The stability of plane Poiseuille flow between flexible walls

Published online by Cambridge University Press:  29 March 2006

C. H. Green
Affiliation:
Imperial College, London Present address: The Nuclear Power Group, Radbroke Hall, Knutsford, Cheshire.
C. H. Ellen
Affiliation:
Imperial College, London

Abstract

This paper examines the linear stability of antisymmetric disturbances in incompressible plane Poiseuille flow between identical flexible walls which undergo transverse displacements. Using a variational approach, an approximate solution of the problem is formulated in a form suitable for computational evaluation of the (complex) wave speeds of the system. A feature of this formulation is that the varying boundary conditions (and the Orr-Sommerfeld equation) are satisfied only in the mean; this reduces the labour involved in determining the approximate solution for a variety of wall conditions without increasing the difficulty of obtaining solutions to a given accuracy. In this paper the symmetric stream function distribution across the channel is represented by a series of cosines whose coefficients are determined by the variational solution. Comparisons with previous work, both for the flexible-wall and rigid-wall problems, show that the method gives results as accurate as those obtained previously by other methods while new results, for flexible walls, indicate the presence of a higher wave-number stability boundary which joins the distorted Tollmien-Schlichting stability boundary at lower wave-numbers. In some cases this upper unstable region, which is characterized by large amplification rates, may determine the critical Reynolds number of the system.

Type
Research Article
Copyright
© 1972 Cambridge University Press

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References

Benjamin, T. B. 1960 Effects of a flexible boundary on hydrodynamic stability. J. Fluid Mech. 9, 513532.Google Scholar
Benjamin, T. B. 1964 Fluid flow with flexible boundaries. Proc. 11th Int. Cong. Appl. Mech. Germany, pp. 109128.
Finlayson, B. A. & Scriven, L. E. 1966 The method of weighted residuals – a. review. Appl. Mech. Rev. 19, 735748.Google Scholar
Green, C. H. 1970 The variational solution of the problem of plane Poiseuille flow with flexible walls. Ph.D. Thesis, Mathematics Dept., Imperial College, University of London.
Grosch, C. E. & Salwen, H. 1968 The stability of steady and time-dependent plane Poiseuille flow. J. Fluid Mech. 34, 177205.Google Scholar
Hains, F. D. & Price, J. F. 1962 Effect of a flexible wall on the stability of Poiseuille flow. Phys. Fluids, 5, 365.Google Scholar
Kaplan, R. E. 1964 The stability of laminar incompressible boundary layers in the presence of compliant boundaries. M.I.T. Aeroelastic and Structures Res. Lab., ASRLTR 116-1.
Landahl, M. T. 1962 On the stability of a laminar incompressible boundary layer over a flexible surface. J. Fluid Mech. 13, 609632.Google Scholar
Landahl, M. T. & Kaplan, R. E. 1965 The effect of compliant walls on boundary layer stability and transition. AGARDograph, 97, 363394.Google Scholar
Lee, L. H. & Reynolds, W. C. 1967 On the approximate and numerical solution of Orr-Sommerfeld problems. Quart. J. Math. Appl. Mech. 20, 122.Google Scholar
Lin, C. C. 1945 On the stability of two-dimensional parallel flows. Parts I, II, III. Quart. Appl. Math. 3, 117142, 218234, 277301.Google Scholar
Lin, C. C. 1955 The Theory of Hydrodynamic Stability. Cambridge University Press.