Hostname: page-component-76fb5796d-2lccl Total loading time: 0 Render date: 2024-04-27T01:54:12.791Z Has data issue: false hasContentIssue false

A phase-equation approach to boundary–layer instability theory: Tollmien-Schlichting waves

Published online by Cambridge University Press:  26 April 2006

Philip Hall
Affiliation:
Department of Mathematics, University of Manchester, Manchester M13 9PL, UK

Abstract

Our concern is with the evolution of large-amplitude Tollmien-Schlichting waves in boundary-layer flows. In fact, the disturbances we consider are of a comparable size to the unperturbed state. We shall describe two-dimensional disturbances which are locally periodic in time and space. This is achieved using a phase equation approach of the type discussed by Howard & Kopell (1977) in the context of reaction-diffusion equations. We shall consider both large and O(1) Reynolds number flows though, in order to keep our asymptotics respectable, our finite-Reynolds-number calculation will be carried out for the asymptotic suction flow. Our large-Reynolds-number analysis, though carried out for Blasius flow, is valid for any steady two-dimensional boundary layer. In both cases the phase-equation approach shows that the wavenumber and frequency will develop shocks or other discontinuities as the disturbance evolves. As a special case we consider the evolution of constant frequency/wavenumber disturbances and show that their modulational instability is controlled by Burgers equation at finite-Reynolds-number and by a new integro-differential evolution equation at large-Reynolds-numbers. For the large Reynolds number case the evolution equation points to the development of a spatially localized singularity at a finite time.

Type
Research Article
Copyright
© 1995 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Brotherton-Ratcliffe, R. V. & Smith, F. T. 1987 Mathematika 34, 86.
Conlisk, A. T., Burcxjraf, O. R., Smith, F. T. 1987 Trans. ASME FED, vol. 52, p. 119.
Cross, M. & Newell, A. C. 1984 Physica D 10, 299.
Davey, A., Hocking, L. M. & Stewartson, K. 1974 J. Fluid Mech. 63, 529.
DiPRiMA, R. C. & Stuart, J. T. 1975 J. Fluid Mech. 67, 85.
Gaster, M. 1974 J. Fluid Mech. 66, 465.
Hall, P. 1988 J. Fluid Mech. 193, 243.
Hall, P. & Smith, F. T. 1984 Stud. Appl. Maths 70, 91.
Herbert, T. 1977 AGARD Conf. Proc. CP 224, 3/1-10.Google Scholar
Howard, L. & Kopell, N. 1977 Stud. Appl. Maths 56, 95.
Hocking, L. M. 1975 Q. J. Mech. Appl. Maths 28, 341.
Kachanov, Yu. S. & Levchenko, V. Yu 1984 J. Fluid Mech. 138, 209.
Khokhlov, A. P. 1994 J. Appl. Maths Tech. Phys. 34, 508.
Klebanoff, P. S., Tidstrom, K. D. & Sargent, L. M. 1962 J. Fluid Mech. 12, 1.
Kramer, L., Ben Jacob, E., Brand, H. & Coss, M. C. 1982 Phys. Rev. Lett. 49, 1891.
Lin, C. C. 1966 The Theory of Hydrodynamic Stability. Cambridge University Press.
Newell, A. C., Passot, T. & Lega, J. 1993 Ann. Rev. Fluid Mech. 25, 399.
Papageorgiu, D. T. & Smyrlis, Y. S. 1991 Proc. Natl Acad. Sci. USA, 24, 11129.
Smith, F. T. 1973 J. Fluid Mech. 57, 803.
Smith, F. T. 1979a Proc. R. Soc. Lond. A 366, 91.
Smith, F. T. 1979 Proc. R. Soc. Lond. A 368, 513.
Smith, F. T. & Burggraf, O. R. 1985 Proc. R. Soc. Lond. A 399, 25.
Smith, F. T. & Stewart, P. 1987 J. Fluid Mech. 194, 21.
Whitham, G. B. 1974 Linear and Nonlinear Waves. Wiley.
Wray, A. A. & Hussaini, M. Y. 1984 Proc. R. Soc. Lond. A 392, 373.
Zhuk, V. I. & Ryzhov, O. S. 1982 Sov. Phys. Dokl. 27, 177.