Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-18T18:46:05.901Z Has data issue: false hasContentIssue false

Numerical simulations of the nonlinear kink modes in linearly stable supersonic slip surfaces

Published online by Cambridge University Press:  26 April 2006

Jeffrey A. Pedelty
Affiliation:
Department of Astronomy and Minnesota Supercomputer Institute, University of Minnesota, Minneapolis, MN 55455, USA
Paul R. Woodward
Affiliation:
Department of Astronomy and Minnesota Supercomputer Institute, University of Minnesota, Minneapolis, MN 55455, USA

Abstract

We have performed high-resolution numerical simulations of supersonic slip surfaces to confirm and illuminate earlier analytic nonlinear stability calculations of such structures. This analytic work was in turn inspired by earlier computer simulations reported in Woodward (1985) and Woodward et al. (1987). In particular Artola & Majda (1987) examined the response of a supersonic slip surface to an incident train of small-amplitude nonlinear sound waves. They found analytic solutions which indicate that nonlinear resonance occurs at three angles of incidence which depend upon the Mach number of the relative motion. The two-dimensional simulations described here numerically solve this problem for a Mach-4 flow using the piecewise-parabolic method (Colella & Woodward 1984; Woodward & Colella 1984). The simulations show that sound waves incident at a predicted resonance angle excite nonlinear behaviour in the slip surface. At these angles the amplitude of the reflected waves is much greater than the incident wave amplitude (i.e. a shock forms). The observed resonance is fairly broad, but the resonance narrows as the strength of the incident waves is reduced.

The nature of the nonlinear kink modes observed in the simulations is similar to that discussed by Artola & Majda. Most of the modes move in either direction with speeds near the predicted value. Speeds of other than this value are observed, but the disagreement is not serious in view of the strongly nonlinear behaviour seen in the simulations but not treated in the analytic work. The stationary modes seen in the analytic results are perhaps observed as transient structures. They may eventually dominate the flow at late times (Woodward et al. 1987).

The role of the kink modes in the stability of slab jets is discussed, and it is argued that the stationary modes are more disruptive than the propagating modes.

Type
Research Article
Copyright
© 1991 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

Artola, M. & Majda, A. J., 1987 Physica D 28, 253 (referred to herein as AM).
Blumen, W., Drazin, P. G. & Billings, D. F., 1975 J. Fluid Mech. 71, 305.
Bridle, A. H. & Perley, R. A., 1984 Ann. Rev. Astron. Astrophys. 22, 319.
Colella, P. & Woodward, P. R., 1984 J. Comput. Phys. 54, 174.
Courant, R. & Friedrichs, K. O., 1948 Supersonic Flow and Shock Waves. Interscience.
Drazin, P. G. & Davey, A., 1977 J. Fluid Mech. 82, 255.
Gerwin, R. A.: 1968 Rev. Mod. Phys. 40, 652.
Godunov, S. K.: 1959 Mat. Sb. 47, 271.
Hjellming, R. M. & Johnston, K. J., 1985 In Radio Stars (ed. R. M. Hjellming & D. M. Gibson), p. 309. Reidel.
Lada, C.: 1985 Ann. Rev. Astron. Astrophys. 23, 267.
Van Leer, B.: 1979 J. Comput. Phys. 32, 101.
Miles, J. W.: 1957 J. Acoust. Soc. Am. 29, 226.
Miles, J. M.: 1958 J. Fluid Mech. 4, 538.
Roy Choudhury, S. & Lovelace, R. V. E. 1984 Astrophys. J. 283, 331.
Winkler, K.-H. A., Chalmers, J. W., Hodson, S. W., Woodward, P. R. & Zabusky, N. J., 1987a Phys. Today 40, 28.
Winkler, K.-H. A., Hodson, S. W., Chalmers, J. W., McGowen, M., Tolmie, D. E., Woodward, P. R. & Zabusky, N. J., 1987b Cray Channels 9, 4.
Woodward, P. R.: 1985 In Numerical Methods for the Euler Equations of Fluid Dynamics (ed. F. Angrand, A. Dervieux, J. A. Desideri & R. Glowinski), p. 493. Philadelpha: SIAM.
Woodward, P. R.: 1986 In Astrophysical Radiation Hydrodynamics (ed. K.-H. A. Winkler & M. L. Norman), p. 245. Reidel.
Woodward, P. R. & Colella, P., 1984 J. Comput. Phys. 54, 115.
Woodward, P. R., Porter, D. H., Ondrechen, M., Pedelty, J., Winkler, K.-H., Chalmers, J. W., Hodson, S. W. & Zabusky, N. J., 1987 Science and Engineering on Cray Supercomputers, p. 557. Minneapolis: Cray Research, Inc.