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Sonic shocks governed by the modified Burgers' equation

Published online by Cambridge University Press:  26 September 2008

S. E. Harris
Affiliation:
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge CB 3 9EW, UK

Abstract

In this paper, we investigate the evolution of N-waves in a medium governed by the modified Burgers' equation. It is shown that the general behaviour when the nonlinearity is of arbitrary odd integer order is the same as for the cubic case. For an N-wave of zero mean displacement, a shock is formed immediately to prevent a multi-valued solution and a second shock is formed at later times. At a finite time, the second shock satisfies a sonic condition and this state persists. The Taylor-type shock structure ceases to be the appropriate description, and instead we have a shock which matches only algebraically to the outer wave on one side. At a larger time still, the other shock is affected but the two shocks remain distinct until the wave dies under linear mechanisms. The behaviour of N-waves of non-zero mean is also examined and it is shown that in some cases, a purely one-signed profile remains.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1996

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References

Cramer, M. S. & Kluwick, A. 1984 On the propagation of waves exhibiting both positive and negative nonlinearity. J. Fluid Mech. 142, 937.Google Scholar
Cramer, M. S., Kluwick, A., Watson, L. T. & Pelz, W. 1986 Dissipative waves in fluids having both positive and negative nonlinearity. J. Fluid Mech. 169, 323336.Google Scholar
Cramer, M. S. & Sen, R. 1992 Evolution equations for mixed nonlinearity. Wave Motion 15, 333355.Google Scholar
Crighton, D. G. 1986 The Taylor internal structure of weak shock waves. J. Fluid Mech. 173, 625642.CrossRefGoogle Scholar
Crighton, D. G. 1992 Nonlinear acoustics. In Modern Methods in Analytical Acoustics (Crighton, D. G., Dowling, A. P., Williams, J. E. Ffowcs, Heckl, M. & Leppington, F. G.), pp. 648670. Springer-Verlag.CrossRefGoogle Scholar
Crighton, D. G. & Scott, J. F. 1979 Asymptotic solutions of model equations in nonlinear acoustics. Phil. Trans. R. Soc. Lond. A 292, 101134.Google Scholar
Gorschkov, K. A., Ostrovsky, L. A. & Pelinovsky, E. N. 1974 Some problems of asymptotic theory of nonlinear waves. Proc. Inst. Elect. Electron. Engrs. 62 (11), 15111517.CrossRefGoogle Scholar
Kluwick, A. 1991 Small-amplitude finite-rate waves in fluids having both positive and negative nonlinearity. In Nonlinear Waves in Real Fluids (Kluwick, A., ed.), pp. 143. Springer-Verlag.Google Scholar
Laforgue, J. G. & O'Malley, R. E. 1993 Supersensitive boundary value problems. In Asymptotic and Numerical Methods for Partial Differential Equations with Critical Parameters, pp. 215223. Kluwer Academic.CrossRefGoogle Scholar
Lange, C. 1983 On spurious solutions of singular perturbation problems. Stud. Appl. Math. 68, 227257.Google Scholar
Larner, R. W. & Trehan, S. K. 1991 Nonlinear waves in a low-density plasma with a strong magnetic field. Astrophys. Space Sci. 180, 93104.Google Scholar
Lee-Bapty, I. P. 1981 Nonlinear wave propagation in stratified and viscoelastic media. PhD Thesis, University of Leeds.Google Scholar
Lee-Bapty, I. P. & Crighton, D. G. 1987 Nonlinear wave motion governed by the modified Burgers' equation. Phil. Trans. R. Soc. Lond. A 323, 173209.Google Scholar
Lighthill, M. J. 1956 Viscosity effects in sound waves of finite amplitude. In Surveys in Mechanics (Batchelor, G. K. & Davies, R. M., Eds), pp. 250351. Cambridge University Press.Google Scholar
Nariboli, G. A. & Lin, W. C. 1973 A new type of Burgers' equation. Z. angew. Math. Mech. 53, 505510.CrossRefGoogle Scholar
Nimmo, J. J. C. & Crighton, D. G. 1982 Bäcklund transformations for nonlinear parabolic equations: the general results. Proc. R. Soc. Lond. A 384, 381401.Google Scholar
Sugimoto, N., Yamane, Y. & Kakutani, T. 1983 Shock wave propagation in a viscoelastic rod. In Proc. IUTAM Symp. Nonlinear Deformation Waves, Tallinn 1982 (Nigul, U. & Engelbrecht, J., eds.), pp. 203208. Springer-Verlag.Google Scholar
Taylor, G.I. 1910 The conditions necessary for discontinuous motion in gases. Proc. R. Soc. Lond. A 84, 371377.Google Scholar
Ward, M. J. 1992 Eliminating indeterminacy in singularly perturbed boundary value problems with translation invariant potentials. Stud. Appl. Math. 87, 95134.Google Scholar
Whitham, G. B. 1974 Linear and Nonlinear Waves. Wiley-Interscience, New York.Google Scholar