Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-19T00:31:33.639Z Has data issue: false hasContentIssue false

Overturning of nonlinear acoustic waves. Part 1 A general method

Published online by Cambridge University Press:  26 April 2006

P. W. Hammerton
Affiliation:
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge CB3 9EW, UK
D. G. Crighton
Affiliation:
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge CB3 9EW, UK

Abstract

We consider model nonlinear wave equations of the form ut + uux = [Hscr ](x,t;u, ux,…) arising in gasdynamics and other fields, [Hscr ] incorporating various linear mechanisms of dissipation and dispersion. If [Hscr ] includes a thermoviscous dissipation term ∈uxx, then it is generally believed that u(x,t) will remain single-valued for all t > 0 and all single-valued u(x, 0), for any ∈ > 0. The question addressed here is whether, if thermoviscous dissipation is excluded from [Hscr ], u(x, t) remains single-valued for all t > 0, or whether certain dissipative-dispersive mechanisms (such as relaxation processes) are in themselves insufficient to prevent wave overturning. To answer this we propose a numerical scheme based on the use of intrinsic coordinates ψ = ψ(s, t) to describe the waveform at each time. In this paper, the method is described and validated by comparisons with the exact solutions for certain [Hscr ] ([Hscr ] = 0, [Hscr ] = -αu, [Hscr ] = ∈uxx). These comparisons show that the scheme is free of numerical viscosity effects which preclude the solution of the problem by finite-difference or spectral methods applied to the signal u(x, t), that it can reliably distinguish between finite-time overturning and merely the formation of steep gradients, and that it can accurately predict the time of overturning when it does occur. Having established the validity of the method, attention can then be turned to those cases where criteria for overturning have not as yet been determined by conventional methods. In Part 2, harmonic wave propagation through a relaxing gas is investigated.

Type
Research Article
Copyright
© 1993 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

Abramowitz, M. & Stegun, I. 1965 Handbook of Mathematical Functions. Dover.
Blythe, P. A. 1969 Nonlinear wave propagation in a relaxing gas. J. Fluid Mech. 37, 3150.Google Scholar
Chester, W. 1964 Resonant oscillations in closed tubes. J. Fluid Mech. 18, 4464.Google Scholar
Crighton, D. G. 1979 Model equations of nonlinear acoustics. Ann. Rev. Fluid Mech. 11, 1133.Google Scholar
Crighton, D. G. & Scott, J. F. 1979 Asymptotic solutions of model equations in nonlinear acoustics. Phil. Trans. R. Soc. Lond. A 292, 107134.Google Scholar
Hammerton, P. W. & Crighton, D. G. 1993 Overturning of nonlinear acoustic waves. Part 2. Relaxing gas dynamics. J. Fluid Mech. 252, 601615.Google Scholar
Lighthill, M. J. 1956 Viscosity effects in sound waves of finite amplitude. In Surveys in Mechanics (ed. G. K. Batchelor & R. M. Davies), pp. 250351. Cambridge University Press.
Longuet-Higgins, M. S. & Cokelet, E. D. 1976 The deformation of steep surface waves on water: I. A numerical method of computation. Proc. R. Soc. Lond. A 350, 126.Google Scholar
Meyer, R. E. 1986 a On the shore singularity of water waves. I. The local model. Phys. Fluids 29, 31523163.Google Scholar
Meyer, R. E. 1986 b On the shore singularity of water waves. II. Small waves do not break on gentle beaches. Phys. Fluids 29, 31643171.Google Scholar
Meyer, R. E. 1986c Regularity for a singular conservation law. Adv. Appl. Maths 7, 465501.Google Scholar
Naumkin, P. I. & Shishmarev, I. A. 1982 On the breaking of waves for the Whitham equation. Soviet Math. Dokl. 26, 150152.Google Scholar
Naumkin, P. I. & Shishmarev, I. A. 1983 On the Cauchy problem for Whitham's equation. Soviet Math. Dokl. 28, 719721.Google Scholar
Ockendon, H. & Spence, D. A. 1969 Nonlinear wave propagation in a relaxing gas. J. Fluid Mech. 39, 329345.Google Scholar
Polyakova, A. L., Soluyan, S. I. & Khokhlov, R. V. 1962 Propagation of finite disturbances in a relaxing medium. Soviet Phys. Acoust. 8, 7882.Google Scholar
Sugimoto, N. 1989 Generalized Burgers equations and fractional calculus. In Nonlinear Wave Motion (ed. A. Jeffrey), pp. 162199. London: Longman.
Sugimoto, N. 1990 Evolution of nonlinear acoustic waves in a gas-filled pipe. In Frontiers of Nonlinear Acoustics - Proc. 12th ISNA (ed. M. F. Hamilton & D. T. Blackstock), pp. 345350. Elsevier.
Sugimoto, N. 1991 Burgers equation with a fractional derivative; hereditary effects on nonlinear acoustic waves. J. Fluid Mech. 225, 631653.Google Scholar
Varley, E. & Rogers, T. G. 1967 The propagation of high-frequency finite acceleration pulses and shocks in visco-elastic materials. Proc. R. Soc. Lond. A 296, 498518.Google Scholar
Whitham, G. B. 1967 Variational methods and applications to water waves. Proc. R. Soc. Lond. A 299, 625.Google Scholar