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A regularized model for strongly nonlinear internal solitary waves

Published online by Cambridge University Press:  15 June 2009

WOOYOUNG CHOI*
Affiliation:
Department of Mathematical Science, Center for Applied Mathematics and Statistics, New Jersey Institute of Technology, Newark, NJ 07102, USA
RICARDO BARROS
Affiliation:
Department of Mathematical Science, Center for Applied Mathematics and Statistics, New Jersey Institute of Technology, Newark, NJ 07102, USA
TAE-CHANG JO
Affiliation:
Department of Mathematics, Inha University, Incheon 402-751, Korea
*
Email address for correspondence: [email protected]

Abstract

The strongly nonlinear long-wave model for large amplitude internal waves in a two-layer system is regularized to eliminate shear instability due to the wave-induced velocity jump across the interface. The model is written in terms of the horizontal velocities evaluated at the top and bottom boundaries instead of the depth-averaged velocities, and it is shown through local stability analysis that internal solitary waves are locally stable to perturbations of arbitrary wavelengths if the wave amplitudes are smaller than a critical value. For a wide range of depth and density ratios pertinent to oceanic conditions, the critical wave amplitude is close to the maximum wave amplitude and the regularized model is therefore expected to be applicable to the strongly nonlinear regime. The regularized model is solved numerically using a finite-difference method and its numerical solutions support the results of our linear stability analysis. It is also shown that the solitary wave solution of the regularized model, found numerically using a time-dependent numerical model, is close to the solitary wave solution of the original model, confirming that the two models are asymptotically equivalent.

Type
Papers
Copyright
Copyright © Cambridge University Press 2009

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References

REFERENCES

Bogucki, D. & Garrett, C. 1993 A simple model for the shear-induced decay of an internal solitary wave. J. Phys. Oceanogr. 23, 17671776.2.0.CO;2>CrossRefGoogle Scholar
Bona, J. L., Chen, M. & Saut, J.-C. 2002 Boussinesq equations and other systems for small amplitude long waves in nonlinear dispersive media. I. Derivation and linear theory. J. Nonlinear Sci. 12, 283318.CrossRefGoogle Scholar
Bona, J. L., Chen, M. & Saut, J.-C. 2004 Boussinesq equations and other systems for small amplitude long waves in nonlinear dispersive media. II. Nonlinear theory. Nonlinearity 17, 925952.CrossRefGoogle Scholar
Camassa, R., Choi, W., Michallet, H., Rusas, P. & Sveen, J. K. 2006 On the realm of validity of strongly nonlinear asymptotic approximations for internal waves. J. Fluid Mech. 549, 123.CrossRefGoogle Scholar
Choi, W. 2000 Modelling of strongly nonlinear internal gravity waves. In Proceedings of the Fourth International Conference on Hydrodynamics (ed. Goda, Y., Ikehata, M. & Suzuki, K.), pp. 453–458.Google Scholar
Choi, W. & Camassa, R. 1999 Fully nonlinear internal waves in a two-fluid system. J. Fluid Mech. 396, 136.CrossRefGoogle Scholar
Grue, J., Friis, H. A., Palm, E. & Rusas, P. E. 1997 A method for computing unsteady fully nonlinear interfacial waves. J. Fluid Mech. 351, 223353.CrossRefGoogle Scholar
Grue, J., Jensen, A., Rusas, P. E., & Sveen, J. K. 1999 Properties of large-amplitude internal waves. J. Fluid Mech. 380, 257278.CrossRefGoogle Scholar
Helfrich, K. R. & Melville, W. K. 2006 Long nonlinear internal waves. Annu. Rev. Fluid Mech. 38, 395425.CrossRefGoogle Scholar
Jo, T.-C. & Choi, W. 2002 Dynamics of strongly nonlinear solitary waves in shallow water. Stud. Appl. Math. 109, 205227.CrossRefGoogle Scholar
Jo, T.-C. & Choi, W. 2008 On stabilizing the strongly nonlinear internal wave model. Stud. Appl. Math. 120, 6585.CrossRefGoogle Scholar
Lamb, H. 1945 Hydrodynamics. Dover.Google Scholar
Michallet, H. & Barthélemy, E. 1998 Experimental study of interfacial solitary waves. J. Fluid Mech. 366, 159177.CrossRefGoogle Scholar
Miyata, M. 1988 Long internal waves of large amplitude. In Proceedings of the IUTAM Symposium on Nonlinear Water Waves (ed. Horikawa, H. & Maruo, H.), Berlin: Springer–Verlag, pp. 399406.CrossRefGoogle Scholar
Nguyen, H. Y. & Dias, F. 2008 A boussinesq system for two-way propagation of interfacial waves. Phys. D 237, 23652389.Google Scholar
Nwogu, O. 1993 Alternative form of Boussinesq equations for nearshore wave propagation. J. Waterway, Port, Coastal, Ocean Engng 119, 618638.CrossRefGoogle Scholar
Whitham, G. B. 1974 Linear and Nonlinear Waves. Wiley.Google Scholar