×

On stabilizing the strongly nonlinear internal wave model. (English) Zbl 1386.76048

Summary: A strongly nonlinear asymptotic model describing the evolution of large amplitude internal waves in a two-layer system is studied numerically. While the steady model has been demonstrated to capture correctly the characteristics of large amplitude internal solitary waves, a local stability analysis shows that the time-dependent inviscid model suffers from the Kelvin-Helmholtz instability due to a tangential velocity discontinuity across the interface accompanied by the interfacial deformation. An attempt to represent the viscous effect that is missing in the model is made with eddy viscosity, but this simple ad hoc model is shown to fail to suppress unstable short waves. Alternatively, when a smooth low-pass Fourier filter is applied, it is found that a large amplitude internal solitary wave propagates stably without change of form, and mass and energy are conserved well. The head-on collision of two counter-propagating solitary waves is studied using the filtered strongly nonlinear model and its numerical solution is compared with the weakly nonlinear asymptotic solution.

MSC:

76B55 Internal waves for incompressible inviscid fluids
76E20 Stability and instability of geophysical and astrophysical flows
86A05 Hydrology, hydrography, oceanography
Full Text: DOI

References:

[1] Ramp, Internal solitons in the Northeastern South China Sea. Part I: Sources and deep water propagation, IEEE J. Ocean Eng. 29 pp 1157– (2004)
[2] Benjamin, Internal waves of finite amplitude and permanent form, J. Fluid Mech. 25 pp 241– (1966) · Zbl 0145.23602
[3] Benney, Long nonlinear waves in fluid flows, J. Math. Phys. 45 pp 52– (1966) · Zbl 0151.42501 · doi:10.1002/sapm196645152
[4] Ostrovsky, Internal solitons in laboratory experiments: Comparison with theoretical models, Chaos 15 pp 037111– (2005) · Zbl 1144.37394
[5] Helfrich, Long nonlinear internal waves, Ann. Rev. Fluid Mech. 38 pp 395– (2006)
[6] Choi, Long internal waves of finite amplitude, Phys. Rev. Lett. 77 pp 1759– (1996)
[7] Choi, Fully nonlinear internal waves in a two-fluid system, J. Fluid Mech. 396 pp 1– (1999) · Zbl 0973.76019
[8] M. Miyata Long internal waves of large amplitude Proc. IUTAM Symp. on Nonlinear Water Waves H. Horikawa H. Maruo Eds. 399 406 Springer Verlag 1988
[9] Ostrovsky, Evolution equations for strongly nonlinear internal waves, Phys. Fluids 15 pp 2934– (2003) · Zbl 1186.76407
[10] Camassa, On the realm of validity of strongly nonlinear asymptotic approximations for internal waves, J. Fluid Mech. 549 pp 1– (2006)
[11] Jo, Dynamics of strongly nonlinear solitary waves in shallow water, Stud. Appl. Math. 109 pp 205– (2002) · Zbl 1152.76342
[12] Grue, A method for computing unsteady fully nonlinear interfacial waves, J. Fluid Mech. 351 pp 223– (1997) · Zbl 0903.76069
[13] Liska, Nonhydrostatic two-layer models of incompressible flow, Computers Math. Applic. 29 pp 25– (1995) · Zbl 0819.76095
[14] Krasny, Desingularization of periodic vortex sheet roll-up, J. Comp. Phys. 65 pp 292– (1986) · Zbl 0591.76059
[15] Grue, Properties of large amplitude internal waves, J. Fluid Mech. 380 pp 257– (1999) · Zbl 0938.76512
[16] Miyata, An internal solitary wave of large amplitude, La mer 23 pp 43– (1985)
[17] M. Longuet-Higgins E. Cokelet The deformation of steep surface waves in water; I. A numerical method of computation Proc. R. Soc. Lond. A 350 1 26 1976 · Zbl 0346.76006
[18] Li, A numerical study of the exact evolution equations for surface waves in water of finite depth, Stud. Appli. Math. 113 pp 303– (2004) · Zbl 1141.76352 · doi:10.1111/j.0022-2526.2004.01534.x
[19] Drazin, Hydrodynamic Stability (1981)
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.