Head-on Collision of Internal Waves of Large Amplitudes

V. S. Maderich, K. V. Terletska, I. A. Brovchenko

The dynamics and energetics of a frontal collision of internal solitary waves of high amplitude propagating in a two-layer stratified fluid are studied numerically. The computations are carried out within the framework of the Navier—Stokes equations in the Boussinesq approximation. It was shown that the frontal collision of internal solitary waves of moderate amplitude leads to a small phase shift and to the generation of dispersive wavetrain trailing behind transmitted solitary wave. The phase shift grows with increasing amplitudes of the interacting waves and approaches the limiting value at large amplitudes of the waves. The deviation of the maximum wave height during collision from the twice the amplitude does not grow with increasing amplitude in the case of interaction of wave of large amplitude in contrast to the moderate amplitude waves. It was shown that the interaction of waves of large amplitude leads to the shear instability and the formation of Kelvin—Helmholtz vortices in the interface layer, however, subsequently waves again become stable.

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