Breaking of internal solitary waves in a three-layer fluid over an obstacle

A three-layer shallow water model in the Boussinesq approximation with allowance for nonlinearity, dispersion, and mixing is used to describe the propagation and breaking of large-amplitude internal waves interacting with uneven bottom topography. The proposed equations of motion are solved numerically by applying the Godunov method with additional inversion of an elliptic operator at each time step. Stationary solutions in the form of mode-1 solitary waves are constructed. Mixing processes induced by breaking internal solitary waves due to their interaction with a single or combined obstacle are modeled. It is shown that the numerical results are in good agreement with experimental data and direct numerical simulation.