Investigation of non-linear effects resulting from the interaction of tsunami like waves and underwater barriers

The paper presents the investigation results on the nonlinear effects due to the interaction of long gravitational tsunami-like waves with underwater barriers. Mathematical model is based on the two-dimensional Navier–Stokes equations for an incompressible fluid. The numerical results are obtained using the finite volume method and the open source OpenFOAM package.
The new data on the efficiency of thin impermeable underwater barrier are presented. The energy of incident, reflected, and transmitted waves is determined using the integral method. The coefficients of reflection and transmission, as well as the eddy loss coefficient are obtained from the calculation of wave total energy. It is shown that the total efficiency of the thin underwater barrier is governed not only by reflected wave energy, but also by the energy of large-scale eddies generated near the barrier. It is revealed that at the optimum height of the barrier, the energy of reflected wave and the energy absorbed by eddies both depend on the incident wave height. When the nonlinearity parameter of the wave is greater than 0.1, the underwater barrier of optimal height suppresses about 80% of the incident wave energy.