Vortex suppression of tsunami-like waves by underwater barriers

Abstract

A study of the energy losses of tsunami-like waves due to the formation of large eddies near the underwater barriers has been gaining importance in recent years. However, the conditions of the birth of the large-scale vortex behind the barriers are not yet fully understood. The paper presents the results of theoretical, experimental and numerical studies of the interaction between the long gravitational tsunami-like waves and the impermeable underwater barrier. The proposed mathematical model is based on the approximation of two-dimensional incompressible Navier-Stokes equations. The OpenFOAM toolbox is used to perform the numerical simulation with the method of finite volumes. The air-water interface is identified by the volume of fluid method (VOF). The numerical simulation is tested via a comparison with test activities and experiments carried out in a hydrodynamic wave flume, at the Institute of Applied Mechanics Russian Academy of Sciences. The efficiency of the underwater barrier is assessed as the percentage of the energy loss to the incident wave energy. It is shown that the barrier effectiveness depends on its relative height and the incident wave parameters. New experimental and numerical results are consistent with the theoretical model proposed earlier and research results of other authors.