Modelling wide perforated breakwater with horizontal slits using Hybrid-BEM method

Abstract

A hybrid boundary element method has been developed to efficiently solve the hydrodynamic response of a wide perforated breakwater with arbitrary hull geometry and multiple horizontal slits. The fluid subdomains inside the slits were considered as rectangular and analytical eigenfunctions of the slit area were applied to derive the boundary condition at the interface. The involvement of analytical solutions in the numerical boundary element method (BEM) is the novelty of the present approach. The 2D numerical solution was verified with analytical solution of perforated rectangular breakwater to show the validity of the proposed hybrid BEM. Parametric studies have been performed to study the effect of porosity, position and layout of the slits. It has been found that the slits generally reduce the diffracted and radiation potentials, and would be most effective when placed near the free surface. The approach was also extended to 3D channel flow and the results were calibrated against an experimental study performed in the wave flume.