A multi-domain BEM approach for hydrodynamic analysis of arbitrarily shaped 2D floating breakwaters with wide porous media

Abstract

A numerical formulation for evaluating the hydrodynamic behaviours of arbitrarily shaped two-dimensional (2D) floating breakwaters with wide porous media is developed based on the multi-domain boundary element method (BEM). Both diffraction and radiation problems are tackled and key hydrodynamic quantities such as wave exciting forces, added masses, radiation damping, and response amplitude operators (RAOs) are obtained. In addition, three representative performance indices for floating breakwaters—transmission, reflection, and dissipation coefficients—as well as mooring loads are computed. The present numerical formulation is verified by comparing the results with those from an analytical approach in the previous literature. Furthermore, previously published solutions for floating compound breakwaters with wide porous media are compared with experimental data for validation purposes. Through parametric studies, the effect of the location and shape of wide porous media attached to floating breakwaters are investigated. For the first investigation, the porous media are attached to the sides, top, bottom, top-and-bottom, and sides-and-bottom of rectangular floating breakwaters. Next, the shapes considered include semi-circular, rectangular, upright trapezoidal, and inverted trapezoidal geometries. The present numerical formulation will serve as a useful tool for evaluating the hydrodynamic behaviours of arbitrarily shaped 2D floating breakwaters with wide porous media.