Numerical investigation of breaking waves impact on vertical breakwater with impermeable and porous foundation

Abstract

Three different types of breaking waves impact on a vertical breakwater with impermeable and porous foundations are studied using our in-house solver, DUTFOAM. The numerical model is based on the Volume-Averaged Reynolds-Averaged Navier-Stokes (VARANS) method and the numerical results are compared with experimental data to obtain a reasonable agreement. The characteristics of flow fields inside and outside the porous region under different breaking wave conditions are discussed and compared. When considering the impermeable foundation, breaking waves that entrapped small air pockets pose the most extensive pressure and forces, while the broken waves exerted the minimum. The porous foundation, with varying porosity values, dramatically affects the flow field and resulting structural forces. Our findings demonstrate that more considerable peak pressures and higher acting positions with porous foundations than impermeable situations for all three breaking wave conditions. Moreover, a sharp increase in horizontal forces and overturning moments occurs in broken wave conditions when the porosity equals 0.5, which poses a threat to stability and deserves additional attention.