Numerical analysis on wave load reduction effect of a solid wall with porous plate by macroscopic CFD approach

The porous structures are widely designed in coastal and ocean engineering to reduce the wave load. A macroscopic CFD approach is established to study the wave interaction with a porous plate placed in front of a solid wall. The established numerical wave tank was firstly validated by the analytical results of a vertical wall, and the macroscopic CFD model was validated by the experimental results of a single vertical porous plate. Then the wave load reduction effect of a solid wall with a vertical porous plate in front is investigated, the influences of porosity and relative gap width are compared, and the effects of wave height are also analyzed. The results demonstrate that the porosity and relative gap width are the main effect factors to the wave force reduction effect, and the wave forces on structure increase almost linearly with the increase of relative wave height, while the wave load reduction coefficient and refection coefficient are not linearly. A porosity of 0.2 and relative gap width of 0.2–0.3 are deemed to be optimal geometry parameters at which the wave load reduction effect is optimal. The total horizontal wave force increases nonlinearly with the increase of wave heights, and the quadratic pressure drop condition is essential when studying the wave force on thin porous structures. •A macroscopic CFD model is established to simulate the wave interaction with a porous plate placed in front of a solid wall.•The effects of porosity and relative gap width on wave load reduction coefficient and refection coefficient are analyzed.•The nonlinear effects of wave height and optimal geometry parameters are summarized.