Numerical analysis of wave-induced current within the inhomogeneous coral reef using a refined SPH model

The effects of reef permeability on the spatial distributions of wave-induced current inside and outside the inhomogeneous coral reef body are investigated using an improved weakly compressible smoothed particle hydrodynamic (WCSPH) mixture model. The governing equations are formulated based on the two-phase mixture theory without considering the solid phase motion in terms of the intrinsic velocity and fluid density. The developed WCSPH mixture model is firstly validated by comparing the predicted results with the corresponding available data for Darcy seepage flow in a U-tube with permeable soil, wave damping over a permeable seabed and wave transformation over a permeable reef. The validated model is then applied to study the spatial distributions of wave-induced current inside and outside the permeable reef body with different porosity and porous layer thickness. Finally, a parametric study is carried out to investigate the effects of different porosity distribution types on wave-induced currents.