Analytical study of oblique wave scattering by a submerged pile–rock breakwater

This study examines the scattering of obliquely incident waves by a submerged pile–rock breakwater, which consists of two rows of closely spaced piles and a rock core between them. Based on linear potential theory, a closed-form analytical solution for the present problem is developed using matched eigenfunction expansions. The analytical solution is novel because of the new submerged pile–rock-type breakwater. The analytical solution is confirmed by an independently developed multi-domain boundary element method solution. The analytical solution is also compared with experimental data for three special cases of the present breakwater. Numerical examples are presented to investigate the effects of structural parameters and wave parameters on the reflection, transmission and energy loss coefficients of the breakwater. It is found that the wave energy dissipation by the submerged pile–rock breakwater is mainly contributed by the rock core, and only a small part of wave energy dissipation is due to the closely spaced piles