Numerical investigation of the interaction between an inverse T-type fixed/floating breakwater and regular/irregular waves

- The zonal hybrid RANS/laminar method captures the 3DOF motion of the floating breakwater with less wave energy loss.
- The wave transmission is negatively correlated with the pitch motion.
- The wave energy redistribution is enhanced by the wave radiation due to the moving floating breakwater.

This paper presents a numerical analysis of nonlinear interaction between inverse T-type free surface breakwater and regular/irregular waves using a zonal hybrid RANS/laminar method based on an improved mesh updating strategy, which divides the whole computation domain into several parts to avoid low quality mesh elements caused by the large-scale movement. Each mesh zone is specified with different degrees of motion freedom. In the stationary zone where the flow is less influenced by the body motion, the flow is assumed to be laminar to avoid energy loss during the wave propagation. The RANS turbulence model applies only to the moving zones that move with specified motion components (sway/heave/pitch). The zonal hybrid RANS/laminar method is validated by comparison with the experimental data measured under a regular wave with period Tw=1.0s and amplitude A=0.0192m. The simulated motion responses, especially the sway motion amplitudes, of the floating breakwater are agree well with the experimental measurements. The motion responses and the energy-dissipating performances of the fixed/floating inverse T-type-type breakwater under regular/irregular waves are further investigated.