Investigation of Wind Effects on Wave Overtopping at Sea Defences

Quantitative assessments of wind effects on wave overtopping are carried out using CFD simulations with the open source solver OpenFOAM. The desired wind speeds are achieved efficiently by introducing artificial pressure gradient terms for desired zones inside the computational domain. A new run-time post processing utility has been developed to track the overtopping water over a sea defence. Numerical results are validated using (1) a past experimental study with simple sloped defence and (2) new experiments that were conducted at HR Wallingford with a more realistic structure. Several additional calculations with both small and large water depths reveal that with a high wind speed the overtopping volume can be increased by 30% compared to that without wind. The 2D code is then extended to wave overtopping at a semi-circular beach in the plane as a hypothetical 3D sea defence in order to investigate the 3D effect of wind speeds.