Modelling of waves and wave-induced currents in the vicinity of submerged structures under regular waves using nonlinear wave-current models

The evolution of waves and wave-induced currents around submerged structures under regular waves is simulated using two nonlinear wave-current models (Boussinesq-type); coupled with a one equation turbulence closure model to simulate the energy dissipation due to wave breaking. The first model is utilized to simulate the evolution of waves and wave-induced currents around porous structures, while the second model is used to simulate those around impermeable structures. The equation of motion for the porous medium in the first model incorporates an empirical Forchheimer-type term for laminar and turbulent frictional losses and inertial term to account for acceleration effects. In both models, an artificial energy dissipation term is introduced to overcome unrealistic flow patterns and surface water fluctuations, which lead to numerical instabilities near steep faces of submerged structures. In the present study, an improved wave breaking sub-model is introduced in 2DH, and the predictive skills of two improved models are investigated with a published and a new set of experimental data. The comparison between simulations and laboratory data show promising results for the wave height, mean-water level and current distribution around submerged structures for 2DH wave propagation.