Wave propagation over a submerged porous breakwater with steep slopes

Abstract

The applicability of a Boussinesq-type wave model in simulating wave propagation over submerged breakwaters is studied. The original model is able to reproduce wave propagation including wave breaking in practically any water depth over impermeable mild sloping bottom. Extension of that model is presented to cover steep slopes, permeable structures and breaking conditions typically out of the applicability range of the main solver. This extension is attained by coupling the main solver with a nonlinear Darcy–Forchheimer equation and with a modified wave breaking module. Experiments in a wave flume were conducted to measure free surface elevation for regular waves propagating over such structures. The modified model is able to accurately capture the nonlinear phenomena due to wave propagation over submerged structures of any porosity. Also, the wave breaking prediction technique, introducing breaker type categorization in terms of the dominant form, shows that the modified model is able to adequately simulate breaking effects, including spilling, plunging and collapsing breakers, for long and short waves. The numerical simulations when compared with measurements show very good agreement in most cases.