Experimental and numerical investigation of bed morphology in the lee of porous submerged breakwaters

Abstract

In the present work the evolution of a sandy beach in the lee of a permeable submerged breakwater was studied both experimentally and numerically. Three-dimensional laboratory experiments were performed to investigate regular and irregular wave propagation over a porous submerged structure and the resulting bed morphology evolution down-wave of it. The tests included normal wave incidence of breaking and non-breaking, long and shorter waves. The measurements were also used to validate a compound numerical model. The basic solver relies on enhanced Boussinesq-type equations extended to simulate wave propagation over porous beds. The wave module accounts for the entire nearshore zone, from deep water to the swash zone, and it is coupled with a sediment transport module including both bed and suspended loads. Adequate agreement between measurements and model results was achieved in most cases.