Experimental and Numerical Study of Waves Breaking Over a Submerged Three-Dimensional Bar

Abstract

Depth-induced breaking is the major wave transformation process in coastal waters that significantly influences the wave energy that eventually reaches the coastline. Most studies of depth-induced wave breaking focus on evaluating the wave breaking characteristics on a slope or reef in two dimensions, accounting for the reduction of water depth in the direction of wave propagation. This study investigated wave breaking on a three-dimensional submerged bar through experiments and numerical simulations. Propagation of nonbreaking and breaking waves in different water depths was studied and the energy transferred across the wavefront owing to the presence of a side slope and the nonsimultaneous breaking wavefront was analyzed. The results indicate that classification criteria that account for the local water depth can reasonably predict the type of breaking. The long period waves in the study that did not break over the structure were most affected by refraction. It was also found that the extent of the domain where a steep wave crest is seen increases from nonbreaking to spilling to plunging breaking waves. In the case of the nonbreaking waves, this steep crest propagates along the domain without breaking.