Influence of Submerged Breakwater on Longshore Currents

Abstract

Submerged breakwater is a kind of commonly used maritime sheltering structures, so it is necessary to accurately grasp the hydrodynamic characteristics before and after the submerged breakwater. Based on the longshore current experiment in harbor, taking the trapezoid submerged breakwater as the research object, this paper analyzes the influence of submerged breakwater on the mean longshore current by changing the position of submerged breakwater and observes the effect of submerged breakwater on the instability of longshore currents for frequency fluctuation. The results show that the closer the submerged breakwater, cross-shore longshore current velocity has the more obvious tendency to toward the shore. Meanwhile, it will make the upstream direction of longshore current velocity increase and will make the distribution of longshore current velocity in the direction of the whole coast is more uniform. Furthermore, some frequency fluctuation of longshore current instability may strong and new high frequency components of the instability of longshore currents may occur for the increase of the submerged breakwater.