Numerical Modeling of Wave Field Around Multiple Submerged Breakwaters

Abstract

This study investigates the variations of spatial velocities and particles trajectories around multiple submerged breakwaters by two-dimensional numerical wave flume established by the boundary element method. The simulations of waves passing over an impermeable submerged dike and a set of double dike are utilized for discussion. The boundaries were discretized by linear elements, and the Lagrangiandescriptions of wave motion are used to describe the variation of flow field around the obstacles cause by wave-obstacle interactions. The trajectories of fluid particles are determined by the instantaneous velocity and the differentiation of time derivatives through forward differencing, and the variations of the trajectories are analyzed and discussed respectively by the path line and velocity field. When the waves propagate over the obstacles, a vortex exists significantly on either side of the upper corner, which rotatescontrarily with the direction of the wave direction. The phenomenon of vortex is more significant when the width and the height of the embankment increased. This was also found in the case of double-column submerged obstacles. Moreover, the existence of vortex was also confirmed in the clip region between the obstacles.