The numerical simulation of local scour in front of a vertical-wall breakwater*

A two-dimensional numerical wave flume was established based on an arbitrary Lagrangian-Eulerian (ALE) description of the Navier-Stokes equations for incompressible and viscous fluid, which is spatially discretized by finite element method (FEM) and marching in time with a fractional step algorithm. The second-order nonlinear Stokes waves were generated numerically and the standing waves were formed in front of a vertical-wall breakwater. The transports of uniformly noncoherent sediment bed load were modeled to simulate the local scour process at the toe of the breakwater. The scouring patterns at the earlier stage of scouring agree with that obtained in Xie's experiment (1983).