2-D Composite Model for Numerical Simulations of Nonlinear Waves

—A composite model,which is the combination of Boussinesq equations and Volume of Fluid（VOF）method,has been developed for 2-D time-domain computations of nonlinear waves in a large re-gion.The whole computational region Ω is divided into two subregions.In the near-field around a struc-ture,Ω;,the flow is governed by 2-D Reynolds Averaged Navier-Stokes equations with a turbulenceclosure model of k-εequations and numerically solved by the improved VOF method;whereas in thesubregion Ω;（Ω;=Ω-Ω;） the flow is governed by one-D Boussinesq equations and numerically solvedwith the predictor-corrector algorithm.The velocity and the wave surface elevation are matched on thecommon boundary of the two subregions.Numerical tests have been conducted for the case of wave propa-gation and interaction with a wave barrier.It is shown that the composite model can help perform efficientcomputation of nonlinear waves in a large region with the complicated flow fields near structures taken in-to account.