A three-dimensional coupled model for time-domain calculation of nonlinear waves

The coupled model,which is the combination of Boussinesq equations and the general description for three-dimensional (3-D) flows with the volume of fluid (VOF) method,has been developed for the numerical simulations of nonlinear waves in a large domain.That is,the whole computational domain Ω is divided into two sub-regions.In the near-field around a structure,Ω₁,the flow is governed by 3-D Navier-Stokes equations and numerically solved by the VOF method.Whereas in the sub-region Ω₂(Ω₂=Ω-Ω₁),the flow is governed by two-dimensional Boussinesq equations and numerically solved with the predictor-corrector algorithm.The velocity and the wave surface elevation are matched to the common boundaries of the two subregions.Numerical verifications have been conducted for the case of wave propagation and interaction with a square caisson.It is shown that the coupledmodel is effective on computing nonlinear waves in a large domain with taking into account the complicated flow field near a structure.