Fully nonlinear multi-directional waves by a 3D viscous numerical wave tank
Additional Document Info
A finite-difference scheme and a modified marker-and-cell (MAC) method are used for numerical wave tank (NWT) simulations to investigate the characteristics of nonlinear multi-directional waves. The Navier-Stokes (NS) equation is solved for two fluid layers and the boundary values updated at each time step by a finite-difference time-marching scheme in the frame of rectangular coordinate system. The fully-nonlinear kinematic free-surface condition is satisfied by the density-function technique developed for two fluid layers. The directional resident waves are generated from the inflow boundary by prescribing a snake-like motion along the wavemaker direction. The outgoing waves are numerically dissipated inside an artificial damping zone located at the end of the tank. Using the NS-MAC NWT with both solid and transparent side-wall conditions, the effects of side-wall reflections are studied. The simulation results are compared with the computations by an independently developed potential-based NWT and the experiments conducted in the Offshore Technology Research Center's 3D wave basin.