Numerical simulation of wave-current interaction using a RANS solver

A numerical model is developed to study the wave propagation in the presence of a steady current flow. This model is based on Reynolds-Averaged Navier-Stokes (RANS) equations with k-ε turbulence closure scheme. A novel volume of fluid (VOF) method is applied to accurately capture the water free surface. The current flow is initialized by imposing a steady inlet velocity on one domain end and pressure outlet on the other end, while the desired wave is generated by an internal wave-maker from mass source term of mass conservation equation. Simulated water surface profile and velocity distribution agree well with experimental measurements of Umeyama (2011), indicating that this model has a great ability in simulating wave-current interaction. The validated model is then used to investigate the effects of wave period and current velocity on regular wave-current induced water surface profile and velocity distribution. The propagation of a solitary wave traveling with a following/opposing current is also numerically investigated by this model.