Generating Water Waves on Steady Currents Using Mass Source Wave Maker Coupled with Analytical Relaxation Wave Absorber

In order to numerically simulate the wave-current interaction problems frequently encountered by aquaculture structures, a two-dimensional numerical wave-current tank model was established here based on a mass source wave maker coupled with an analytical relaxation wave absorber. The wave-maker model and the wave-absorber model were embedded into a two-dimensional RANS solver, which was closed with RSM turbulence scheme. The volume of fluid (VOF) method was adapted to accurately capture the free surface between water and air. To generate a steady uniform current flow, the uniform current flow velocity was calculated at the left-hand-side (LHS) and right-had-side (RHS) outflow boundaries, respectively. Once the steady uniform current flow was generated over the whole computational domain, the target water wave was marked within a specified region by embedding the mass source function based on wave theory into the mass conservation equation and then propagated on the generated uniform current flow. To verify the accuracy of the numerical wave-current tank established here, some of the obtained numerical results were then compared with the experimental results and the analytical solutions, and they agreed well with each other, indicating that the model developed here has great ability in simulating water waves on uniform currents over constant water depth. The established numerical wave-current tank was then used to study the optimal layout of the mass source region and the effects of water current velocity on water surface wave parameters during regular wave coupling with uniform water currents. Meanwhile, the established model was extended to generate steep wave and apply in deep water conditions. Finally, the proposed methods were applied to investigate the wave-current-structure interaction problems and the propagation of solitary waves traveling with coplanar/counter currents. Model-data comparisons show that the developed model here is potentially useful and efficient for investigating the inevitable wave-current-structure interaction problems in aquaculture technologies.