Linear and Nonlinear Wave-Current Interactions over Constant Water Depth

Abstract

Abstract—Nowadays, the exploration of the ocean energy has become necessary and attracted more and more attention by the researchers all over the world due to the pollution and energy depletion issues caused by the consumption of fossil energies. As designing and hydrodynamic analysis of the energy converters in physical experimental tank are both time consuming and expensive, many researchers have developed numerical wave tanks to investigate the problem of wave and current interacting with the energy converters. In this paper, a numerical wave and current tank of the viscous fluid with constant depth is established based on the Reynolds-Averaged Navier-Stokes (RANS) equations with k-ε turbulence closure scheme. The volume of fluid (VOF) method is applied to accurately capture the water free surface. The wave generation, wave absorption and current absorption are accomplished by using the analytic relaxation approach. Based on the numerical wave and current tank established here, the linear wave and nonlinear wave-current interactions are simulated and analyzed. The result shows that the wave generated by using the analytic relaxation approach has the feature of high quality and stability. The numerical results of the linear wave-current interaction are compared with the analytical solution based on the perturbation method, which shows that the numerical wave and current tank established here is accurate and valid. Finally, the influence of current velocity on the wave parameters and the variation of wave crests with wave slopes for linear and nonlinear wavecurrent interactions are also numerically investigated.