Interaction of nonlinear progressive viscous waves with a submerged obstacle

The present work is to establish a numerical model to investigate the interaction of a two-dimensional periodic progressive wave train over a submerged rectangular obstacle. We consider progressive wave motions in viscous fluids and solve the continuity and the Reynolds averaged Navier-Stokes equations directly. The two-equation k−ε turbulence model is employed to simulate the turbulent transport quantities and solve the free surface flow problem. Numerical results for the wave interaction with a submerged obstacle are obtained and compared with the existing experimental results. Good agreements are found in the water elevation and vortex patterns between numerical and experimental results. In addition, we look into the mechanism and the behavior of the nonlinear waves while interacting with the rectangular obstacle at high Reynolds number. We use the ratio of wave height to water depth to characterize the nonlinearity of incoming waves. Numerical results reveal that the vortices formed by an incoming wave train are highly dependent on the ratio of wave height to water depth. Results also show that highly nonlinear waves induce strong vortices around a submerged obstacle. The interacting effect of obstacle length on the flow is also discussed in the study. It has been observed that the vortex motion around the obstacle is enhanced as the length of the submerged obstacle decreases.