Applications of Wave Generation inside Solution Domain of Simulations Based on Navier-Stokes Equations

摘要

When simulating free surface flows with the Navier-Stokes equations the standard procedure to create free surface waves is to prescribe the corresponding values for velocities and pressures at the inlet boundaries [2]. Alternatively, waves can be generated as in experiments, e.g. by imposing a flap-like movement on one or more boundaries of the solution domain. However, such wave generation mechanisms produce reflections when the wave generating boundary is hit by waves coming towards it. To avoid reflections from the solution domain boundaries the most common and effective approach is a combination of coarsening the grid towards the corresponding boundary and applying a damping zone in the vicinity of the boundary, where - similar to a porous medium - the vertical fluid velocity component is damped by adding a source term into the corresponding equations for momentum conservation [1]. This approach is not applicable to wave creating boundaries since the created waves would experience damping as well.