Wave breaking simulation by non-hydrostatic numerical model

Wave breaking is one of the key hydrodynamic issues in coastal engineering, and the research on numerical simulations of wave breaking is in the ascendant. Based on the static pressure model, a completely non-hydrostatic model is proposed by introducing the dynamic pressure term and has been successfully applied to the simulation of dispersive water waves. Vertical coordinate transformation approach is adopted to capture the free water surface, which exhibits improved computationally efficiency as compared to the conventional VOF method. However, the vertical coordinate transformation approach cannot simulate large-curvature free surface deformation, i. e., the wave breaking process. Therefore, a model-splitting method is developed to simulate breaking waves, in which the model in the wave breaking zone is divided into a hydrostatic model and a non-hydrostatic model. That is, near the peaks of breaking waves the model is degraded to the hydrostatic model, which persists until the end of wave breaking and thereafter reverts to the dynamic pressure model. In this paper, the applicability of the model-splitting method and its accuracy for the simulation of wave breaking process are validated against canonical cases. Since this method has not introduced any new generalized model for wave breaking process, it has high computational efficiency and can be applied to the simulation of large-scale wave deformation, fragmentation and propagation in the coastal zone.