Free surface boundary conditions for spilling waves: theoretical approach and numerical implementation

The recent advancement of numerical modeling has given valuable insights in the knowledge of wave transformation and interaction with coastal structures. In particular, the twophase flow formulation gives advantages towards a more accurate reproduction of the processes and a deeper understanding of the dynamics developing at wave breaking, where an aerated splashing regime is observed. However, such an approach is found to be computationally expensive, especially in the case of large-scale analyses. Aim of the present paper is to describe a novel single-phase numerical model where the adopted free surface boundary conditions take into account the multiphase mixing layer forming at surface deformation. Preliminary comparisons with available data on hydraulic jumps, stationary counterparts of bores, reveal good performances of the model.