Modelling wave–structure interactions including air compressibility: A case study of breaking wave impacts on a vertical wall along the Saint-Lawrence Bay

Climate change and the associated rise in sea levels impose a challenge for current methods used to predict the processes involved in wave–coastal structure interactions: stochastic nature, coexistence of various phenomena with very different time and length scales, wave transformations ... The main objective of this study is to extend the range of numerical tools available to coastal engineers by presenting a two-phase Favre-Averaged Navier–Stokes model to study wave dynamic interactions with impermeable structures. The model takes into account air compressibility as well as turbulence effects. The model is first validated with two experimental test cases: a sloshing tank with impacts, and wave impacts on a vertical wall with an overhanging slab. After validation, the model is confidently used for the analysis of wave interactions with vertical walls along the Saint-Lawrence Bay, Quebec, Canada. Four incident wave cases representing frequent and extreme storm conditions are selected using the statistical data of a buoy. Results are discussed primarily in terms of the hydrodynamic loads and overtopping on the structure for two breaking and two non-breaking wave cases.