Investigation of a Multilayer Model for Solitary Wave Breaking Energetics

Breaking waves play a key factor in modeling oceanic and coastal environments. In numerical analyses, detailed energetics of breaking waves are usually only obtainable by computationally expensive methods such as multiphase direct numerical simulation (DNS). Multilayer models present a potential lower-cost alternative at the potential expense of fidelity. In this study, we present an analysis of breaking wave energetics using a vertically-Lagrangian multilayer model within the Basilisk framework (Popinet, 2020, J. Comp. Phys., 418: 109609). We study solitary gravity waves which shoal and break on a simple bathymetry consisting of a uniform initial (“offshore”) depth followed by a uniform beach ramp and finally a uniform depth (“inshore”) beach area. The wave initial amplitude, beach slope, and inshore depth are varied, and the dissipation rate is determined for each case. These resulting dissipation rates are compared to DNS data from prior work. Further, we investigate the applicability of the multilayer model to fully developed turbulent bores which impact vertical walls and compare our results to prior experimental data from the literature, a case which has proved difficult for DNS to model due to the elevated levels of turbulence developed in the bore.