Energy dissipation in shallow water breaking waves*

We present numerical results of energy dissipation in two-dimensional shallow water breaking waves. Using a two-phase DNS approach, we seek a fundamental energy dissipation model and classification scheme for breaking type and mechanism. A solitary wave of amplitude a₀ is initialized over a region of uniform depth h and propagated onto a beach with a uniformly sloping bathymetry of gradient α. We discuss the various types of resulting breakers as a function of these parameters, including plunging, spilling, and surging types. The breaker dissipates kinetic and gravitational potential energy in the wave before it runs up onto the beach. We discuss the energy dissipation and wave run-up in terms of the control parameters and propose a model for energy dissipation adapted from the inertial scaling model for deep water breakers.