Large-Eddy Simulation of Steep Water Waves

Large-Eddy Simulation is used for the investigation of the breaking of steep water waves on a beach of constant bed slope. The method is built within a multi-fluid flow solver, in which the free surface is tracked using a Volume-of-Fluid method featuring piecewise planar interface reconstructions on a twice-as-fine mesh. The Smagorinsky sub-grid scale model is used for explicit under-resolved turbulence closure, coupled with a new scheme for turbulence decay treatment on the air-side of massively deformable free surfaces. The simulations were conducted for shear Reynolds numbers Re G * ≈Re L * ≈400, based on the mean water depth. The Large-Eddy Simulation formulation in the interface tracking, single-fluid formulation is introduced for this purpose. The approach is demonstrated as a powerful tool for exploring large-scale, interfacial turbulent flows. The discussion focuses on coherent structures formation, the free surface flow effects at breaking, and form drag evolution with the surface.