Enhanced Numerical Modeling of Breaking Waves

摘要

Hydrodynamic predictions of waves can be made via numerical solution of the Navier-Stokes equations subject to the appropriate free-surface boundary conditions. For practical flow of naval hydrodynamic interest, simplifications to these equations must be made in order to make the computations feasible. Two approaches for this exist: potential flow, where viscous and rotational effects are formally eliminated from the equations, and Reynolds-averaged approaches, where the equations are time-averaged. Potential flow calculations are significantly faster, but cannot account for viscous effects or turbulence. Reynolds-averaged Navier-Stokes (RANS) calculations require significantly more computational effort, as well as turbulence modeling but constitute a framework which can accommodate both viscous and turbulence effects. The research described herein is motivated by the need for wave breaking models in Reynolds- averaged Navier-Stokes (RANS) calculations. The primary goal of this research effort was the development and application of a numerical capability for the simulation of breaking waves including the effects of fluid viscosity, surface tension and the generation of surface roughness and turbulence. The capability sought was to maximize fidelity to the physics of the free-surface, requiring the numerics to predict all relevant scales.