AN EVALUATION OF RANS TURBULENCE CLOSURE MODELS FOR SPILLING BREAKERS

Abstract

Breaking waves generate turbulence which, along with the bottom stress, undertow, and other mean currents, is capable of suspending and transporting large quantities of sediment. In the present work, open source computational fluid dynamics software is utilised to evaluate four different turbulence models for the application of spilling breakers in the surf zone. The turbulence models are compared against both existing laboratory data and previous numerical models for surface elevation, velocity and turbulent kinetic energy profiles. The results imply that the different models vary in performance for each of these properties and that for incompressible, multiphase flows, it is important to include density explicitly in the turbulence transport equations. Overall, it was found that, out of the models considered, the best one for spilling breakers is the nonlinear k-epsilon model.