TURBULENT INTERFACIAL BOUNDARY CONDITIONS FOR SPILLING BREAKERS

摘要

This paper presents experimental observations as well as theoretical formulations of the flow structure in the turbulent shear layer in spilling breakers. The theoretical model is developed within the framework of a three-layer system, with the top layer being the two-phase (air/water) turbulent surface layer, and the bottom layer comprising the single phase (water) irrotational flow. The model development in the single phase (water) turbulent shear layer is guided by and validated with PIV flow measurements of a turbulent hydraulic jump. The breaker shear layer is seen to resemble a classical mixing layer with entrainment of fluid into the reverse flow region localized about the mean surface. Preliminary results are reported on interfacial boundary conditions which account for the contributions from the surface layer as well as the evolution of turbulent and mean quantities in the breaker shear layer. Such interfacial boundary conditions can be incorporated into Reynolds-averaged Navier-Stokes numerical models for simulating the spatio-temporal evolution of the turbulent and mean flow in spilling breakers.