A turbulence model of wave-induced sheet flow

Abstract

This paper present a turbulence model that describes the sediment concentration and turbulent boundary layer of a wave-induced sheet flow. The simultaneous interactions between oscillatory, turbulent flow, and suspended sediment are included. The model specifies the equivalent roughness as a function of the Shields parameter, which is variable with time and is more physically realistic over a mobile flat bed. A wave friction factor, which differs from the conventional rough wall law, is obtained from the velocity gradient. A comparison of the turbulent boundary layer and sediment concentration for different equivalent roughness is given. The present model is shown to provide more accurate estimates than those using an equivalent roughness. Numerical results also show that the presence of suspended sediment retards mean velocity profile and decrease corresponding turbulence dynamic quantities.