A Two-Phase Flow Model of Wave-Induced Sheet Flow

摘要

This paper presents a two-phase flow model that simulates the fluid andsediment motions in the sheet flow region under oscillatory conditions.Some major forcing terms such as the fluid/particle and particle/particleinteractions and turbulent stresses are included in the model. Byimproving some assumptions of most existing models, the presentmodel specifies the equivalent sand roughness and bed concentration asa function of the Shields parameter, which is variable with time and isphysically more realistic over a mobile flat bed. A wave friction factor,which is governed by a new parameter, is obtained from the presentmodel formulation. The present model is shown to provide a moreaccurate estimate for sediment concentrations than those models usinga constant equivalent sand roughness. Numerical analyses also showthat the suspended sediment retards the mean velocity profile anddecreases turbulent dynamic strength.