基于湍流猝发的床面泥沙上扬通量

Turbulent bursting-based sediment pick-up flux from loose bed

根据湍流猝发平均周期及其空间尺度，构造了可自由冲刷床面泥沙上扬通量的理论模式．该模式较现有各种经验模式能更准确地描述上扬通量随水沙条件的变化规律．由此可为泥沙数学模型建立具有较好力学基础的近底含沙量边界条件．

Sediment pick-up is closely associated with the bursting process in wall turbulent flows.Based on this mechanism,a new theoretical model for sediment pickup from loose bed is developed using the average bursting period scaled on inner variables and the spatial scales of bursts.The pick-up flux depends strongly on the frictional velocity. The present model is demonstrated to produce results in excellent agreement with existing laboratory data in the literature.More well-grounded bottom boundary conditions for sediment transport models are anticipated.