泥沙数学模型近底边界条件Ⅰ:平衡输沙

Bottom boundary condition for suspended sediment transport modeling Ⅰ:Equilibrium state

床面泥沙的上扬是湍流猝发直接作用的结果．本文首先改进作者基于这一基本力学机理所构造的可自由冲刷床面泥沙上扬通量函数，然后利用输沙平衡时泥沙上扬与有效沉降通量相等之条件建立近底含沙量的理论模式．该理论与现有实验数据吻合甚好。

A new function for bed sediment entrainment is first developed based on the averaged turbulent bursting period and its spatial scales.Then,a theoretical model for equilibrium near bed concentration of suspeded sediment is established from the balance between the entrainment and effective sedimentation fluxes.The theory is demonstrated to perform reasonably well compared with existing result of data analysis.The effect of hindered settling is studied,and the result upsets many previous empirical relationships which yield a limiting or unrealistically large near bed sediment concentrations for high flow intensity cases.