恢复饱和系数初步研究

A study on coefficient of saturation recovery

悬移质不平衡输沙研究中，往往有一重要参数即恢复饱和系数难以确定。本文首先根据作者由泥沙运动统计理论建立的扩散方程在底部的边界条件、导出了恢复饱和系数的定义及方程。其次在某种假定下，给出有关参数及恢复饱和系数的表达式，并做了一些数值计算。结果表明，在一般水力因素条件下。平衡时恢复饱和系数在０．０２～１．７８之间，平均接近０．５。这与我们以前采用的经验结果淤积时为０．２５，冲刷时为１是一致的。最后还引进了不同冲淤状态，恢复饱和系数与平衡时的差别，以及其变化关系。

Usually it is difficult to determine the coefficient of saturation recovery for nonequilibrium transportation of suspended load. In this paper, the definition and equation of the coefficient of saturation recovery are introduced based on the bottom condition of diffusion equation, which is derived by the authors from the stochastic theory of sediment motion. An expression of the coefficient of saturation recovery and the relevant parameters are then obtained based on certain presumptions. The value of the coefficient is calculated as well. Under equilibrium condition, the value of coefficient is between 0.02 and 1.78 with the average value about 0.5. It shows that the results which are very near to empirical values 0.25 for deposition and 1.0 for erosion as adopted before are reasonable. Finally, the differences of coefficient of saturation recovery among the equilibrium, erosion and deposition conditions are discussed, and a general expression available for various conditions is suggested.