清水冲刷河床粗化数学模型

本文建立了大坝下游清水冲刷河床粗化一维数学模型。该模型考虑了非均匀推移质不平衡输移,并引入混合层模式用于模拟河床组成的变化。利用Preissmann隐式格式求解水流方程组,用显式格式求解河床变形方程及床沙级配调整方程。该模型侧重于模拟河床粗化过程,也能用于河床一维变形计算。利用我们做过的清水冲刷水槽实验资料对模型进行了全面的验证,取得了令人满意的结果。

Mathematical Modelling of Riverbed Armoring by Clear Water

A one-dimensional mathematical model of riverbed armoring by clear water has been developed in this paper. This model takes into account non-equilibrium transport of non-uniform bedload and introduces the mixed layer model to calculate the changes of bed material grain class. The equations of liquid(water continuity, flow momentum)and solid(riverbed deformation, bed sediment composition) are uncoupled by using the Preissmann scheme and explicit scheme respectively. The model mainly simulates the process of riverbed armoring. It can calculate riverbed deformation also. The results of the transport rate and the grain size distribution of the bedload at the end of the downstream in the process of time, and the grain size distribution of the bed material in the process of time and distance arc all in close agreement with measuiments.