沙质河床冲刷过程中床沙级配的模拟  

Simulation of bed load graing in alluvial rivers with sand bed

作　　者：钟德钰[1] 王光谦[1] 丁赟[1] 

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《水科学进展》2007年第2期223-229,共7页Advances in Water Science

基　　金：黄河研究联合基金资助项目(50339020);国家自然科学基金资助项目(50221903)~~

摘　　要：研究了沙质河床冲刷过程中床沙级配的模拟方法。在该方法中采用了新的描述床沙级配变化的动力学方程和床沙级配在交换层内垂向变化与水流强度、河床冲刷强度的关系,反映了冲刷过程中交换层内向床面补充的物理过程。通过室内实验率定了相关参数,建立了床沙级配变化动力学方程的数值求解方法,模拟了床沙冲刷粗化。计算结果与室内实验结果符合较好,表明所建议的方法反映了河床冲刷中床沙级配变化的物理事实,可用于沙质河床冲刷粗化模拟。In this paper an approach to simulate bed load graing due to degradation in alluvial rivers with sand bed is presented. The approach is characterized by introducing a new equation for the evolution of the bed graing in an active layer. The equation permits to describe both the temporal and spatial variances of the bed graing in the active layer. Therefore, in the case of the degradation, the method has ability to simulate the process that the coarsing of the bed material initially occurred at the bed surface which progressively develops into the inner part of the river bed. Being a nonlinear partial differential equation which must be solved with the flow and sediment transport equations, a numerical methodology for the approach is also described in this paper. The simulations of the bed graing during degradation of the channel bed by the approach agree satisfactorily with the available experiments conducted in laboratory flumes. The approach can be useful in the numerical modeling of the fluvial processes.

关 键 词：冲积河流 交换层 沙波 冲刷粗化 床沙级配 

分 类 号：TV142[水利工程—水力学及河流动力学]