床面附近泥沙交换率在悬移质输沙计算中的应用

Application of Mass Exchanges Rates Theory in Suspended Load Transport

总结并分析了关于悬移质运动方程的源/汇项或底部边界条件的已有的处理方法。认为在悬移质输沙计算中,这些方法因引入了平衡输沙概念、忽略了推移质颗粒对悬移质运动的影响或因缺乏床面附近泥沙质量交换率的理论表达式,均存在着某些不足。运用床面附近泥沙质量交换率理沦,对一般的悬移质输沙方程的底部边界条件进行了新的探讨,并提供了关于一维和垂向二维悬移质输沙的计算实例。

This paper analyses and summarizes the previous methods determining the source/sink functions or bed-boundary conditions of transport equation of suspended sediment .There are some limitations in these methods due to introducing the concept of equilibrium transport and ignoring the effects of bed-load on suspended-load transport when considering the mass exchanges near the bed. The theory about mass exchange rates of sediment near the bed previously developed by writers is adopted here to make an inquiry into appropriate boundary conditions on the bed, so that the general equation of suspended sediment transport can be solved. The processes of the adjustment of sand concentrations in one-dimensional or vertical two-dimensional flows have been computed and compared respectively with the measured data, showing reasonably good agreements.