一维不恒定流泥沙数学模型研究

Modeling of sediment transport in unsteady flow

本文着重对求解一维不恒定流泥沙数学模型控制方程的数值解法进行了研究，结果表明，用线性化方法与非线性迭代计算对圣维南方程进行求解，二者计算结果的差异很小，但线性化方法可以节省大量的计算工作量，且可取较大的时间步长进行计算。对悬移质泥沙运动方程式，相临时层之间用差分法求解，在同一时层上求其分析解，不仅可以避免含沙量计算结果的不合理现象，而且计算量也较小。用丹江口水库下游的资料对模型进行了验证，计算结果与实测资料符合良好。验证计算同时表明，用不恒定流泥沙数学模型进行河床变形计算，计算时间不会比恒定流泥沙数学模型增加很多。

In this paper, numerical method for solving the equation of sediment transport in unsteady flow is studied. The numerical experiment shows that the difference between the linearized and nonlinear iteration calculated results of unsteady flow equation are within 1%, but the computation time of the linearized method is much shorter than the nonlinear iteration calculation, and the time step can be taken longer. An analytical solution is proposed in a given time step for the convection diffusion equation of suspended sediment transport equation. The model is verified by the field data down stream from Dan Jiangkou Reservoir. The calibration simulation shows that the computing time by the unsteady flow model is equivalent to that by the steady flow model.