通用河网二维水沙数值模拟

合理的水沙数值模式可为水流运动、河床演变的分析提供依据。基于通用河网二维水流的计算模式,将流域二维河网划分为单一河道、树状河道、环状河道和十字形河道等河网二维基本计算单元,采用二维浅水方程和悬移质输沙基本理论建立节点水位和悬沙控制方程,通过不规则稀疏矩阵的求解获得所有节点上的水位、流速及含沙量,实现全流域的二维水沙耦合计算。通过长江下游澄通河段的验证,在汊道处的计算能很好地体现流场间的相互作用,该模型能满足精度要求。

Generic 2 D River Network Modeling of Flow and Sediment Transports

The reasonable water silt numerical model can provide basis for analysis of flow movement and evolution of river bed. Based on the general 2D river network model, 2D river network is divided into several compute elements including single channel, tree river, ring river and cross river. To implement the coupling of whole basin, this paper adopts 2 D shallow water equation and transport theory of suspended load to establish control equation of water level and sediment on the node of boundary. Then the water level, velocity and sediment concentration on the node are obtained by solving the equation of irregular sparse matrix. Finally, the Chengtong reach of the Yangtze River is selected to verify the performance of the model. The results show that the model can reflect the interactive influence of flow field and meet the accuracy requirement.