水沙运动一、二维分区耦合虚拟点算法

1-D and 2-D zonal coupling algorithm for flow and sediment transport

建立了一种计算具有多空间尺度水沙运动的一、二维分区耦合虚拟点算法。该算法通过在一、二维区域的交界面定义虚拟点,并利用有限元的非结构化网格与单元叠加的特点,将所有一、二维区域连接点的影响系数集成到总体阵中虚拟点的元素上,实现不同分区之间的强耦合作用。同传统的使用简单匹配条件的一、二维分区弱耦合算法相比,该方法可以提高分区耦合计算的稳定性。对算法的正确性用一河口算例进行了检验。

A 1-D and 2-D zonal coupling solution method for flow and sediment transport in estuaries is proposed. By defining fictitious domain at the interface of different computational sub-domains and making use of the characteristics of non-structured meshes and element assembly procedure of the finite element method, a strong zonal coupling algorithm is established which puts all the influence coefficients of the 1-D and 2-D linking nodes into the fictitious nodal elements in the global matrix of the system equations. Compared with conventional zonal coupling algorithms which usually use simple matching conditions, the developed method can greatly improve the calculating stability. Finally, the algorithm is applied to simulate flow and sediment transport in an estuary. The results agree well with the measured data, and large time step can be achieved, which shows that the proposed algorithm is correct and reliable.