一维-二维耦合的防洪保护区洪水演进数学模型
A 1D-2D coupled mathematical model for numerical simulating of flood routine in flood protected zone
-
摘要: 针对防洪保护区溃堤及漫堤洪水演进数值模拟面临复杂计算域、河道-防洪保护区洪水耦合作用等问题,建立了基于侧向联解的一维-二维耦合水动力学模型.通过构造并求解Riemann问题实现一维-二维模型耦合,有效克服了基于堰流公式的传统方法难以处理模型间动量交换的缺点,也避免了堰流公式中流量系数选取的不确定性;提出了时间步长自适应匹配方法,解决了一维模型和二维模型时间步长不一致问题.算例研究表明,该模型可有效模拟河道-防洪保护区耦合系统中漫堤洪水和具有任意溃口形状的溃堤洪水演进过程,具有较好的推广应用价值.Abstract: A 1D-2D coupled hydrodynamic model is developed by using a lateral linkage for numerical simulating of flood routine in flood protected zone with complex geometries and hydraulic interactions between river and flood protected zone. A Riemann problem based model coupling method is proposed to resolve the problem of no momentum exchange and the uncertainty of discharge coefficient from the traditional coupling method based on the weir equation. Besides, an adaptive time-stepping method is used for the 2D model to trace the time line of the 1D model. Numerical results show that the proposed model can effectively simulate the flood due to dyke-overtopping and dyke-break in the coupled system of river and flood protected zone, thus has bright application prospects.