| The dike-break long waves cause great damage to polder, and then it is a significant subject for studying the dike-break long wave. It is significant of research for the propagating of the dike-break wave. In the paper, river and the downstream area of dike are regarded as a whole system, and hydraulic model of coupling 1-D river and gradual dike-break is established, therein the Preissmann implicit difference scheme is applied to Main River, and the FVM (Finite Volume Method) is applied to the breach and polder. On the basis of FVM and unstructured grids, TVD ?MUSCL scheme is constructed with high performance. According to the discharge and water level of breach, the scheme is used to compute velocity and water level of center node of all elements. The results show that it is the numerical method of high analyzable degree for the hybrid TVD scheme combinated with FVM, and the scheme is not only sufficiently accurate and nonoscillatory, but also capable of treating automatically hydraulic jump. The hydraulic model of gradual dike-break simulates numerically the 2-D flow of gradual dike-break waves. It shows the variation of flow field on breach, and the complicated flow characteristic of the propagation, diffraction, reflection and deformation of the dike-break waves. The hydraulic model can realistically simulate the burst process of dike, and computational accuracy is satisfied with the engineering demands. It is concluded that the model and methods have scientific decision reference and practical significance for flood warning service, and provide scientific basis for the analysis and prevention of disaster caused by dike destruction. |
PDF Full Text Request