【作者】 曲红玲；

【导师】 汪德爟；

【作者基本信息】 河海大学 ， 水力学及河流动力学， 2006， 硕士

【摘要】 河道溃堤后形成的溃堤波传播速度快、破坏性大,对人类生命、财产造成巨大危害,因此,河道溃堤和溃堤波的耦合计算为溃堤造成的圩区淹没过程的预测起着重要的作用。本文建立了一维河道溃堤与二维溃堤波耦合计算的水力模型。其中,河道的计算采用一维明渠非恒定流Saint-Venant方程组,方程采用稳定性好、精度高的Preissmann四点隐式差分格式离散,求解的过程与溃口的数值模拟耦合;溃坝按渐溃计算,将溃口模拟为梯形,随时间线性增大;溃堤波的计算采用在有限体积无结构网格上建立的TVD-MUSCL格式。模拟算例表明,此类格式能够自动俘获间断且能消除激波附近的虚假数值振荡。本文建立的河道溃堤与溃堤波的一、二维耦合计算水力模型实现了真正意义上的一维计算水域向二维计算水域的过渡,模拟了河道溃堤过程、溃口流速变化情况,以及溃堤波传播过程中的传播、绕射、反射及变形等运动特征,模拟比较接近真实溃堤过程。其研究成果能较好的预测圩区淹没过程和淹没范围,为建立河流洪水预警系统提供了可靠的理论基础。更多还原

【Abstract】 The fast-spreading dike-break waves caused by river dike-burst can do great harm to the safe and properties of human being. Therefore, the coupled numerical simulation of river and dike-break waves is of great importance to the prediction of submerging process in polder. A hydraulic model of coupling 1-D river dike-breaking and 2-D dike-break waves is established in the paper. The Saint-Venant equations used in the simulation of river are discretized by the Preissmann implicit scheme, which shows good stability and high precision. The calculation is coupled with the numerical simulation of the breach. The dyke-break process is supposed to be gradual and the breach is simulated as an echelon growing wider with time. The TVD-MUSCL scheme based on FVM (Finite Volume Method) and unstructured grids is used to the computation of dike-break waves. The results show that this scheme is not only nonoscillatory, but also capable of treating hydraulic jump automatically. The hydraulic model of coupling 1-D river and 2-D dike-break waves realizes the transition from 1-D calculation water area to 2-D water area, and it shows the process of river dyke-breaking, the velocity variation of the breach flow and the flow characteristic of diffraction, reflection and deformation during the propagation of dike-break waves. The simulation can realistically show the burst process of dike. It is concluded that the model can predict the submerge process and area effectively, and it provides academic base for establishment of flood forecast system.更多还原