溃坝洪水演进的数值模拟

开发了溃坝洪水演进数值模型,对模型控制方程采用有限体积法进行空间离散,采用具有总变差减小特性的MacCormack预测-校正格式进行时间离散.采用非规则局部不连续网格划分计算区域,增强了模型对复杂地形的适应能力;具有总变差减小特性的数值格式使模型具备了强大的间断波捕捉能力,并消除了模型稳定性对人工黏性的依赖;基于单元属性与基于界面属性的动边界处理技术使模型能合理地模拟非恒定性强、干湿变动剧烈的水陆边界.实际算例表明：模型在强非恒定流状态下具有稳定性及守恒性,可作为溃坝洪水预报及其灾害防范的有力工具.

Numerical simulations of dam-broken flood routing

Numerical model was established to simulate dam-broken flood routing.Finite volume method was adopted to discretize control formulas in space,and TVD(total variation diminishing)MacCormack prediction-correction format was adopted to achieve time discretization.Irregular and partially discontinuous mesh was used to partition the study area,thus the adaptability of the model to complicated terrain was enhanced.TVD feature of the scheme made the model possess strong discontinuity wave capturing ability.Equipped with dynamic boundary treatment technology based on unit attribution and interface attribution,the model could simulate water land interface rationally,which was very unsteady and involves strong dry-wet alteration.The model performs good stability and conservation in the simulation of prototype flood routing under the strong unsteady condition,which can be used as an effective tool for dam break flood forecast and disaster precaution.