基于非结构网格的溃坝水流干湿变化过程数值模拟

Numerical modeling of dam-break water flow with wetting and drying change based on unstructured grids

本文采用非结构网格的有限体积法对具有复杂地形的溃坝水流进行了数值模拟。利用Roe格式的近似Riemann解来计算界面通量,对底坡源项进行特征分解和迎风处理以保证格式的和谐性,对摩阻项采用了半隐式离散的方法来增加计算的稳定性,采用了一种稳定有效的动边界处理方法来模拟干湿边界的变化。最后通过两个算例对本文的模型进行了验证,结果表明该模型具有较好的稳定性和可靠性,能够较好的模拟具有复杂地形的溃坝水流演进过程。

An unstructured finite-volume model is presented for simulating dam-break water flows over complex topographies. The model uses the Roe＇ s approximate Riemann solution in the calculation of flow flux, the characteristic decomposition method is used for upwind scheme in dealing with the bed slope source term, and the semi-implicit approach is used for the friction source terms. A robust procedure is adapted to efficiently and accurately simulate the movement of a wet/dry boundary. The established model shows good stability and accuracy as it is tested with two sets of measured data, hence it can be used to simulate dam-break water flows over complex topographies.