【摘要】 建立反映天然条件下大坝瞬时溃决水流特点的数学模型,模型采用有限体积法对二维浅水方程进行非结构离散,利用Roe格式的近似Riemann解来计算网格界面处的通量。为避免采用堰流公式估算溃口流量带来的误差,将水库库区与大坝下游的计算区域统一划分计算网格,溃口处流量由计算格式自动识别。以Malpasset水库为例,对数学模型进行了验证。通过与实测数据的比较可以看出,该模型较好地模拟了大坝瞬时溃决后的洪水运动过程,模拟结果可以为溃坝洪水风险分析提供科学依据。更多还原

【Abstract】 A numerical model that reflects the characteristics of instant dam failure flow under natural conditions was developed.In this model,the two-dimensional shallow water equation is spatially discretized using the finite-volume method.Roe’s approximate Riemann solver is used to compute the flux on the grid interface.In order to avoid errors in the calculation of dam break flux with the weir formula,the reservoir area and the downstream region are meshed together and the dam break flux is computed automatically with the computing scheme.The model is validated through the case study of the Malpasset Reservoir.The model simulated the flow during instant dam failure accurately,according to comparison between the calculated value and measured data.This model can provide a scientific foundation for dam break flood risk analysis.更多还原