中文摘要：

基于N-S方程、RNG k-ε模型和有限差分法建立了溃坝洪水分析的三维数学模型,进行了溃坝洪水通过直角弯道的模型试验,并将计算值与实体模型试验结果中洪水的实测值进行对比,结果表明渠道内洪水位的计算值与实测值高度吻合,流速大小与方向也基本一致。为进一步研究溃坝洪水冲刷问题,在水流模型的基础上加入了泥沙模型,并采用槽宽突变渠道中溃坝洪水冲刷的模型试验进行验证,验证结果表明洪水水位的实测值与数值模拟计算值吻合较好,冲刷完成后的冲刷坑深与堆丘高度也基本一致,说明所建的泥沙模型在研究溃坝洪水泥沙冲刷问题时有较好的准确性与实用性。

英文摘要：

Based on N-S equation and RNG k-ε model and finite difference method, a three-dimensional numerical model used for studying dam-break flood was established in this paper and the model was validated with the model test of dam-break flow propagation in channel with 90° bend. The calculation results show that the water surface profile and velocity distribution are in good agreement with the value of hydraulic model tests. In order to further study the problem of dam-break scour, a sediment scour model was established based on the three-dimensional numerical model, then the scour model was validated with the model test of dam-break flow on mobile bed in abruptly widening channel.The results show that the water profile, scour hole depth and peak of dune are all fit well in physical test and numerical simulation, which prove that the sediment scour model is greatly possible and practical in the dam-break scour research.