Abstract: A numerical method for simulating the transient open-channel flow by coupling 1D shallow water wave and 3D VOF models was proposed. Firstly，by establishing the mathematical relationship between the variables of the two calculation models，the proposed method realized that 3D region provided flow for 1D region and 1D region provided the pressure and volume fraction distribution of water for 3D region. Then，two typical transient conditions of rectangular cross-section channel during load rejection and increase were simulated by coupling method. Comparing the above results with the calculation results obtained by 1D shallow water wave model， it shows that the proposed method is qualitatively correct，and the accuracy is high in quantitative. Finally，the transient open- channel flow in a pressure fore bay of a hydropower station with inlet pipes was simulated by the proposed method，and the critical parameters，such as the maximal overflow discharge，the maximal and minimal water levels were obtained. The coupling method combines the efficiency of 1D model in the calculation of a fine long canal and the accuracy of 3D model in the simulation of local open- channel blast flow，which can provide a better choice for analyzing complex open-channel flow problems in engineering.

Key words: hydraulic engineering, transient open-channel flow, numerical simulation, 1D and 3D coupling

摘要： 提出了一种一维浅水波与三维VOF模型耦合的明渠非恒定流数值计算方法。此方法通过建立两个计算模型间变量的数学关系，实现由三维区域为一 维区域提供流量，一维区域为三维区域提供压强和水体体积分数分布。用耦合方法模拟了矩形断面渠道增、甩负荷两种典型非恒定工况，将结果与一维浅 水波模型计算结果对比，表明本方法在定性上正确，在定量上准确度也较高。最后利用这一方法模拟了某水电站带引水渠压力前池的非恒定流现象，获得 了最大溢流量、最高和最低水位等重要参数。耦合方法同时结合了一维模型计算较细长明渠渐变流的效率和三维方法模拟局部明渠急变流的准确性，可为 分析工程中复杂的明渠流动问题提供更优选择。

关键词: 水利工程, 明渠非恒定流, 数值模拟, 一维与三维耦合