中文摘要：

本文以有角加速度的旋转参考坐标系下的流体控制方程和管道瞬变流的特征线法计算模型为基础，针对机组蜗壳前连接有引水管道的水力发电系统，建立了管道瞬变流与机组内部三维流动的耦合计算模型，成功地应用该模型实现了电站甩负荷的过渡过程计算，并与管道和机组都采用三维不可压流动的有限体积法求解的计算结果进行了比较分析，比较结果表明，耦合模型能计及管道中水击波的反射和叠加作用，更好地反映引水管道内水击现象与机组内部的三维非定常流动的相互影响。

英文摘要：

This paper develops a coupling transient flow model for transient pipe flows and three-dimensional turbine flows, based on the fluid governing equation in an accelerated rotational coordinate system and the characteristic method. This model was used for simulation of load-rejection transient of a turbine system with a long pipe in a hydropower plant, with the pipe flow being modeled and the load-rejection transient in the turbine being calculated by a three-dimensional viscous model of impressible fluid. A comparison of the calculations with full 3D modeling of the pipe and turbine flows shows that the coupling model gives good results of the superposition and reflection behaviors of the water hammer waves and it better reflects the interrelationship of water hammer in the pipe and unsteady flow in the turbine.