Abstract：With consideration of the influence of transient flow in pipe during a transition of operation condition, a coupled calculation model for the transient flow in a pipe and threedimensional unsteady flow in a turbine was developed in this paper. The transient flow in pipe was calculated by the characteristic method and the unsteady flow in the turbine was calculated by the finite volume method for threedimension incompressible flows. A coupled iteration was carried on at the interface between the pipe and the turbine based on the continuity of flow and the balance of total pressure of water. Three methods, including coupled calculation method, traditional transient simulation method and traditional threedimensional flow calculation method, were used to simulate the loadrejection transient process of a hydraulic turbine with diversion penstock. The results showed that the trends of pressure, flow of unit and rotational speed, etc, are consistent in all three methods. However, because the reflection and superposition of water hammer wave is considered in the coupled calculation method, the increase in water hammer pressure at the spiral inlet is higher and the pressure fluctuation in the turbine is stronger, suggesting the method can reflect the interaction between transient flow in the pipe and threedimension unsteady flow in the turbine more realistically.
［1］Zobeiri A,Kueny J L,Farhat M, et al. Pumpturbine rotorstator interaction in generating mode: pressure fluctuation in distributor channel［C］／／Proceedings of 23rd IAHR Symposium on Hydraulic Machinery and systems. Yokohama:［s.n.］,2006.［2］Liu Shuhong, Zhou Daqing, Liu Demin,et al. Runaway transient simulation of a model kaplan turbine［C］／／Proceedings of 25th IAHR Symposium on Hydraulic Machinery and Systems. Timisoara:［s.n.］,2010.［3］Li Jinwei, Yu Jixing, Wu Yulin.3D unsteady turbulent simulations of transients of the francis turbine［C］／／Proceedings of 25th IAHR Symposium on Hydraulic Machinery and Systems. Timisoara:［s.n.］,2010.［4］李凤超.可逆式水力机组流动控制研究［D］.北京：清华大学热能工程系,2011.［5］陈乃祥.水利水电工程的水力瞬变仿真与控制［M］. 北京: 中国水利水电出版社,2004.［6］常近时.水轮机全特性曲线及其特征工况点的理论确定方法［J］.北京农业工程大学学报, 1995, 15(4): 77-83.Chang Jinshi. Analysis of whole characteristic curve and their special condition points in mixedflow pumpturbine［J］.Journal of Beijing Agricultural Engineering University, 1995, 15(4): 77-83. (in Chinese)［7］袁义发.调压室、机组三维非定常流动与管道瞬变流耦合计算［D］.北京：清华大学热能工程系，2010.［8］Magnoli M V, Schilling R. Vortex shedding in francis runners trailing edges ［C］／／Proceedings of 24th IAHR Symposium on Hydraulic Machinery and systems. FozdoIguassu:［s.n.］,2008.
