Numerical analysis of a Pelton runner water sheet flow under super-high head

Asian Working Group- IAHR's Symposium on Hydraulic Machinery and Systems

Zhang, J.^1 ; Xiao, Y.X.^1 ; Zhou, Q.R.^1 ; Gui, Z.H.^2 ; Guo, B.^1 ; Zeng, C.J.^1 ; Luo, Y.Y.^1 ; Fan, H.G.^1 ; Wang, Z.W.^1

State Key Laboratory of Hydroscience and Engineering, Department of Thermal Engineering, Tsinghua University, Beijing

100084, China^1

Technology Center State Grid Xinyuan Company LTD., Beijing

100032, China^2

关键词: Evolution history;    Free-surface flow;    Homogeneous models;    Hydraulic mechanism;    Hydraulic performance;    Pressure coefficients;    Reaction turbines;    Unsteady numerical simulations;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/163/1/012067/pdf
DOI  :  10.1088/1755-1315/163/1/012067

来源: IOP

【 摘 要 】

The hydraulic performance of Pelton turbine is different from reaction turbines due to its unsteady flow of rotating buckets with time and space. The water sheet flow in Pelton turbine is also very complex as the jet flow is often interacted with air and itself. This paper numerically investigates the dynamic hydraulic performance of a Pelton under super-high head. Unsteady numerical simulations were performed using SST k-ω. Two-phase homogeneous model and VOF were adopted to model he free surface flow. The evolution history of water sheet flow in the buckets were presented. The distribution of pressure coefficient on the bucket surface were also analysed. The results indicate that the development of water sheet flow on the bucket surface can be divided into three stages, corresponding to the output power variation process. This calculation can be used to illustrate the hydraulic mechanism of water sheet flow evolution.