Author(s): J Zhang; Y X Xiao; Q R Zhou; Z H Gui; B Guo; C J Zeng; Y Y Luo; H G Fan; Z W Wang

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Keywords: Pelton turbine; Water sheet flow; Super-high head; Numerical simulation; Free surface flow

Abstract: 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 the 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.

DOI: https://doi.org/10.1088/1755-1315/163/1/012067

Year: 2017