Author(s): Demin Liu; Xiaobing Liu; Haiku Zhang
Linked Author(s):
Keywords: Channel vortex; Cavitation; Turbine
Abstract: Channel vortex, a common phenomenon in giant Francis turbine，must be out of the range of operating zone of hydraulic turbine in the contract provision. Does the channel vortex have similar potential hazard with draft tube vortex to the turbine? Is it valued to pay more attention to this vortex? What’s the amplitude and frequency of channel vortex? In this paper, we present the experiment and numerical simulation results for channel vortex, adopting cavitation model to predict the channel vortex initial line as well as developed line. The starting location in the runner channel includes two types, one starts on the inlet of blade while the other lies at the band of the blade. The mismatch between inlet flow angles and blade mounting angles is the reason of channel vortex taking place. Vortex evolution mainly includes vortex stretching which the main reason of the vortex is moving from runner inlet to out of the runner, and vortex expanding which is the leading cause of the vortex crushing damage to the runner blades.
Year: 2013