An outlook on the draft-tube-surge study

M Nishi, S Liu - International Journal of Fluid Machinery and Systems, 2013 - jstage.jst.go.jp
If large pressure fluctuation is observed in the draft tube of a Francis turbine at part-load
operation, we have generally called it draft-tube-surge. As occurrence of this phenomenon …

Part load vortex rope as a global unstable mode

S Pasche, F Avellan, F Gallaire - Journal of fluids …, 2017 - asmedigitalcollection.asme.org
Renewable energy sources (RES) have reached 23.7% of the worldwide electrical
generation production in 2015. The hydraulic energy contribution amounts to 16.6% and …

Swirling flow in a hydraulic turbine discharge cone at different speeds and discharge conditions

S Skripkin, M Tsoy, P Kuibin, S Shtork - Experimental Thermal and Fluid …, 2019 - Elsevier
An experimental investigation of the cavitating turbulent flow in a simplified hydraulic turbine
was carried out to examine flow features in a wide range of speed and discharge conditions …

Experimental study of mitigation of a spiral vortex breakdown at high Reynolds number under an adverse pressure gradient

R Goyal, BK Gandhi, MJ Cervantes - Physics of fluids, 2017 - pubs.aip.org
The flow in the off-design operation of a Francis turbine may lead to the formation of spiral
vortex breakdowns in the draft tube, a diffuser installed after the runner. The spiral vortex …

Study of vortex rope for the flow field pulsation law

F Jin, P Li, R Tao, R Xiao, D Zhu - Ocean Engineering, 2023 - Elsevier
When a hydro turbine deviates from the best efficiency conditions and carries the partial
load, the helical vortex rope appears in the center of the draft tube. It will cause the unstable …

Forced and self oscillations of hydraulic systems induced by cavitation vortex rope of Francis turbines

S Alligné - 2011 - infoscience.epfl.ch
With economical energy market strategies based on instantaneous pricings of electricity as
function of the demand or the predictions, operators harness more hydroelectric facilities to …

一种水力机械压力脉动的分频模态提取方法及应用

周济宸, 牛翔宇, 林贵海, 刘鑫 - 水力发电学报, 2023 - slfdxb.cn
水力机械在偏离最优工况条件下, 水压脉动可能包含多种频率成分, 对流场时域分析时,
小幅值次主频率成分的非定常演变特征常被主频成分的时域演变所掩盖. 本文借鉴结构动力学中 …

[图书][B] Simulation, analysis, and mitigation of vortex rope formation in the draft tube of hydraulic turbines

H Foroutan - 2015 - search.proquest.com
Flow in the draft tube of a hydraulic turbine operating under off-design conditions is very
complex. The instability of the swirling flow may lead to the formation of a helical precessing …

Pressure oscillation suppression by air admission in a Francis turbine draft tube

X Luo, A Yu, W Yu, L Wang, H Xu - IOP Conference Series: Earth …, 2019 - iopscience.iop.org
When Francis turbine operated at part-load conditions, there is strong vortex rope in the draft
tube, which may induce violent pressure oscillation, mechanical vibration and noise. This …

Experimental and numerical analysis of the cavitating part load vortex dynamics of low-head hydraulic turbines

S Houde, MS Iliescu, R Fraser… - Fluids …, 2011 - asmedigitalcollection.asme.org
The draft tube flow is a two-sided challenge for the operation of a hydraulic turbine. On one
side, it is an important component for the performance of low to medium head turbines …