Flow characteristics on the blade channel vortex in the Francis turbine

[摘要] Depending on the long-term hydraulic development of Francis turbine, the blade channel vortex phenomenon was investigated systematically from hydraulic design, experimental and numerical computation in this paper. The blade channel vortex difference between the high water head and low water head turbine was also analyzed. Meanwhile, the relationship between the blade channel vortex and the operating stability of hydraulic turbine was also investigated. The results show that the phenomenon of blade channel vortex is an intrinsic property for Francis turbine under small flow rate condition, the turning-point of the blade channel vortex inception curve appears at low unit speed region, and the variation trend of the blade channel vortex inception curve is closely related to the blade inlet edge profile. In addition to, the vortex of the high water head turbine can generally be excluded from the stable operation region, while which is more different for the one of the low water head turbine.

[发布机构] State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area, Xi'An University of Technology, Xi'an, Shaanxi Province; 710048, China^1;Dongfang Electric Machinery Co., Ltd., Deyang, Sichuan Province; 618000, China^2

[效力级别] 工业技术 [学科分类] 工业工程学

[关键词] Blade channels;Flow charac-teristics;Hydraulic designs;Intrinsic property;Numerical computations;Operating stability;Small flow-rate;Stable operation