Fatigue analysis in rotor of a prototype bulb turbine based on fluid-structure interaction
Fatigue analysis in rotor of a prototype bulb turbine based on fluid-structure interaction
复制标题
基于流固耦合的原型灯泡式水轮机转子疲劳分析
DOI：
10.1016/j.engfailanal.2021.105940
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发表时间：
2021-11
影响因子：
4
通讯作者：
Yan Liu
中科院分区：
文献类型：
--
作者：
Jingwei Cao;Hong Tian;S H Ahn;Wenzhi Duo;Huili Bi;Lin Zhao;Guozheng Zhao;Haiyu Gao;Mingming Wang;Guoming Ma;Zhengwei Wang;Yan Liu
• The fatigue analysis of a bulb turbine rotor is carried out. • Fluid-structure interaction method is used. • The linear elastic fracture mechanics theory is used to analyze the cracked zone stress. • The structural weight is the main contribution of stress amplitude. • Tiny defects generated by welding and erosion result in failure. Bulb turbine units are widely used in run-of river or dam projects with relatively low head, and can also be used for tidal energy utilization. Some types of bulb turbines have excessive vibration and fatigue failure problems, which threats their fatigue life. The model analyzed in this paper is a prototype bulb turbine rotor which suffered cracks, probably due to erosion and welding defects. The dynamic stress characteristics are analyzed under not only the non-cracked shaft condition but also the cracked one, to find possible causes of the failure. The computational fluid dynamics (CFD) simulation is performed to obtain reliable hydraulic load on the runner for performing the FEM analysis. The CFD results are verified by comparing with the site test for the prototype one. The linear elastic fracture mechanics theory combined with the fluid-structural interaction theory is applied to developing a cracked FEM model, to obtain the dynamic stress characteristics for the runner, shaft and rotor. The results reveal that the change in dynamic stress level on the shaft flange root significantly depends on the operating conditions, and the stress amplitude on the shaft mainly depends on the structural weight. The stress at the cracked zone could be up to 376.5 MPa in the best efficiency point, with only 1.5 years of fatigue life. Based on the numerical calculations and site inspection, it could be concluded that the insufficient sealing could lead to leakage flows with specific flow rates in flange root, which resulted in the occurrence of erosion; in addition, the welding at the flange root probably generated tiny defects. These two factors are likely lead to fatigue cracks and major failure of the shaft. Suggestions for solutions for the problems of the shaft are also discussed. Results of this study helps to find the reasons of the shaft fatigue failure. Furthermore, the analysis method could be used for an accurate calculation of fatigue life and providing guidance in future designs and operations of bulb turbine units.
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影响因子：
15.9
作者：
C. Trivedi;M. Cervantes
通讯作者：
C. Trivedi;M. Cervantes
BEM-CFD 与全转子几何模拟对海流涡轮机性能和流场的比较
影响因子：
8.7
作者：
Qiang Guo;Lingjiu Zhou;Zhengwei Wang
通讯作者：
Zhengwei Wang
影响因子：
2.1
作者：
X. Ge;Yuanshuo Feng;Ye Zhou;Yuan Zheng;Chunxia Yang
通讯作者：
X. Ge;Yuanshuo Feng;Ye Zhou;Yuan Zheng;Chunxia Yang
DOI：
10.2514/6.1994-2343
发表时间：
1994-06
期刊：
--
影响因子：
--
作者：
F. Menter;C. Rumsey
通讯作者：
F. Menter;C. Rumsey
影响因子：
4
作者：
Urquiza, G.;Garcia, J. C.;Mendoza, O. F.
通讯作者：
Mendoza, O. F.