摘要
为了研究混流式水轮机转轮应力及变形情况,基于单向流固耦合理论,利用Workbench平台对其进行数值模拟.在模拟过程中首先利用ANSYS CFX软件,采用标准k-ε湍流模型对水轮机三维流态进行计算,其次通过Static Structural将流场水压力传递到转轮表面,进而进行耦合计算并得到了转轮应力和变形分布规律,最后通过试验结果对数值计算结果进行验证.研究表明:在100%开度下,从最低水头到额定水头、从额定水头到最高水头,转轮最大主应力与等效应力分别增大了9.8%,15.9%.另外在不同导叶开度下,水轮机转轮叶片瞬态较大变形、最大主应力以及最大等效应力均主要集中在叶片出水边与泄水锥交界处和叶片出水边靠近下环处,且随着导叶开度增大这些值均逐渐增大,特别在叶片出水边靠近下环处,由于该位置较薄,且在交变应力的反复作用下,该位置易发生疲劳破坏,因此更易出现裂纹和断裂.
In order to study the stress and strain of Francis turbine runner,the theory of one-way fluid-structure interaction was adopted,and the Workbench platform was employed to carry out numerical simulations.In the simulation process,firstly,the ANSYS CFX software and the standard k-εturbulence model were used to calculate the three-dimensional flow pattern in the turbine.Secondly,the flow field static pressure was transmitted to the runner solid surfaces by static structural module,and then a coupling simulation was performed,and the stress and deformation distribution rules of the runner were obtained.Finally,the numerical results were validated with the experimental results.The results show that at 100%opening,from the lowest head to the designed head,and from the designed head to the highest head,the maximum principal stress and equivalent stress of the runner increase by 9.8%and 15.9%,respectively.In addition,at different guide vane openings,the transient larger deformation,maximum principal stress and maximum equivalent stress of the turbine runner are mainly concentrated in the junction of the blade trailing edge and the cone(hub)and at the trailing edge near the shroud.Specially,with increasing guide vane opening,these values are amplified gradually,particularly,at the trailing edge near the shroud.Because that location is thinner,a fatigue failure is prone to occur there under the repeated action of an alternating stress.Nevertheless,cracks and fractures are more likely to appear there as well.
作者
史广泰
朱玉枝
刘宗库
李金
SHI Guangtai;ZHU Yuzhi;LIU Zongku;LI Jin(Key Laboratory of Fluid and Power Machinery,Ministry of Education,Xihua University,Chengdu,Sichuan 610039,China;School of Energy and Power Engineering,Xihua University,Chengdu,Sichuan 610039,China)
出处
《排灌机械工程学报》
EI
CSCD
北大核心
2020年第11期1119-1124,共6页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家重点研发计划项目(2018YFB0905200)
四川省教育厅科研项目(172470)
西华大学流体及动力机械教育部重点实验室开放课题项目(szjj2016-004)。
关键词
混流式水轮机
转轮
导叶开度
应力应变
数值计算
Francis turbine
runner
guide vane opening
stress and strain
numerical calculation
