摘要
在保证CFD模拟长短叶片混流式水轮机可靠性的基础上,通过改变蜗壳进口流量,模拟得到了水轮机历经额定运行、甩负荷、部分负荷稳定运行、增负荷和额定运行五个阶段的尾水涡带演变规律.结果表明:长短叶片水轮机偏负荷工况不会形成常规混流式水轮机的螺旋涡带,尾水管边壁压力脉动幅值较小.采用Q准则和本征正交分解(POD)方法分析尾水涡带结构,当流量改变时,主流在尾水管中心和边壁之间转移,伴随复杂的涡带结构演变.随着负荷减小,单一柱状涡带、多级缠绕螺旋涡带和管壁处多股片状螺旋涡结构所携带能量依次增强,在部分负荷时管壁处螺旋涡结构能量占比达到8%以上.
Based on the reliability of simulating the Francis turbine with splitter blades using the CFD method, five stages including rated condition, load rejection, part load condition, increasing load and back to rated condition were calculated by changing the flow rate at the inlet of the spiral case. The results show that the spiral vortex band usually observed in the conventional Francis turbine does not appear in the turbine with splitter blades. Meanwhile the pressure pulsations on the wall of the draft tube are small. The Q criterion and the POD method were adopted to classify the vortex structures in the draft tube, and it is found that the main flow moves between the center and the side wall of the draft tube and complex vortex structures vary as the flow decreases. Besides, the power that carried by the single columnar vortex band, the multiple twisted vortex bands and the flake vortex bands at the side wall increase when the load decreases, and the power of the flake vortex bands at the side wall at part load can reach more than 8%.
作者
张春泽
刁伟
尤建锋
夏林生
Zhang Chunze Diao Wei You Jianfeng Xia Linsheng(Southwest Institute of Water transport Engineering, Chongqing J iaotong University, Chongqing 400016, China State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China)
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2017年第7期66-73,共8页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(51579187)
重庆市科委自然科学基金资助项目(cstc2016jcyjA1935)
重庆市教委自然科学基金资助项目(KJ1600514)
重庆交通大学内河航道整治技术交通行业重点实验室开放基金资助项目(NHHD-201505)
关键词
混流式水轮机
长短叶片
压力脉动
尾水涡带
Q准则
本征正交分解
francis turbine
splitter blades
pressure pulsations
vortex ropes
Q criterion
proper orthogonal decomposition （POD）
