检索结果-南通市图书馆

Analysis of the vortices in the inner flow of reversible pump turbine with the new omega vortex identification method

引用

Journal of Hydrodynamics 2018年第3期30卷 463-469页

作者： Yu-ning Zhang Kai-hua Liu Jin-wei Li Hai-zhen Xian Xiao-ze Du Key Laboratory of Fluid and Power Machinery Ministry of EducationXihua UniversityChengdu 610039China Key Laboratory of Condition Monitoring and Control for Power Plant Equipment(Ministry of Education) North China Electric Power UniversityBeijing 102206China Beijing South-to-North Water Diversion Tuancheng Lake Management Office Beijing 100195China China Institute of Water Resources and Hydropower Research Beijing 100048China

Reversible pump turbines are widely employed in the pumped hydro energy storage power plants. The frequent shifts among various operational modes for the reversible pump turbines pose various instability problems, e.g., the strong pressure fluctuation, the shaft swing, and the impeller damage. The instability is related to the vortices generated in the channels of the reversible pump turbines in the generating mode. In the present paper, a new omega vortex identification method is applied to the vortex analysis of the reversible pump turbines. The main advantage of the adopted algorithm is that it is physically independent of the selected values for the vortex identification in different working modes. Both weak and strong vortices can be identified by setting the same omega value in the whole passage of the reversible pump turbine. Five typical modes（turbine mode, runaway mode, turbine brake mode, zero-flow-rate mode and reverse pump mode） at several typical guide vane openings are selected for the analysis and comparisons. The differences between various modes and different guide vane openings are compared both qualitatively in terms of the vortex distributions and quantitatively in terms of the areas of the vortices in the reversible pump turbines. Our findings indicate that the new omega method could be successfully applied to the vortex identification in the reversible pump turbines.

关键词： Reversible pump turbine vorticity vortex identification omega method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Stretching and shearing contamination analysis for Liutex and other vortex identification methods

引用

Advances in Aerodynamics 2021年第1期3卷 166-185页

作者： Pushpa Shrestha Charles Nottage Yifei Yu Oscar Alvarez Chaoqun Liu Department of Mathematics The University of Texas at ArlingtonArlingtonTX 76019USA

The newly developed vortex-identification method,Liutex,has provided a new systematic description of the local fluid rotation,which includes scalar,vector,and tensor ***,the advantages of Liutex over the other widely used vortexidentification methods such as Q,Δ,λ2,andλci have not been *** traditional methods count on shearing and stretching as a part of vortex ***,in the real flow,shearing and stretching do not contribute to fluid *** this paper,the decomposition of the velocity gradient tensor is conducted in the Principal Coordinate for *** the contamination effects of stretching and shearing of the traditional methods are investigated and compared with the Liutex method in terms of mathematical analysis and numerical *** results show that the Liutex method is the only method that is not affected by either stretching or shear,as it represents only the local fluid rigid *** results provide supporting evidence that Liutex is the superior method over others.

关键词： Liutex Vorticity Vortex omega method Transition flow Velocity gradient tensor Principal coordinate Principal tensor Liutex tensor decomposition

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：