Vortex Patterns Investigation and Enstrophy Analysis in a Small Scale S-CO 2 Axial Turbine

Qiyu Ying, Weilin Zhuge, Yangjun Zhang, Can Ma, Jinlan Gou and Wei Wang
Additional contact information
Qiyu Ying: State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
Weilin Zhuge: State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
Yangjun Zhang: State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
Can Ma: Science and Technology on Thermal Energy and Power Laboratory, Wuhan 430205, China
Jinlan Gou: Science and Technology on Thermal Energy and Power Laboratory, Wuhan 430205, China
Wei Wang: Science and Technology on Thermal Energy and Power Laboratory, Wuhan 430205, China

Energies, 2021, vol. 14, issue 19, 1-22

Abstract: Supercritical carbon dioxide (S-CO 2 ) Brayton cycle system is a promising closed-loop energy conversion system frequently mentioned in the automotive and power generation field in recent years. To develop a suitable design methodology for S-CO 2 turbines with better performance, an understanding of the vortex flow patterns and associated aerodynamic loss inside a S-CO 2 turbine is essential. In this paper, a hundred-kilowatt level S-CO 2 axial turbine is designed and investigated using a three-dimensional transient viscous flow simulation. The NIST Span and Wagner equation of state model that considers the real gas effects is utilized to estimate the thermodynamic properties of the supercritical fluid. The numerical methods are experimentally validated. The results indicates that the aspect ratio and tip-to-hub ratio are different in the S-CO 2 turbine from that in the gas turbine, and the vortex flow patterns are influenced notably by these geometrical parameters. Both the vortex structure and moving tracks of passage vortices are changed as a result of large centrifugal force. An interaction between tip leakage vortex and hub passage vortex is observed in the impeller passage and its formation and development mechanism are revealed. To further explore the aerodynamic loss mechanism caused by vortex interaction, the energy loss in the impeller passage is analyzed with the enstrophy dissipation method, which can not only accurately calculate the energy loss but also estimate how the vortical motions occur. It is found that the enstrophy and energy loss can be effectively reduced by vortex interaction between tip leakage vortex and hub passage vortex. The results in this study would increase the knowledge of vortex flow patterns in S-CO 2 turbine and the proposed enstrophy production method can be used intuitively to provide a reference for flow vortical motion study in turbines.

Keywords: supercritical carbon dioxide; axial turbine; flow characteristic; vortex interaction; enstrophy dissipation analysis; energy loss (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2021
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/14/19/6112/pdf (application/pdf)
https://www.mdpi.com/1996-1073/14/19/6112/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:14:y:2021:i:19:p:6112-:d:643038

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().