Rotating stall mechanism of pump-turbine in hump region: An insight into vortex evolution

Lianchen Xu, Kan Kan, Yuan Zheng, Demin Liu, Maxime Binama, Zhe Xu, Xiaotong Yan, Mengqi Guo and Huixiang Chen

Energy, 2024, vol. 292, issue C

Abstract: Reversible Pump Turbines (RPTs) are primarily used in pumped-storage hydropower plants, enabling the facility to function in both pump and turbine modes. Under pump mode, the “hump region” refers to a characteristic range of flow conditions that are marked by large flow instabilities. These can eventually jeopardize the performance and operational safety of the plant. This study, through numerical simulation and model testing methods, examined the flow separation and rotating stall evolution mechanisms in the vaneless space and guide vane regions, for an RPT whose operating conditions are within the hump region. Applying the entropy production theory and Rortex method as energy loss and vortex identification methods, study results have shown that energy losses are concentrated at the guide vane's leading edge and vicinal zones, as well as within the draft tube. The energy loss within inter-guide vane flow passages is found to mainly take source from the experienced rigid water rotation at the same zones. Moreover, radial velocity differences, which are in turn linked to a non-uniform flow distribution among inter-guide vane passages, are believed to have considerably contributed the emergence of the rotating stall. Finally, the analysis of vortex flow evolution revealed the importance of flow separation-linked changes in entropy generation term in identifying the vortex evolution mechanism.

Keywords: Pump-turbine; Hump region; Energy loss; Rotating stall; Flow separation (search for similar items in EconPapers)
Date: 2024
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (3)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0360544224003517
Full text for ScienceDirect subscribers only

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:eee:energy:v:292:y:2024:i:c:s0360544224003517

DOI: 10.1016/j.energy.2024.130579

Access Statistics for this article

Energy is currently edited by Henrik Lund and Mark J. Kaiser

More articles in Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().