Analysis of flow and energy dissipation in pump turbine with small guide vane opening

Autor: Jiahao Lu, Ran Tao, Wei Xiao, Zhonghua Gui, Di Zhu, Ruofu Xiao, Weichao Liu
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Engineering Applications of Computational Fluid Mechanics, Vol 18, Iss 1 (2024)
Druh dokumentu: article
ISSN: 19942060
1997-003X
1994-2060
DOI: 10.1080/19942060.2024.2421481
Popis: In this study, a detailed flow state analysis of a reversible pump turbine (RPT) under small guide vane opening conditions was conducted using both numerical simulation and experimental methods on three analysis planes at 0.5 span. The entropy production rate (EPR) in entropy production theory was utilized to visualize the location and magnitude of energy losses in the flow process. The focus was placed on the coherent vortex structures in the volute, stay vane, guide vane, and runner flow path. The results demonstrate that, throughout the runner’s cycle, the leading edge of the guide vane experiences low-pressure regions with uneven pressure distribution within the runner channel. Velocity streamlines reveal flow separation and vortex generation at the typical guide vane trailing edge, with a maximum velocity reaching 49.7. Analysis of radial force and torque on typical guide vanes and the runner indicates that radial force and torque on the guide vanes do not significantly change, with the radial force coefficient CFr−x varying between 0.254 and 1.3. Major energy losses are concentrated behind the trailing edge of the guide vane, primarily in the form of jet wake. Coherent vortex structures are observed in the volute, stay vane, guide vane, and runner flow path, with slight turbulent wake at the trailing edge of the stay vane, clear shedding vortex streets, and vortex build-up in the bladeless area between the guide vane and the runner.
Databáze: Directory of Open Access Journals