Evolution of large-scale flow structures in an axial-flow pump during performance breakdown DOI
Lei Wang,

Shaoxuan Kang,

Yaojun Li

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(9)

Published: Sept. 1, 2024

This paper presents a very large eddy simulation analysis of the unsteady flow in pre-stall to stall transition process an axial-flow pump, with aim elucidate spatiotemporal evolution large-scale structures during performance breakdown pump. The transient is investigated utilizing time-dependent rate computation scheme. results demonstrate that, as dynamically reduced, reduction pump head found lags behind by approximately 15 impeller revolutions. leading edge separation on blade suction side (SS) evolves into vortex (LSV) conjunction dynamic rate. attached SS vicinity hub and trailing squeezes mainstream outwards, resulting formation cross passage (CPV) tip passage. combined effect LSV, CPV, tip-clearance induces penetrating upstream region impeller, which gives rise swirling backflow within inlet pipe. At stall, CPV stably extends neighboring blade. Furthermore, observed near junction hub, it collides inflow hub-attached vortex.

Language: Английский

Effect of pressure-balance pipes on the axial hydraulic thrust of a reversible pump-turbine under the runaway condition DOI

Shuangqian Han,

Zhenmu Chen, Haoru Zhao

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(2)

Published: Feb. 1, 2025

Axial hydraulic thrust is a crucial factor contributing to the unstable operation of pump-turbine especially under off-design conditions. Pressure-balance pipe can effectively achieve axial balance pump-turbine. In this study, impact diameter and location pressure-balance on runaway condition investigated. The influence mechanism pressure distribution internal flow patterns further explored. results show that pipes have relatively minor while increase in causes rise thrust. Compared with outer pipe, inner demonstrates more significant effect force runner. Additionally, low-frequency components at 0.6 times runner rotational frequency are observed, which indicate occurrence stall vaneless area. variation also affects number passages vortices, as well quantity vortices. With diameter, backflow phenomena negative regions gradually emerge result chaotic flow.

Language: Английский

Citations

1
Comprehensive assessment and analysis of cavitation scale effects on energy conversion and stability in pumped hydro energy storage units DOI
Haoru Zhao, Baoshan Zhu, Bo Jiang

et al.

Energy Conversion and Management, Journal Year: 2024, Volume and Issue: 325, P. 119370 - 119370

Published: Dec. 12, 2024

Language: Английский

Citations

8
Numerical investigation of internal flow characteristics in an azimuth waterjet propulsion at different ship speeds DOI Creative Commons
Peng Yan, Ruizhi Zhang,

Kunyu Meng

et al.

Applied Ocean Research, Journal Year: 2025, Volume and Issue: 154, P. 104406 - 104406

Published: Jan. 1, 2025

Language: Английский

Citations

0
Development of firefighting systems for coastal facilities using water-jet powered fire boats DOI Creative Commons

Nail Abdullin,

Ildar F. Khafizov,

Dmitriy Petrovich Alekseev

et al.

E3S Web of Conferences, Journal Year: 2025, Volume and Issue: 627, P. 05023 - 05023

Published: Jan. 1, 2025

The article is devoted to the analysis of fires and their extinguishing at coastal facilities using mobile fire departments ensure safety people, property environment. authors considered effective specialized methods technologies, including use boats with a water jet engine. parameters operation pump hose systems were calculated, maximum distance from site rescue boat distribution forces means protection units determined.

Language: Английский

Citations

0
Evolution of large-scale flow structures in an axial-flow pump during performance breakdown DOI
Lei Wang,

Shaoxuan Kang,

Yaojun Li

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(9)

Published: Sept. 1, 2024

This paper presents a very large eddy simulation analysis of the unsteady flow in pre-stall to stall transition process an axial-flow pump, with aim elucidate spatiotemporal evolution large-scale structures during performance breakdown pump. The transient is investigated utilizing time-dependent rate computation scheme. results demonstrate that, as dynamically reduced, reduction pump head found lags behind by approximately 15 impeller revolutions. leading edge separation on blade suction side (SS) evolves into vortex (LSV) conjunction dynamic rate. attached SS vicinity hub and trailing squeezes mainstream outwards, resulting formation cross passage (CPV) tip passage. combined effect LSV, CPV, tip-clearance induces penetrating upstream region impeller, which gives rise swirling backflow within inlet pipe. At stall, CPV stably extends neighboring blade. Furthermore, observed near junction hub, it collides inflow hub-attached vortex.

Language: Английский

Citations

0