Rotational stall and pressure fluctuations in centrifugal pump impellers with transient flow rates DOI
Xiao-Ping Chen, Xiaojie Zhou, Yu Li

и другие.

Physics of Fluids, Год журнала: 2025, Номер 37(3)

Опубликована: Март 1, 2025

To investigate the characteristics of rotational stall and pressure fluctuations, this study presents two large eddy simulations for five-blade seven-blade centrifugal pump impellers under transient condition. The condition represents that flow rate speed are sinusoidal constant, respectively. Research shows processes germination, transition stabilization clearly discerned in evolution during both dropping rising stages. increase number blades enhances uniformity time-averaged normal vorticity distributions among different passages has negligible influence on total vorticity. low-frequency fluctuations range impeller is greater compared to impeller. high-frequency components intense primarily at leading trailing edges blade, especially when instantaneous below half load. first-order dominant frequency identical inlet passages, results a reduction amplitude.

Язык: Английский

Flow Characteristics and Pressure Pulsation Analysis of Cavitation Induced in a Double-Volute Centrifugal Pump DOI Open Access

Yongsha Tu,

Xueying Zhao, Lifeng Lu

и другие.

Water, Год журнала: 2025, Номер 17(3), С. 445 - 445

Опубликована: Фев. 5, 2025

Cavitation is a complex multiphase flow phenomenon, and the generation of transient phase transitions between liquid vapor during cavitation development leads to multi-scale vortex motion. The dynamics centrifugal pump’s rotor–stator interaction will induce pressure fluctuations in impeller volute fluid pump, resulting field structure. Based on Schnerr–Sauer model SST k-ω turbulence model, this paper studies characteristics cavitation-induced unsteady pump excitation response pulsation under different conditions, taking large vertical double-volute as research object. results indicate following: As rotates, external response, jet-wake structure at blade outlet shows an increase frequency signal. This evident near measurement points tongue separator. When severe occurs, maximum amplitude shifts from (30°) downstream (45°). value fpmax 3.1 times that when NPSHa = 8.88 m. By applying Omega identification method, it can be seen vortices trailing edge stable undergoes process elongation, fusion, separation, recovery. represents influence volute. Q 0.9Qd, passage tail detaching dissipating path observed, demonstrating upstream impeller.

Язык: Английский

Процитировано

1

Study on rotating stall characteristics of centrifugal pumps based on gamma transition model DOI Creative Commons
Changliang Ye, Wan‐Ru Huang,

Hongyeyu Yan

и другие.

Physics of Fluids, Год журнала: 2024, Номер 36(5)

Опубликована: Май 1, 2024

The phenomenon of rotating stall in centrifugal pumps is closely associated with the evolution blade boundary layer. Aiming to accurately predict characteristics layer, this study investigates pump impellers using gamma (γ) transition model. accuracy numerical simulation was confirmed by comparing its conclusions results testing. In calculations considering characteristics, distribution low-pressure areas inside impeller relatively discontinuous, while pressure more uniform. However, without transition, regions neighboring flow channels exhibit a tendency be interconnected, resulting variable distribution, and contour at outlet closer parallel. dynamic were obtained through mode decomposition method, including frequency, structure, process vortex. Through modal reconstruction, it discovered that impeller's rotation causes vortex undergo periodic fluctuations. not stationary but moves synchronously blades. At different time points, exhibits changes. suction entrance, initially appears. Subsequently, multiple structures resulted channel blockage. After period development, excess merge generate typical “8” shaped structure move toward exit. Finally, exit disappears, new generated inlet surface.

Язык: Английский

Процитировано

4

Assessment of viscosity effects on high-speed coolant pump performance DOI Creative Commons
Dongcheng Wang, Yandong Gu, Christopher Stephen

и другие.

Physics of Fluids, Год журнала: 2024, Номер 36(5)

Опубликована: Май 1, 2024

The high-speed coolant pump facilitates thermal regulation in electric vehicle components, including batteries and motors, by circulating an ethylene glycol solution. This commonly used fluid exhibits a notable negative correlation with temperature terms of viscosity. Numerical simulations investigate the transient dynamics operating at 6000 rpm, driving flow various temperatures. A test rig is established, performance evaluated under different conditions. numerical temperatures align well experimental outcomes. Decreasing temperatures, from 100 to −20 °C, lead reduced head efficiency due increased Specifically, rate 30 L/min, decreases 40.03% 44.19%. With escalating viscosity, best point shifts toward lower rates. Notable impacts on both disk hydraulic are observed viscosity fluctuations. It exerts minimal influence volumetric elevated rates but has substantial impact Increased causes uneven pressure distribution within pump, altering velocity profiles impeller. High-viscosity fluids tend form large-scale vortex structures around blades, reducing thrust exerted blades fluid. Higher results larger increasing frictional resistance. study findings provide valuable insights for advancement high-efficiency, energy-saving, pumps tailored vehicles.

Язык: Английский

Процитировано

4

Frictional drag and turbulent dissipation in a water-ring vacuum pump DOI
Heng Li

Physics of Fluids, Год журнала: 2025, Номер 37(1)

Опубликована: Янв. 1, 2025

The water-ring vacuum pump is a crucial piece of negative pressure extraction equipment, extensively utilized in gas and wind tunnel applications. While pumps offer numerous advantages, including safety reliability, they also present drawbacks such as low efficiency high energy consumption. operational these one their most significant performance indicators serves the foundation for evaluating Enhancing currently at forefront research area interest. influenced by multiple factors. This article focuses on two critical factors that impact water ring pumps: casing friction turbulent dissipation. study employs theoretical analysis simulation to compare under both rotating non-rotating conditions, thereby analyzing power loss associated with dissipation within ring. At an ideal impeller speed 3000 r/min, corresponding characteristic Reynolds number Re = 1.88 × 105. results indicate (1) consumed 0.4 kW, while lost due amounts 1.2 kW; (2) when rotates 1000 consumption decreases 0.16 representing reduction approximately 60%; from drops reflecting 87% decrease; (3) 2000 further 0.056 86%. 0.046 indicating 96%. presents finding rotation can markedly weaken dissipation, providing valuable insights design high-efficiency pumps.

Язык: Английский

Процитировано

0

Rotational stall and pressure fluctuations in centrifugal pump impellers with transient flow rates DOI
Xiao-Ping Chen, Xiaojie Zhou, Yu Li

и другие.

Physics of Fluids, Год журнала: 2025, Номер 37(3)

Опубликована: Март 1, 2025

To investigate the characteristics of rotational stall and pressure fluctuations, this study presents two large eddy simulations for five-blade seven-blade centrifugal pump impellers under transient condition. The condition represents that flow rate speed are sinusoidal constant, respectively. Research shows processes germination, transition stabilization clearly discerned in evolution during both dropping rising stages. increase number blades enhances uniformity time-averaged normal vorticity distributions among different passages has negligible influence on total vorticity. low-frequency fluctuations range impeller is greater compared to impeller. high-frequency components intense primarily at leading trailing edges blade, especially when instantaneous below half load. first-order dominant frequency identical inlet passages, results a reduction amplitude.

Язык: Английский

Процитировано

0