The Spatio‐Temporal Characteristics of Flow Field Inside a Self‐Priming Pump During the Self‐Priming Process DOI Creative Commons
Yuliang Zhang, Jingfu Li, Yan‐Juan Zhao

et al.

Energy Science & Engineering, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 29, 2024

ABSTRACT In this article, a closed‐loop piping system that includes the self‐priming pump is established and calculated. Two operating processes reflecting real situations are accurately calculated by means of UDF. The vortex identification method, entropy production theory, energy gradient method employed to deeply analyze reveal loss characteristics flow stability. results show in oscillating exhaust stage, greatest during stage process. reflux hole, tongue, outlet section volute have larger loss. Within impeller region, mainly concentrated at inlet outlet; distribution area value clearance wear‐ring. addition, instability region left side significantly than rest locations increases considerably with

Language: Английский

Research on the flow characteristics and energy variation characteristics of the outlet passage of a two-way flow pump device based on Liutex and energy balance equation method DOI
Yuqi Wang, Li Cheng

Energy, Journal Year: 2025, Volume and Issue: 318, P. 134805 - 134805

Published: Jan. 31, 2025

Language: Английский

Citations

1
Stabilize cloud cavitation with an obstacle near hydrofoil's trailing edge and conduct local entropy production analysis DOI Open Access
Lu Wang, Jintao Liu, Wen Li

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(1)

Published: Jan. 1, 2024

Cloud cavitation always causes severe damage to the efficiency and stability of hydraulic machinery, resulting in extra energy losses system. We have observed an effective simple way prevent cloud formation by placing obstacle near hydrofoil's trailing edge. Cavitating flows around four different types hydrofoils were simulated using stress-blended eddy simulation turbulence model: National Advisory Committee for Aeronautics (NACA) 66 hydrofoil NACA with a 1 ×1 mm2 at 0.3c, 0.5c, or 0.7c. Sheet is predominant mode cavity flow when obstruction positioned To find out why growth can be stopped 0.7c, velocity field, vorticity Z direction, vortex structure Q-criterion computed. study loss comprehend how obstacles affect it, local entropy production rate was It discovered that downstream obstacle, restructured, which helps manage separation upstream obstacle. Consequently, suction surface nearly rotates same direction as Vx positive X axis, indicating reentrant has been controlled 0.7c Furthermore, shedding are strongly correlated, regulating advantageous conservation.

Language: Английский

Citations

8
Energy loss evaluation in radical inflow turbine based on entropy production theory and orthogonal experiment method DOI Open Access
Zhiqi Wang,

Huya Yang,

Xin Li

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(2)

Published: Feb. 1, 2024

The fluctuation of heat source conditions results in off-design operation the radial inflow turbines (RIT) organic Rankine cycle. However, flow loss characteristics RIT under have not been completely revealed. entropy production theory has advantage determining quantity and location energy dissipation, which is used to evaluate different conditions. In addition, order operating parameters on determined by orthogonal experimental method. show that each term components increase with inlet pressure temperature, while they decrease outlet RIT. Under conditions, turbulent dissipation wall are main cause loss, closely related vortices high velocity gradients field. rotor diffuser contribute volume-average area-average stator higher than those other components. shear dominants loss. greatest impact dissipation.

Language: Английский

Citations

7
Effect of inlet gas volume fraction on shafting vibration of multiphase pumps under low discharge conditions DOI
Guojun Zhu,

Zhenbo Tang,

Jianjun Feng

et al.

Ocean Engineering, Journal Year: 2024, Volume and Issue: 294, P. 116803 - 116803

Published: Jan. 25, 2024

Language: Английский

Citations

3
Numerical investigation of no-load startup in a high-head Francis turbine: Insights into flow instabilities and energy dissipation DOI Open Access
Longgang Sun, Lei Liu, Zhuofei Xu

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(3)

Published: March 1, 2024

The presented paper numerically investigates the internal flow behaviors and energy dissipation during no-load startup process toward a Francis turbine. Passive runner rotation is implemented through angular momentum balance equation accompanied by dynamic mesh technology user defined function. Three phases of rotational speed are identified: stationary, rapid increase, slow increase. Head exhibits monotonic decrease, rise fall, eventual fluctuation. Flow rate shows quasi-linear pressure fluctuations in vaneless region primarily dominated frequencies induced Rotor-Stator Interaction broad frequency range below 50 Hz, 30 Hz draft tube. Runner inlet experiences positive to negative incidence angles, causing intense separation unstable structures. Draft tube large-scale recirculation evolving vortex Energy loss analysis based on entropy production method highlights as primary contributors. within an initial subsequent then again stationary increase phases. While phase Turbulent significantly contribute loss, with trends matching total production. Maximum locations correspond wall, emphasizing importance generation. This study establishes foundational insights into hydrodynamics modes hydraulic turbine startup, paving way for further research.

Language: Английский

Citations

3
Vortex energy behaviors in the forebay of lateral pumping station for Y-type channel DOI
Can Luo, Li Zhang,

Tieli Wang

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(7)

Published: July 1, 2024

Vortices always happen in the forebay and sump of a lateral pumping station, reducing its efficiency wasting extra electric power. This study utilizes computational fluid dynamics (CFD) technology model test method to investigate distribution vortices station Y-shaped channel. Since vortex is accompanied by energy dissipation, entropy production theory also introduced analyze behaviors anti-vortex bottom sill. The research results indicate that verify accuracy CFD. sill can effectively improve flow pattern reduce rolling behind forebay, enhance axial velocity uniformity at inlet section sump, loss. high zone mainly distributed core top Therefore, shock are main causes square more severe loss compared trapezoidal provide references for setting up hydraulic optimization measures similar stations.

Language: Английский

Citations

3
Energy loss evaluation of a radial inflow turbine for organic Rankine cycle application using hierarchical entropy production method DOI
Zhiqi Wang,

Huya Yang,

Xin Li

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(7)

Published: July 1, 2024

To evaluate the location and main sources of energy loss in radial inflow turbines for organic Rankine cycle application, this study proposed a hierarchical entropy production method, which is superior to traditional pressure drop method. The method includes three levels: local production, split turbine total component production. under design condition different ratios presented. results indicate that high-entropy zone primarily located at stator trailing edge rotor tip clearance. proportion turbulent wall about 77% 20%, respectively. Among components turbine, diffuser highest, accounting 71.9% 13.6% However, have higher volume average generation rate area rate. region mainly outlet zone. When ratio increases from 3 5, efficiency decreases by 13.44%. has significant effect on rotor. This can provide insight into characteristics applications.

Language: Английский

Citations

2
Numerical simulation and mechanistic model study of gas pocket distribution characteristics in a centrifugal impeller DOI

Xiaobin Su,

Qiang Xu, Chenyu Yang

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(11)

Published: Nov. 1, 2024

The formation and extension of the gas pocket in impeller can lead to rapid deterioration or even failure centrifugal pump's two-phase pressurization. It is difficult directly measure characteristic parameters high-speed rotating impeller, such as void fraction, by experimental methods. In this paper, performance pump studied numerical simulation validated experiment. positive pressure gradient at end blade surface main reason why boost high inlet volume fraction (IGVF). As IGVF increases, both length thickness gradually increase. head coefficient has an approximately quadratic relationship with impeller. mechanism model flow established force analysis its downstream single bubble channel. effectively predict position simulation.

Language: Английский

Citations

1
Hydrodynamic Design and Pulsation Evolution in an Axial-Flow Pump Based On Control Mechanism of Flow-Induced Excitation DOI

Kexin Pu,

Xiangsong Liu,

Qipeng Li

et al.

Journal of Fluids Engineering, Journal Year: 2024, Volume and Issue: 147(1)

Published: Aug. 29, 2024

Abstract The physical mechanism, evolution process, and control method on pulsation caused by flow-induced excitation vortex in an axial flow pump are elaborated numerical calculation experiment. mechanism formulation of vibration the unique hydrodynamic design airfoil proposed with three contrast models. According to action law inertial centrifugal force rotor–stator interaction (RSI) region guide vane airfoil, evaluation between transport, turbulent kinetic energy (TKE) structure under transient steady-state internal field is established, which navigates instability intensity determined uneven gradient distribution. distribution characteristics RSI static quantitatively verified Along streamwise direction, loss changes from impact loss, affected wake-jet vortices transforming into intervane vane. In evaluation, form blade frequency fBPF low band. Overall, generation analysis realized based optimal comparison models, provides guidance for optimization reduce consumption cooling system.

Language: Английский

Citations

0
The Spatio‐Temporal Characteristics of Flow Field Inside a Self‐Priming Pump During the Self‐Priming Process DOI Creative Commons
Yuliang Zhang, Jingfu Li, Yan‐Juan Zhao

et al.

Energy Science & Engineering, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 29, 2024

ABSTRACT In this article, a closed‐loop piping system that includes the self‐priming pump is established and calculated. Two operating processes reflecting real situations are accurately calculated by means of UDF. The vortex identification method, entropy production theory, energy gradient method employed to deeply analyze reveal loss characteristics flow stability. results show in oscillating exhaust stage, greatest during stage process. reflux hole, tongue, outlet section volute have larger loss. Within impeller region, mainly concentrated at inlet outlet; distribution area value clearance wear‐ring. addition, instability region left side significantly than rest locations increases considerably with

Language: Английский

Citations

0