Particle Image Velocimetry Test for the Inter-Blade Vortex in a Francis Turbine

Xu, Lianchen; Jin, Xiaohui; Li, Zhen; Deng, Wanquan; Liu, Demin; Liu, Xiaobing

doi:10.3390/pr9111968

Cited by 12 publications

(4 citation statements)

References 18 publications

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“…), PIV has the advantages of high accuracy, large imaging area, easy installation, and strong anti-interference ability (Li et al, 2021a) Yan et al, (2019 used the PIV test method to study the flow pattern inside the runner of a Francis pump turbine, and determined the influence of the impingement angle of the runner blade and the GVO on the flow pattern. Tang et al (2020), Xu et al (2021) used the PIV test method to study the inter-blade vortex of a Francis turbine and obtained the initiation and development of the inter-blade vortex. The author also used the PIV test method to test the pump turbine under four-quadrant working conditions.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Computational Fluid Dynamics Study of the Flow Field of a Model Pump Turbine

Deng¹,

Xu²,

Li³

et al. 2022

Front. Energy Res.

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The pumped storage unit has a hump area and S characteristics during operation. The operating conditions of the unit are complex, and it is necessary to switch between working conditions. The unit frequently crosses the hump area and the S characteristic area, thus hindering the unit to connect to the grid. Severe vibration affects the safe and stable operation of a power station. With the joint efforts of the industry, the impact of the hump and S-shaped problems on project commissioning has been fundamentally resolved, but the mechanism of inducing hump and S-shaped problems has not yet been well established. Therefore, in this study, the particle image velocity measurement method based on a full-characteristic test was adopted. According to the operating characteristics of the unit, 32 operating points with four guide-vane opening degrees were selected to test the flow pattern in the vaneless space. After subtracting the average flow velocity, the vortex image of the leafless area was obtained, which provided a reference for the design of the runner of the water pump turbine.

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Section: Introductionmentioning

confidence: 99%

Experimental and Computational Fluid Dynamics Study of the Flow Field of a Model Pump Turbine

Deng¹,

Xu²,

Li³

et al. 2022

Front. Energy Res.

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“…Two main techniques commonly used in hydraulic machines are particle image velocimetry (PIV) and LDV. PIV is well suited for studying the evolution of flow structures [20,21], while LDV offers higher accuracy in local velocity measurements [22,23]. When the velocity of a point needs to be measured in pump turbines, the LDV technique has become the preferred experimental approach due to its superior accuracy.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the Energy Loss Mechanism of Pump-Turbines with Splitter Blades under Different Characteristic Heads

Gui,

Xu,

et al. 2023

Water

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The operating efficiency of high-head pump turbines is closely related to the internal hydraulic losses within the system. Conventional methods for calculating hydraulic losses based on pressure differences often lack detailed information on their distribution and specific sources. Additionally, the presence of splitter blades further complicates the hydraulic loss characteristics, necessitating further study. In this study, Reynolds-averaged Navier–Stokes (RANS) simulations were employed to analyze the performance of a pump turbine with splitter blades at three different head conditions and a guide vane opening (GVO) of 10°. The numerical simulations were validated by experimental tests using laser doppler velocimetry (LDV). Quantitative analysis of flow components and hydraulic losses was conducted using entropy production theory in combination with an examination of flow field distributions to identify the origins and features of hydraulic losses. The results indicate that higher heads are associated with lower growth rates of total hydraulic losses. In particular, the significant velocity gradients at the trailing edge of the splitter blades contribute to higher hydraulic losses. Furthermore, the hydraulic losses in the runner (RN) region are predominantly influenced by velocity gradients and not by vortices, with the flow conditions in the RN region impacting the hydraulic losses in the draft tube (DT).

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“…Yan et al [28] used the PIV test method to study the flow regime inside the runner of a Francis pump-turbine and determined the influence of the impingement angle of the runner blade and the GVO on the flow regime. Tang [29] and Xu [30] used the PIV test method to study the inter-blade vortex of a Francis turbine and obtained the initiation and development of the inter-blade vortex. The authors also used the PIV test method to test the pump-turbine under four-quadrant working conditions.…”

Section: Introductionmentioning

confidence: 99%

Stability Analysis of Vaneless Space in High-Head Pump-Turbine under Turbine Mode: Computational Fluid Dynamics Simulation and Particle Imaging Velocimetry Measurement

Deng

Zhen

et al. 2022

Machines

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When the Francis-type reversible pump-turbine runs under partial load, the pressure pulsation amplitude and frequency in vaneless space are high, posing a serious threat to the stability of unit operation. Water presents weak compressibility in a high-head pump-turbine, thereby affecting the amplitude–frequency characteristics of pressure pulsation. This study used numerical simulations in a model and prototype pump-turbine and particle image velocimetry (PIV) in a model pump-turbine to examine the internal flow field and pressure pulsation characteristics and determine the effect of the flow in the vaneless space on the amplitude–frequency characteristics of the pressure pulsation. The pressure pulsation amplitude–frequency characteristics were verified through prototype tests. The effects of the weak compressibility of the water on the propagation law of pressure pulsation throughout the flow passage of the prototype and model pump-turbine were roughly similar but exhibited certain differences. Considering the weak compressibility of water, the pressure pulsation fluctuations in each flow passage of the prototype and model pump-turbine exhibit varying degrees of improvement, which is more obvious at the prototype scale. Therefore, the pressure wave disturbance caused by the weak compressibility of the water has different effects on the prototype scale and model scale of the high-head Francis pump-turbine.

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Particle Image Velocimetry Test for the Inter-Blade Vortex in a Francis Turbine

Cited by 12 publications

References 18 publications

Experimental and Computational Fluid Dynamics Study of the Flow Field of a Model Pump Turbine

Experimental and Computational Fluid Dynamics Study of the Flow Field of a Model Pump Turbine

Analysis of the Energy Loss Mechanism of Pump-Turbines with Splitter Blades under Different Characteristic Heads

Stability Analysis of Vaneless Space in High-Head Pump-Turbine under Turbine Mode: Computational Fluid Dynamics Simulation and Particle Imaging Velocimetry Measurement

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