Analysis of flow characteristics and cavitation in the vanes of a reversible pump-turbine in pump mode

Kang, Wenzhe; Zhou, Lingjiu; Wang, Zhengwei

doi:10.1016/j.est.2023.107690

Cited by 12 publications

(2 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the choice of turbulence model is particularly important in the calculation accuracy of the wall function. At present, from the multiphase flow numerical studies that have been carried out by different scholars, the SST k-w turbulence model has a higher accuracy in multiphase flow calculations [20,21], and the form of vapor cores is more in compliance with the experimental results.…”

Section: Governing Equationsmentioning

confidence: 98%

Analysis of Cavitation-Induced Unsteady Flow Conditions in Francis Turbines under High-Load Conditions

Wang,

Zhou,

et al. 2023

Processes

View full text Add to dashboard Cite

Hydraulic vibrations in Francis turbines caused by cavitation profoundly impact the overall hydraulic performance and operational stability. Therefore, to investigate the influence of cavitation phenomena under high-load conditions, a three-dimensional unsteady numerical simulation is carried out for a Francis turbine with different head operating conditions, which is combined with the SST k-w turbulence model and two-phase flow cavitation model to capture the evolution of cavitation under high-load conditions. Additionally, utilizing entropy production theory, the hydraulic losses of the Francis turbine during cavitation development are assessed. Contrary to the pressure-drop method, the entropy production theory can quantitatively reflect the characteristics of the local hydraulic loss distribution, with a calculated error coefficient τ not exceeding 2%. The specific findings include: the primary sources of energy loss inside the turbine are the airfoil cavitation and cavitation vortex rope, constituting 26% and 71% of the total hydraulic losses, respectively. According to the comparison with model tests, the vapor volume fraction (VVF) inside the draft tube fluctuates periodically under high-load conditions, causing low-frequency pressure pulsation in the turbine’s power, flow rate, and other external characteristic parameters at 0.37 Hz, and the runner radial force fluctuates at a frequency of 1.85 Hz.

show abstract

Section: Governing Equationsmentioning

confidence: 98%

Analysis of Cavitation-Induced Unsteady Flow Conditions in Francis Turbines under High-Load Conditions

Wang,

Zhou,

et al. 2023

Processes

View full text Add to dashboard Cite

show abstract

“…However, before the conditions reach the "critical cavitation" conditions, in the runner, the actual extent of the cavitation is already quite serious. In reversible pump-turbines, the cavitation coefficient in pump-mode is much greater that in turbine mode [1][2][3]. This means that a pump-turbine working as a pump is more prone to cavitation.…”

Section: Introductionmentioning

confidence: 99%

A bionic anti-cavitation leading edge for pump-turbine

Fang,

Zhang,

Tao

et al. 2024

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Cavitation is one of the most important technical indicators for assessing reversible pump-turbines. This article describes an anti-cavitation leading edge based on a bionic shape to reduce cavitation. The shape is based on 6 typical fish-like streamlined profiles analyzed in CFD simulations. The flow fields around the profiles were analyzed for different angles of attack to identify the one with the least flow separation and a flat pressure drop. A bionic runner was then built to give an anti-cavitation leading edge. Three-dimensional CFD simulations show that the anti-cavitation leading edge effectively inhibits local flow separation and reduce the pressure drop. Moreover, cavitation tests show that the bionic runner reduces the cavitation inception coefficients. Thus, this design reduces the number of cavitation bubbles and improves the cavitation performance. These results will improve safety and reduce costs and provide a reference for similar hydraulic machinery experiencing.

show abstract

Quantification of abnormal characteristics and flow-patterns identification in pumped storage system

Chen,

Zhao,

et al. 2024

Nonlinear Dyn

View full text Add to dashboard Cite

Analysis of flow characteristics and cavitation in the vanes of a reversible pump-turbine in pump mode

Cited by 12 publications

References 31 publications

Analysis of Cavitation-Induced Unsteady Flow Conditions in Francis Turbines under High-Load Conditions

Analysis of Cavitation-Induced Unsteady Flow Conditions in Francis Turbines under High-Load Conditions

A bionic anti-cavitation leading edge for pump-turbine

Quantification of abnormal characteristics and flow-patterns identification in pumped storage system

Contact Info

Product

Resources

About