Wicket gate trailing-edge blowing: A method for improving off-design hydroturbine performance by adjusting the runner inlet swirl angle

Lewis, B.; Cimbala, John M.; Wouden, Alex

doi:10.1088/1755-1315/22/1/012021

Cited by 4 publications

(3 citation statements)

References 7 publications

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“…Sabri Deniz et al [17,18] conducted both experimental and numerical investigations to assess the influence of various injection parameters by employing flow control techniques involving water injection in the vaneless space and guide vanes near the leading edge. Lewis [19] demonstrated the method of adding water jets to the trailing edge of the guide vanes for improving the Francis hydroturbine performance during off-design operation by adjusting the runner inlet swirl angle. Subodh Khullar et al [20] numerically analyzed water jet injection in the draft tube of a Francis turbine under three different partial load conditions.…”

Section: Introductionmentioning

confidence: 99%

A Study and Optimization of the Unsteady Flow Characteristics in the Last Stage Impeller of a Small-Scale Multi-Stage Hydraulic Turbine

Yang,

Peng,

et al. 2023

Energies

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The demand for small-size multi-stage hydraulic turbines is experiencing rapid growth due to the ongoing efforts towards energy conservation and emission reduction. On account of their compact structural design, these turbines feature a more intricate internal flow configuration, rendering them prone to the creation of low-pressure zones, resulting in vapor–liquid two-phase flow, accompanied by the development of intense vibrations and noise, thereby adversely affecting the safety and stability of turbine operations. Concurrently, an innovative method for analyzing flow fields has been formulated combined with two-dimensional frequency domain visualization technology and proper orthogonal decomposition, serving to establish a diagnostic and optimization framework for the unsteady flow structures within rotating machinery by considering the features related to frequency distribution, spatial distribution, and energy contributions. It was found that there are two main unsteady flow structures which are the areas with high risks of vaporization under this study condition. According to the flow characteristics of the analysis, an optimization scheme was proposed to improve the two-phase flow problem in the secondary impeller, and the preliminary results were satisfactory.

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Section: Introductionmentioning

confidence: 99%

A Study and Optimization of the Unsteady Flow Characteristics in the Last Stage Impeller of a Small-Scale Multi-Stage Hydraulic Turbine

Yang,

Peng,

et al. 2023

Energies

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“…Lewis [29] demonstrated the method of adding water jets to the trailing edge of the guide vanes for improving the Francis hydroturbine performance during off-design operation by adjusting the runner inlet swirl angle. When it is properly tuned, altering the flow angle results in a significant improvement in turbine efficiency during off-design operation.…”

Section: Introductionmentioning

confidence: 99%

The Suppression of Hump Instability inside a Pump Turbine in Pump Mode Using Water Injection Control

et al. 2023

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The occurrence of hump instability in pump mode within a pump turbine poses a significant challenge to the safe and stable operation of Pumped Storage Power Plants (PSPP). To achieve more precise numerical simulations, this paper establishes a weakly compressible model of water based on the Tait equation. Using this model, it is discovered that the onset of hump instability is closely linked to an increase in hydraulic losses induced by stalled rotation within the diffuser. Then, a flow control approach employing water injection into the guide vanes of a pump turbine is proposed in order to suppress flow instabilities and optimize the hump region. The findings reveal that the water injection approach can mitigate hydraulic losses, suppress unstable structures, and diminish the pulsation amplitude within the diffuser, ultimately delaying the emergence of the hump region to lower flow mass conditions. This study is helpful in widening the range of the safe and stable operation of pump turbines in pump mode.

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“…Hydraulic design of Three Gorges right bank hydraulic turbine is presented by Shi; 10 the method for better hydraulic stability, excellent cavitation behavior, and good performance characteristics at off-design operating conditions is clarified. Lewis et al 11 put forward a method to improve hydraulic performance at off-design operating conditions by injecting water through slots at the trailing edges of the wicket gates.…”

Section: Introductionmentioning

confidence: 99%

Characteristic analysis of the efficiency hill chart of Francis turbine for different water heads

Guo

Wang

Sun

et al. 2017

Advances in Mechanical Engineering

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According to several model test results of Francis turbines, complete model efficiency hill charts were constructed. The formation and inevitability of diversified hydraulic phenomena on model efficiency hill chart for typical head range were analyzed and the difference is compared, as well as characteristics and commonness toward the curves are discussed and summarized. Furthermore, hydraulic performance and geometric features are presented by particularly analyzing the efficiency hill charts. The inherent characteristics of Francis turbine is expressed by all kinds of curves on the model efficiency hill charts, and these curves can be adjusted and moved in a small range but cannot be removed out. Due to wide range of unit speed in terms of medium-low-head hydraulic turbines, incipient cavitation curve on suction side can be observed and it is positioned close to the operation zone; however, it fails to be visualized for the high-head turbine. The blade channel vortex curves are in the vicinity of optimum region for low-head hydraulic turbines, while high-head shows reverse trend. The interaction between zero incidence angle and zero circulation curve has a significant influence on isoefficiency circles. All comparisons and analyses could provide hydraulic design basis and retrofit references.

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Wicket gate trailing-edge blowing: A method for improving off-design hydroturbine performance by adjusting the runner inlet swirl angle

Cited by 4 publications

References 7 publications

A Study and Optimization of the Unsteady Flow Characteristics in the Last Stage Impeller of a Small-Scale Multi-Stage Hydraulic Turbine

A Study and Optimization of the Unsteady Flow Characteristics in the Last Stage Impeller of a Small-Scale Multi-Stage Hydraulic Turbine

The Suppression of Hump Instability inside a Pump Turbine in Pump Mode Using Water Injection Control

Characteristic analysis of the efficiency hill chart of Francis turbine for different water heads

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