Prediction of dynamic blade loading of the Francis-99 turbine

Nicolle, Jonathan; Cupillard, Samuel

doi:10.1088/1742-6596/579/1/012001

Cited by 16 publications

(19 citation statements)

References 4 publications

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“…Figure 9 shows the near-boundary velocity variation on the pressure and suction sides of a guide vane for the different values of y + . According to author, the boundary layer on the pressure and suction sides of the guide vane was approximately 0.2 and 0.6 mm, respectively [6]. The location of the profile was 90% of chord length from the leading of the guide vane at mid-plane, which is 10.3 mm before the trailing edge.…”

Section: Mesh Scaling Testmentioning

confidence: 98%

“…The calibration of the instruments and sensors was performed for the magnetic flow meter, torque measurement sensors, runner speed measurement sensor, inlet and differential pressure transducers, and miniature pressure sensors. The total uncertainty was obtained by combining the systematic and random uncertainties, as shown in Equation (2), and was calculated to be˘0.15% [5][6][7]:…”

Section: Calibration and Uncertainty Analysismentioning

confidence: 99%

“…The maximum mesh density for the complete turbine generated approximately 48 million nodes [8]. Total nine research groups [6,[9][10][11][12][13][14][15][16] have performed their own mesh scaling test as stated in Table 3, "Mesh scaling test". The simulations were performed after the mesh scaling test.…”

Section: Mesh Creation and Qualitymentioning

confidence: 99%

“…The dimensionless node spacing from the wall was dependent on the type of turbulence model analyzed in the numerical study. For the simulations performed using the SST and/or SAS models, the y + value was maintained as less than one [6]. For the RANS models with the scalable wall function, the average y + value was approximately 300.…”

Section: Mesh Creation and Qualitymentioning

confidence: 99%

“…As summarized in Table 3, some of the research groups performed their own mesh scaling tests before the final simulations. Nicolle and Cupillard [6] created their own geometry and mesh of the Francis turbine. Passages of the distributor and the runner were modeled.…”

Section: Mesh Scaling Testmentioning

confidence: 99%

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Experimental and Numerical Studies of a High-Head Francis Turbine: A Review of the Francis-99 Test Case

2016

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Hydraulic turbines are widely used to meet real-time electricity demands. Computational fluid dynamic (CFD) techniques have played an important role in the design and development of such turbines. The simulation of a complete turbine requires substantial computational resources. A specific approach that is applied to investigate the flow field of one turbine may not work for another turbine. A series of Francis-99 workshops have been planned to discuss and explore the CFD techniques applied within the field of hydropower with application to high-head Francis turbines. The first workshop was held in December 2014 at the Norwegian University of Science and Technology, Norway. The steady-state measurements were conducted on a model Francis turbine. Three operating points, part load, best efficiency point, and high load, were investigated. The complete geometry, meshing, and experimental data concerning the hydraulic efficiency, pressure, and velocity were provided to the academic and industrial research groups. Various researchers have conducted extensive numerical studies on the high-head Francis turbine, and the obtained results were presented during the workshop. This paper discusses the presented numerical results and the important outcome of the extensive numerical studies on the Francis turbine. The use of a wall function assuming equilibrium between the production and dissipation of turbulence is widely used in the simulation of hydraulic turbines. The boundary layer of hydraulic turbines is not fully developed because of the continuously-changing geometry and large pressure gradients. There is a need to develop wall functions that enable the estimation of viscous losses under boundary development for accurate simulations. Improved simulations and results enable reliable estimation of the blade loading. Numerical investigations on leakage flow through the labyrinth seals were conducted. The volumetric efficiency and losses in the seals were determined. The seal leakage losses formulated through analytical techniques are sufficient.

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Section: Mesh Scaling Testmentioning

confidence: 98%