Application of the non-linear harmonic method to study the rotor-stator interaction in Francis-99 test case

Buron, Jean-David; Houde, Sébastien; Lestriez, R; Deschênes, Claire

doi:10.1088/1742-6596/579/1/012013

Cited by 5 publications

(11 citation statements)

References 4 publications

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“…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 mesh sensitivity analysis exhibited numerical errors of 1.7%, 0.6%, and 0.4% for the distributor, runner, and draft tube, respectively. Head losses in the turbine for the three mesh densities at two different grid levels [16]. The three curves represent a mesh sensitivity analysis of the distributor (upper); runner (middle); and diffuser (lower), respectively.…”

Section: Mesh Scaling Testmentioning

confidence: 99%

“…Numerical estimation of hydraulic efficiency are influenced by the boundary conditions, turbulence modelling, combined performance of distributor, runner, and draft tube, interface modeling, and performance of numerical mesh under different Figure 10. Head losses in the turbine for the three mesh densities at two different grid levels [16]. The three curves represent a mesh sensitivity analysis of the distributor (upper); runner (middle); and diffuser (lower), respectively.…”

Section: Quantity Of Interestmentioning

confidence: 99%

“…Two operating conditions are shown: BEP and HL. The simulations were performed using the Spalart-Allmaras turbulence model [16]. A guide vane and a runner passage with a complete draft tube were modeled.…”

Section: Pressurementioning

confidence: 99%

“…A time-domain comparison of the pressure values was conducted. Figures 15 and 16 show time and pressure variations in the vaneless space and the runner at the BEP, respectively [16]. The pressure varying with the runner rotation is shown.…”

Section: Pressurementioning

confidence: 99%

See 4 more Smart Citations

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 Creation and Qualitymentioning

confidence: 99%

Section: Mesh Scaling Testmentioning

confidence: 99%

Section: Quantity Of Interestmentioning

confidence: 99%

Section: Pressurementioning

confidence: 99%

Section: Pressurementioning

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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State of the art in numerical simulation of high head Francis turbines

Trivedi

Cervantes

2016

Renew. Energy Environ. Sustain.

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The Francis-99 test case consists in a high head Francis turbine model, which geometry together with meshes and detailed experimental measurements is freely available at www.francis-99.org. Three workshops were initially planned to exchange experience on numerical investigations of the test case concerning steady state operating conditions, transient operating conditions and fluid structure analysis. The first workshop was held in Trondheim, Norway in December 2014. Some results of the 14 contributions are presented. They are concerned with the influence of the near wall space discretization and turbulence modelling in order to capture hydraulic efficiency, torque, pressure and velocity with a good uncertainty at three operating conditions.

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Numerical Techniques Applied to Hydraulic Turbines: A Perspective Review

Trivedi

Cervantes

Dahlhaug

2016

Applied Mechanics Reviews

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Applications of computational fluid dynamic (CFD) techniques to hydropower have increased rapidly in the last three decades. The majority of the experimental investigations of hydraulic turbines were supported by numerical studies and this has become a standard practice. In the paper, applied numerical techniques and flow modeling approaches to simulate the hydraulic turbines are discussed. Both steady-state and transient operating conditions of the turbines are considered for the review. The steady-state conditions include the best efficiency point (BEP), high load (HL), and part load (PL). The transient conditions include load variation, startup, shutdown, and total load rejection. The performance of the applied numerical models and turbulence modeling with respect to the operating conditions are discussed. The recently developed numerical technique (transient blade row modeling) using the Fourier transformation (FT) method is discussed. This technique allows guide vane and blade passages to be modeled with the pitch ratio other than unity. Numerical modeling and simulation of hydraulic turbines during the transient operating conditions is one of the most challenging tasks because guide vanes' angular movement is time-dependent and mesh should be dynamic/moving. Different approaches applied to simulate the transient conditions and their limitations are discussed. Overall, this review summarizes the role of numerical techniques, advantages, limitations, and upcoming challenges within hydropower.

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Application of the non-linear harmonic method to study the rotor-stator interaction in Francis-99 test case

Cited by 5 publications

References 4 publications

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

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

State of the art in numerical simulation of high head Francis turbines

Numerical Techniques Applied to Hydraulic Turbines: A Perspective Review

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