Study on the Accuracy of RANS Modelling of the Turbulent Flow Developed in a Kaplan Turbine Operated at BEP. Part 1 - Velocity Field
This paper investigates the accuracy of Reynolds-averaged Navier-Stokes (RANS) turbulence modelling applied to complex industrial applications. In the context of the increasing instability of the energy market, hydropower plants are frequently working at off-design parameters. Such operation conditi...
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| Format: | Article |
| Language: | English |
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Isfahan University of Technology
2019-01-01
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| Series: | Journal of Applied Fluid Mechanics |
| Subjects: | |
| Online Access: | http://jafmonline.net/JournalArchive/download?file_ID=49506&issue_ID=1002 |
| _version_ | 1811315661966671872 |
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| author | R. G. Iovănel D. M. Bucur M. J. Cervantes |
| author_facet | R. G. Iovănel D. M. Bucur M. J. Cervantes |
| author_sort | R. G. Iovănel |
| collection | DOAJ |
| description | This paper investigates the accuracy of Reynolds-averaged Navier-Stokes (RANS) turbulence modelling applied to complex industrial applications. In the context of the increasing instability of the energy market, hydropower plants are frequently working at off-design parameters. Such operation conditions have a strong impact on the efficiency and life span of hydraulic turbines. Therefore, research is currently focused on improving the design and increasing the operating range of the turbines. Numerical simulations represent an accessible and cost efficient alternative to model testing. The presented test case is the Porjus U9 Kaplan turbine model operated at best efficiency point (BEP). Both steady and unsteady numerical simulations are carried out using different turbulence models: k-epsilon, RNG k-epsilon and k-omega Shear Stress Transport (SST). The curvature correction method applied to the SST turbulence model is also evaluated showing nearly no sensitivity to the different values of the production correction coefficient Cscale. The simulations are validated against measurements performed in the turbine runner and draft tube. The numerical results are in good agreement with the experimental time-dependent velocity profiles. The advantages and limitations of RANS modelling are discussed. The most accurate results were provided by the simulations using the k-epsilon and the SST-CC turbulence models but very small differences were obtained between the different tested models. The precision of the numerical simulations decreased towards the outlet of the computational domain. In a companion paper, the pressure profiles obtained numerically are investigated and compared to experimental data. |
| first_indexed | 2024-04-13T11:34:43Z |
| format | Article |
| id | doaj.art-fc433cdc264847a48a4dc03fb55dca5d |
| institution | Directory Open Access Journal |
| issn | 1735-3572 |
| language | English |
| last_indexed | 2024-04-13T11:34:43Z |
| publishDate | 2019-01-01 |
| publisher | Isfahan University of Technology |
| record_format | Article |
| series | Journal of Applied Fluid Mechanics |
| spelling | doaj.art-fc433cdc264847a48a4dc03fb55dca5d2022-12-22T02:48:29ZengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722019-01-0112514491461.Study on the Accuracy of RANS Modelling of the Turbulent Flow Developed in a Kaplan Turbine Operated at BEP. Part 1 - Velocity FieldR. G. Iovănel0D. M. Bucur1M. J. Cervantes2University Politehnica of Bucharest, 060042, RomaniaUniversity Politehnica of Bucharest, 060042, RomaniaLuleå University of Technology and Norwegian University of Science and Technology, TrondheimThis paper investigates the accuracy of Reynolds-averaged Navier-Stokes (RANS) turbulence modelling applied to complex industrial applications. In the context of the increasing instability of the energy market, hydropower plants are frequently working at off-design parameters. Such operation conditions have a strong impact on the efficiency and life span of hydraulic turbines. Therefore, research is currently focused on improving the design and increasing the operating range of the turbines. Numerical simulations represent an accessible and cost efficient alternative to model testing. The presented test case is the Porjus U9 Kaplan turbine model operated at best efficiency point (BEP). Both steady and unsteady numerical simulations are carried out using different turbulence models: k-epsilon, RNG k-epsilon and k-omega Shear Stress Transport (SST). The curvature correction method applied to the SST turbulence model is also evaluated showing nearly no sensitivity to the different values of the production correction coefficient Cscale. The simulations are validated against measurements performed in the turbine runner and draft tube. The numerical results are in good agreement with the experimental time-dependent velocity profiles. The advantages and limitations of RANS modelling are discussed. The most accurate results were provided by the simulations using the k-epsilon and the SST-CC turbulence models but very small differences were obtained between the different tested models. The precision of the numerical simulations decreased towards the outlet of the computational domain. In a companion paper, the pressure profiles obtained numerically are investigated and compared to experimental data.http://jafmonline.net/JournalArchive/download?file_ID=49506&issue_ID=1002Numerical simulation; Turbulence modelling; Hydropower; Kaplan turbine; Experimental validation. |
| spellingShingle | R. G. Iovănel D. M. Bucur M. J. Cervantes Study on the Accuracy of RANS Modelling of the Turbulent Flow Developed in a Kaplan Turbine Operated at BEP. Part 1 - Velocity Field Journal of Applied Fluid Mechanics Numerical simulation; Turbulence modelling; Hydropower; Kaplan turbine; Experimental validation. |
| title | Study on the Accuracy of RANS Modelling of the Turbulent Flow Developed in a Kaplan Turbine Operated at BEP. Part 1 - Velocity Field |
| title_full | Study on the Accuracy of RANS Modelling of the Turbulent Flow Developed in a Kaplan Turbine Operated at BEP. Part 1 - Velocity Field |
| title_fullStr | Study on the Accuracy of RANS Modelling of the Turbulent Flow Developed in a Kaplan Turbine Operated at BEP. Part 1 - Velocity Field |
| title_full_unstemmed | Study on the Accuracy of RANS Modelling of the Turbulent Flow Developed in a Kaplan Turbine Operated at BEP. Part 1 - Velocity Field |
| title_short | Study on the Accuracy of RANS Modelling of the Turbulent Flow Developed in a Kaplan Turbine Operated at BEP. Part 1 - Velocity Field |
| title_sort | study on the accuracy of rans modelling of the turbulent flow developed in a kaplan turbine operated at bep part 1 velocity field |
| topic | Numerical simulation; Turbulence modelling; Hydropower; Kaplan turbine; Experimental validation. |
| url | http://jafmonline.net/JournalArchive/download?file_ID=49506&issue_ID=1002 |
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