On the Flow Instabilities and Turbulent Kinetic Energy of Large-Scale Francis Hydroturbine Model at Low Flow Rate Conditions
This paper is to make a better understanding of the flow instabilities and turbulent kinetic energy (TKE) features in a large-scale Francis hydroturbine model. The flow instability with aspect of pressure oscillation and pressure-velocity correlation was investigated using large eddy simulation (LES...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
SAGE Publishing
2014-07-01
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| Series: | Advances in Mechanical Engineering |
| Online Access: | https://doi.org/10.1155/2014/786891 |
| _version_ | 1819150418066800640 |
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| author | Wen-Tao Su Xiao-Bin Li Feng-Chen Li Xian-Zhu Wei Jin-Tao Liu Yu-Lin Wu |
| author_facet | Wen-Tao Su Xiao-Bin Li Feng-Chen Li Xian-Zhu Wei Jin-Tao Liu Yu-Lin Wu |
| author_sort | Wen-Tao Su |
| collection | DOAJ |
| description | This paper is to make a better understanding of the flow instabilities and turbulent kinetic energy (TKE) features in a large-scale Francis hydroturbine model. The flow instability with aspect of pressure oscillation and pressure-velocity correlation was investigated using large eddy simulation (LES) method along with two-phase cavitation model. The numerical simulation procedures were validated by the existing experimental result, and further the TKE evolution was analyzed in a curvilinear coordinates. By monitoring the fluctuating pressure and velocities in the vanes’ wake region, the local pressure and velocity variations were proven to have a phase difference approaching π/2, with a reasonable cross-correlation coefficient. Also the simultaneous evolution of pressure fluctuations at the opposite locations possessed a clear phase difference of π, indicating the stresses variations on the runner induced by pressure oscillation were in an odd number of nodal diameter. Considering the TKE generation, the streamwise velocity component u s ′ 2 contributed the most to the TKE, and thus the normal stress production term and shear stress production term imparted more instability to the flow than other production terms. |
| first_indexed | 2024-12-22T14:17:11Z |
| format | Article |
| id | doaj.art-cfb0959142e143c8bb11e43e2b27ecc9 |
| institution | Directory Open Access Journal |
| issn | 1687-8132 |
| language | English |
| last_indexed | 2024-12-22T14:17:11Z |
| publishDate | 2014-07-01 |
| publisher | SAGE Publishing |
| record_format | Article |
| series | Advances in Mechanical Engineering |
| spelling | doaj.art-cfb0959142e143c8bb11e43e2b27ecc92022-12-21T18:23:04ZengSAGE PublishingAdvances in Mechanical Engineering1687-81322014-07-01610.1155/2014/78689110.1155_2014/786891On the Flow Instabilities and Turbulent Kinetic Energy of Large-Scale Francis Hydroturbine Model at Low Flow Rate ConditionsWen-Tao Su0Xiao-Bin Li1Feng-Chen Li2Xian-Zhu Wei3Jin-Tao Liu4Yu-Lin Wu5 State Key Laboratory of Hydro-Power Equipment, Harbin Institute of Large Electric Machinery, Harbin 150040, China School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China State Key Laboratory of Hydro-Power Equipment, Harbin Institute of Large Electric Machinery, Harbin 150040, China Beijing Institute of Control Engineering, China Aerospace Science and Technology Corporation, Beijing 100190, China State Key Laboratory of Hydro Science and Engineering, Tsinghua University, Beijing 100084, ChinaThis paper is to make a better understanding of the flow instabilities and turbulent kinetic energy (TKE) features in a large-scale Francis hydroturbine model. The flow instability with aspect of pressure oscillation and pressure-velocity correlation was investigated using large eddy simulation (LES) method along with two-phase cavitation model. The numerical simulation procedures were validated by the existing experimental result, and further the TKE evolution was analyzed in a curvilinear coordinates. By monitoring the fluctuating pressure and velocities in the vanes’ wake region, the local pressure and velocity variations were proven to have a phase difference approaching π/2, with a reasonable cross-correlation coefficient. Also the simultaneous evolution of pressure fluctuations at the opposite locations possessed a clear phase difference of π, indicating the stresses variations on the runner induced by pressure oscillation were in an odd number of nodal diameter. Considering the TKE generation, the streamwise velocity component u s ′ 2 contributed the most to the TKE, and thus the normal stress production term and shear stress production term imparted more instability to the flow than other production terms.https://doi.org/10.1155/2014/786891 |
| spellingShingle | Wen-Tao Su Xiao-Bin Li Feng-Chen Li Xian-Zhu Wei Jin-Tao Liu Yu-Lin Wu On the Flow Instabilities and Turbulent Kinetic Energy of Large-Scale Francis Hydroturbine Model at Low Flow Rate Conditions Advances in Mechanical Engineering |
| title | On the Flow Instabilities and Turbulent Kinetic Energy of Large-Scale Francis Hydroturbine Model at Low Flow Rate Conditions |
| title_full | On the Flow Instabilities and Turbulent Kinetic Energy of Large-Scale Francis Hydroturbine Model at Low Flow Rate Conditions |
| title_fullStr | On the Flow Instabilities and Turbulent Kinetic Energy of Large-Scale Francis Hydroturbine Model at Low Flow Rate Conditions |
| title_full_unstemmed | On the Flow Instabilities and Turbulent Kinetic Energy of Large-Scale Francis Hydroturbine Model at Low Flow Rate Conditions |
| title_short | On the Flow Instabilities and Turbulent Kinetic Energy of Large-Scale Francis Hydroturbine Model at Low Flow Rate Conditions |
| title_sort | on the flow instabilities and turbulent kinetic energy of large scale francis hydroturbine model at low flow rate conditions |
| url | https://doi.org/10.1155/2014/786891 |
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