Numerical and Experimental Investigation on Unsteady Flow and Hydraulic Radial Force of Low-Head Axial Flow Turbine
Radial force in low-head axial flow turbines (AFTs) is an influential factor in their operational stability. To explore the transient operating behavior of the radial force in low-head AFTs under different blade numbers, transient numeric computations were executed with the shear stress transport (S...
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| Format: | Article |
| Language: | English |
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Isfahan University of Technology
2023-01-01
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| Series: | Journal of Applied Fluid Mechanics |
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| Online Access: | https://www.jafmonline.net/article_2184_5a1e427c1288a314905f0e190cfd721e.pdf |
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| author | Y. Sunsheng I. Enema Ohiemi P. Singh Y. Li A. Ali F. Osman |
| author_facet | Y. Sunsheng I. Enema Ohiemi P. Singh Y. Li A. Ali F. Osman |
| author_sort | Y. Sunsheng |
| collection | DOAJ |
| description | Radial force in low-head axial flow turbines (AFTs) is an influential factor in their operational stability. To explore the transient operating behavior of the radial force in low-head AFTs under different blade numbers, transient numeric computations were executed with the shear stress transport (SST) k-w turbulent model. Turbine performance was numerically computed and compared with results from experiments. Furthermore, the unsteady flow field pulsations were experimentally verified by means of pressure sensors. The radial forces on the runners (z = 2, 3, and 4) were each numerically studied in time, frequency, and joint time–frequency fields. The result reveals that the radial force acting on the runner varies with time, since periodic radial forces reflect the vane number on the stay vanes with minimal runner effect. Moreover, the amplitude of the radial forces is directly proportional to the flow rate. Furthermore, the spectral analysis shows that the radial force frequency is close to the blade passing frequency and also increases radially outward since peak values were recorded in this region. Minimal radial force amplitudes were recorded when z = 3, across all flow conditions, making this configuration suitable for smooth and reliable operation. The unstable pressure and force pulses that affect the noise and vibration produced in the turbine are instigated by the flow exchange that occurs between the guide vane and the runner. In order to optimize turbines for increased operational dependability, the acquired data would be crucial references for noise and vibration analytical investigations. |
| first_indexed | 2024-04-10T17:03:35Z |
| format | Article |
| id | doaj.art-0675b976206d4728979c9186ea769f43 |
| institution | Directory Open Access Journal |
| issn | 1735-3572 1735-3645 |
| language | English |
| last_indexed | 2024-04-10T17:03:35Z |
| publishDate | 2023-01-01 |
| publisher | Isfahan University of Technology |
| record_format | Article |
| series | Journal of Applied Fluid Mechanics |
| spelling | doaj.art-0675b976206d4728979c9186ea769f432023-02-06T07:55:54ZengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35721735-36452023-01-0116483084910.47176/jafm.16.04.15352184Numerical and Experimental Investigation on Unsteady Flow and Hydraulic Radial Force of Low-Head Axial Flow TurbineY. Sunsheng0I. Enema Ohiemi1P. Singh2Y. Li3A. Ali4F. Osman5National Research Centre of Pumps, Jiangsu University, Zhenjiang 212013, ChinaNational Research Centre of Pumps, Jiangsu University, Zhenjiang 212013, China 2. Department of Mechanical Engineering, University of Nigeria, Nsukka 410001, NigeriaCentre for Sustainable Technologies, Indian Institute of Science, CV Raman Road, Bangalore, India, 560012National Research Centre of Pumps, Jiangsu University, Zhenjiang 212013, ChinaNational Research Centre of Pumps, Jiangsu University, Zhenjiang 212013, ChinaSchool of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, ChinaRadial force in low-head axial flow turbines (AFTs) is an influential factor in their operational stability. To explore the transient operating behavior of the radial force in low-head AFTs under different blade numbers, transient numeric computations were executed with the shear stress transport (SST) k-w turbulent model. Turbine performance was numerically computed and compared with results from experiments. Furthermore, the unsteady flow field pulsations were experimentally verified by means of pressure sensors. The radial forces on the runners (z = 2, 3, and 4) were each numerically studied in time, frequency, and joint time–frequency fields. The result reveals that the radial force acting on the runner varies with time, since periodic radial forces reflect the vane number on the stay vanes with minimal runner effect. Moreover, the amplitude of the radial forces is directly proportional to the flow rate. Furthermore, the spectral analysis shows that the radial force frequency is close to the blade passing frequency and also increases radially outward since peak values were recorded in this region. Minimal radial force amplitudes were recorded when z = 3, across all flow conditions, making this configuration suitable for smooth and reliable operation. The unstable pressure and force pulses that affect the noise and vibration produced in the turbine are instigated by the flow exchange that occurs between the guide vane and the runner. In order to optimize turbines for increased operational dependability, the acquired data would be crucial references for noise and vibration analytical investigations.https://www.jafmonline.net/article_2184_5a1e427c1288a314905f0e190cfd721e.pdfaxial flow turbineradial forceblade numberunsteady flow fieldperformancepressure pulsation |
| spellingShingle | Y. Sunsheng I. Enema Ohiemi P. Singh Y. Li A. Ali F. Osman Numerical and Experimental Investigation on Unsteady Flow and Hydraulic Radial Force of Low-Head Axial Flow Turbine Journal of Applied Fluid Mechanics axial flow turbine radial force blade number unsteady flow field performance pressure pulsation |
| title | Numerical and Experimental Investigation on Unsteady Flow and Hydraulic Radial Force of Low-Head Axial Flow Turbine |
| title_full | Numerical and Experimental Investigation on Unsteady Flow and Hydraulic Radial Force of Low-Head Axial Flow Turbine |
| title_fullStr | Numerical and Experimental Investigation on Unsteady Flow and Hydraulic Radial Force of Low-Head Axial Flow Turbine |
| title_full_unstemmed | Numerical and Experimental Investigation on Unsteady Flow and Hydraulic Radial Force of Low-Head Axial Flow Turbine |
| title_short | Numerical and Experimental Investigation on Unsteady Flow and Hydraulic Radial Force of Low-Head Axial Flow Turbine |
| title_sort | numerical and experimental investigation on unsteady flow and hydraulic radial force of low head axial flow turbine |
| topic | axial flow turbine radial force blade number unsteady flow field performance pressure pulsation |
| url | https://www.jafmonline.net/article_2184_5a1e427c1288a314905f0e190cfd721e.pdf |
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