Wind Tunnel Experiments on Interaction between Two Closely Spaced Vertical-Axis Wind Turbines in Side-by-Side Arrangement
This study aimed to determine the optimal rotor spacing of two vertical-axis wind turbines, which are simulated by miniature models arranged side-by-side with a relatively low aspect ratio. Wind tunnel experiments with a pair of 3-D printed model rotors were conducted at a uniform velocity. A series...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-11-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/14/23/7874 |
| _version_ | 1797507844367450112 |
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| author | Yoshifumi Jodai Yutaka Hara |
| author_facet | Yoshifumi Jodai Yutaka Hara |
| author_sort | Yoshifumi Jodai |
| collection | DOAJ |
| description | This study aimed to determine the optimal rotor spacing of two vertical-axis wind turbines, which are simulated by miniature models arranged side-by-side with a relatively low aspect ratio. Wind tunnel experiments with a pair of 3-D printed model rotors were conducted at a uniform velocity. A series of experiments were conducted involving both incremental adjustments to the rotor gaps, <i>g</i>, and the rotational direction of each rotor. Increases in the power and the related flow patterns were observed in all three arrangements: Co-Rotating (CO), Counter-Up (CU), and Counter-Down (CD). The maximum phase-synchronized rotational speed occurs at the narrowest gap in the CD arrangement. Meanwhile, local maxima arise in the CO and CU arrangements at <i>g</i>/<i>D</i> < 1, where <i>D</i> is the rotor diameter. From an engineering perspective, the optimal rotor spacing is <i>g</i>/<i>D</i> = 0.2 with the CO arrangement, using the same two rotors rotating in the same direction. Based on flow visualization using a smoke-wire method at a narrower gap opening of 0.2<i>D</i>, the wake width in the case of the CU arrangement was remarkably narrower than those obtained in the CO and CD arrangements. In the CU arrangement, a movement towards the center of the rotor pair of the nominal front-stagnation point of each rotor was confirmed via flow visualization. This finding explains a reduction tendency in the rotational speed of the rotors via a reduction in the lift in the CU arrangement. |
| first_indexed | 2024-03-10T04:55:07Z |
| format | Article |
| id | doaj.art-461575f87bad47208ad56e44a084384f |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-10T04:55:07Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-461575f87bad47208ad56e44a084384f2023-11-23T02:19:08ZengMDPI AGEnergies1996-10732021-11-011423787410.3390/en14237874Wind Tunnel Experiments on Interaction between Two Closely Spaced Vertical-Axis Wind Turbines in Side-by-Side ArrangementYoshifumi Jodai0Yutaka Hara1Department of Mechanical Engineering, Kagawa National Institute of Technology (KOSEN), Kagawa College, 355 Chokushi, Takamatsu 761-8058, JapanFaculty of Engineering, Tottori University, 4-101 Koyama-Minami, Tottori 680-8552, JapanThis study aimed to determine the optimal rotor spacing of two vertical-axis wind turbines, which are simulated by miniature models arranged side-by-side with a relatively low aspect ratio. Wind tunnel experiments with a pair of 3-D printed model rotors were conducted at a uniform velocity. A series of experiments were conducted involving both incremental adjustments to the rotor gaps, <i>g</i>, and the rotational direction of each rotor. Increases in the power and the related flow patterns were observed in all three arrangements: Co-Rotating (CO), Counter-Up (CU), and Counter-Down (CD). The maximum phase-synchronized rotational speed occurs at the narrowest gap in the CD arrangement. Meanwhile, local maxima arise in the CO and CU arrangements at <i>g</i>/<i>D</i> < 1, where <i>D</i> is the rotor diameter. From an engineering perspective, the optimal rotor spacing is <i>g</i>/<i>D</i> = 0.2 with the CO arrangement, using the same two rotors rotating in the same direction. Based on flow visualization using a smoke-wire method at a narrower gap opening of 0.2<i>D</i>, the wake width in the case of the CU arrangement was remarkably narrower than those obtained in the CO and CD arrangements. In the CU arrangement, a movement towards the center of the rotor pair of the nominal front-stagnation point of each rotor was confirmed via flow visualization. This finding explains a reduction tendency in the rotational speed of the rotors via a reduction in the lift in the CU arrangement.https://www.mdpi.com/1996-1073/14/23/7874two vertical-axis wind turbineswind tunnel experimentwakeflow visualizationphase-synchronized rotationpower coefficient |
| spellingShingle | Yoshifumi Jodai Yutaka Hara Wind Tunnel Experiments on Interaction between Two Closely Spaced Vertical-Axis Wind Turbines in Side-by-Side Arrangement Energies two vertical-axis wind turbines wind tunnel experiment wake flow visualization phase-synchronized rotation power coefficient |
| title | Wind Tunnel Experiments on Interaction between Two Closely Spaced Vertical-Axis Wind Turbines in Side-by-Side Arrangement |
| title_full | Wind Tunnel Experiments on Interaction between Two Closely Spaced Vertical-Axis Wind Turbines in Side-by-Side Arrangement |
| title_fullStr | Wind Tunnel Experiments on Interaction between Two Closely Spaced Vertical-Axis Wind Turbines in Side-by-Side Arrangement |
| title_full_unstemmed | Wind Tunnel Experiments on Interaction between Two Closely Spaced Vertical-Axis Wind Turbines in Side-by-Side Arrangement |
| title_short | Wind Tunnel Experiments on Interaction between Two Closely Spaced Vertical-Axis Wind Turbines in Side-by-Side Arrangement |
| title_sort | wind tunnel experiments on interaction between two closely spaced vertical axis wind turbines in side by side arrangement |
| topic | two vertical-axis wind turbines wind tunnel experiment wake flow visualization phase-synchronized rotation power coefficient |
| url | https://www.mdpi.com/1996-1073/14/23/7874 |
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