Effects of Gurney Flaps on the Performance of a Horizontal Axis Ocean Current Turbine
Gurney flaps can enhance the hydrodynamic efficiency of airfoils, and they are currently used in several applications, including racing cars and wind turbines. However, there is a lack of studies in the literature on the application of Gurney flaps on the Horizontal Axis Ocean Current Turbine (HAOCT...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-11-01
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| Series: | Journal of Marine Science and Engineering |
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| Online Access: | https://www.mdpi.com/2077-1312/11/11/2188 |
| _version_ | 1797458794803888128 |
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| author | Zhaoyong Mao Tianqi Zhang Guangyong Yang Wenlong Tian |
| author_facet | Zhaoyong Mao Tianqi Zhang Guangyong Yang Wenlong Tian |
| author_sort | Zhaoyong Mao |
| collection | DOAJ |
| description | Gurney flaps can enhance the hydrodynamic efficiency of airfoils, and they are currently used in several applications, including racing cars and wind turbines. However, there is a lack of studies in the literature on the application of Gurney flaps on the Horizontal Axis Ocean Current Turbine (HAOCT). The influence of Gurney flaps on the hydrodynamic efficiency of the HAOCT is evaluated through numerical analysis. The effect of the Gurney flaps on the turbine is evaluated after the validation of the utilized numerical method is completed using the wind tunnel experimental data of the two-dimensional NACA 63415 airfoil and the water tunnel experimental data of the NACA 638xx series rotor on the clean blade. By calculating the velocity and pressure fields of the 2D airfoil by CFD, it was possible to analyze the lift improvement with the addition of the Gurney flaps by evaluating the pressure difference between the pressure surface and the negative pressure surface, and the drag improvement was due to the Gurney flaps obstructing the chordal flow of the fluid in the wake. For the 2D NACA-63415 airfoil, the drag coefficient increases with the increase in the head angle, while the lift coefficient increases and then decreases. The flap height divided by the local chord length of the Gurney flaps is 0.01, and the lift-to-drag ratio is the highest when the head angle is 4°. For the NACA-638xx turbine, the addition of Gurney flaps significantly increases the axial thrust coefficient. At lower tip speed ratios, the effect of the Gurney flaps on the rotor’s power coefficient is limited, with the greatest increase in the power coefficient at a tip speed ratio of 6 and a decrease in the power coefficient increase as the tip speed ratio increases. Increasing the height of the Gurney flaps can increase the peak power coefficient, but the power performance decreases at high tip speed ratios. The Gurney flaps distributed at the root of the rotor have less effect on the power performance. A 0.4 local radius spread of the Gurney flaps increases the peak turbine power coefficient by only 0.34%, while full-length Gurney flaps can increase the peaked blade power coefficient by 10.68%, indicating that Gurney flaps can be used to design a new HAOCT. |
| first_indexed | 2024-03-09T16:42:20Z |
| format | Article |
| id | doaj.art-a38aeda347724f09a25f813e79525325 |
| institution | Directory Open Access Journal |
| issn | 2077-1312 |
| language | English |
| last_indexed | 2024-03-09T16:42:20Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Marine Science and Engineering |
| spelling | doaj.art-a38aeda347724f09a25f813e795253252023-11-24T14:50:49ZengMDPI AGJournal of Marine Science and Engineering2077-13122023-11-011111218810.3390/jmse11112188Effects of Gurney Flaps on the Performance of a Horizontal Axis Ocean Current TurbineZhaoyong Mao0Tianqi Zhang1Guangyong Yang2Wenlong Tian3School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an 710072, ChinaSchool of Marine Science and Technology, Northwestern Polytechnical University, Xi’an 710072, ChinaUnmanned System Research Institute, Northwestern Polytechnical University, Xi’an 710072, ChinaSchool of Marine Science and Technology, Northwestern Polytechnical University, Xi’an 710072, ChinaGurney flaps can enhance the hydrodynamic efficiency of airfoils, and they are currently used in several applications, including racing cars and wind turbines. However, there is a lack of studies in the literature on the application of Gurney flaps on the Horizontal Axis Ocean Current Turbine (HAOCT). The influence of Gurney flaps on the hydrodynamic efficiency of the HAOCT is evaluated through numerical analysis. The effect of the Gurney flaps on the turbine is evaluated after the validation of the utilized numerical method is completed using the wind tunnel experimental data of the two-dimensional NACA 63415 airfoil and the water tunnel experimental data of the NACA 638xx series rotor on the clean blade. By calculating the velocity and pressure fields of the 2D airfoil by CFD, it was possible to analyze the lift improvement with the addition of the Gurney flaps by evaluating the pressure difference between the pressure surface and the negative pressure surface, and the drag improvement was due to the Gurney flaps obstructing the chordal flow of the fluid in the wake. For the 2D NACA-63415 airfoil, the drag coefficient increases with the increase in the head angle, while the lift coefficient increases and then decreases. The flap height divided by the local chord length of the Gurney flaps is 0.01, and the lift-to-drag ratio is the highest when the head angle is 4°. For the NACA-638xx turbine, the addition of Gurney flaps significantly increases the axial thrust coefficient. At lower tip speed ratios, the effect of the Gurney flaps on the rotor’s power coefficient is limited, with the greatest increase in the power coefficient at a tip speed ratio of 6 and a decrease in the power coefficient increase as the tip speed ratio increases. Increasing the height of the Gurney flaps can increase the peak power coefficient, but the power performance decreases at high tip speed ratios. The Gurney flaps distributed at the root of the rotor have less effect on the power performance. A 0.4 local radius spread of the Gurney flaps increases the peak turbine power coefficient by only 0.34%, while full-length Gurney flaps can increase the peaked blade power coefficient by 10.68%, indicating that Gurney flaps can be used to design a new HAOCT.https://www.mdpi.com/2077-1312/11/11/2188horizontal axis ocean current turbinecomputational fluid dynamicspassive flow controlGurney flap |
| spellingShingle | Zhaoyong Mao Tianqi Zhang Guangyong Yang Wenlong Tian Effects of Gurney Flaps on the Performance of a Horizontal Axis Ocean Current Turbine Journal of Marine Science and Engineering horizontal axis ocean current turbine computational fluid dynamics passive flow control Gurney flap |
| title | Effects of Gurney Flaps on the Performance of a Horizontal Axis Ocean Current Turbine |
| title_full | Effects of Gurney Flaps on the Performance of a Horizontal Axis Ocean Current Turbine |
| title_fullStr | Effects of Gurney Flaps on the Performance of a Horizontal Axis Ocean Current Turbine |
| title_full_unstemmed | Effects of Gurney Flaps on the Performance of a Horizontal Axis Ocean Current Turbine |
| title_short | Effects of Gurney Flaps on the Performance of a Horizontal Axis Ocean Current Turbine |
| title_sort | effects of gurney flaps on the performance of a horizontal axis ocean current turbine |
| topic | horizontal axis ocean current turbine computational fluid dynamics passive flow control Gurney flap |
| url | https://www.mdpi.com/2077-1312/11/11/2188 |
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