Experiment and numerical simulation of an aluminum circular-blade butterfly wind turbine
To reduce costs involved in manufacturing small wind turbines, an aluminum circular-blade butterfly wind turbine (ACBBWT) has been developed, in which four blades of the turbine were extruded and bent to shape then attached directly to a rotating flange. The ACBBWT is a vertical axis wind turbine (V...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2016-03-01
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| Series: | Journal of Fluid Science and Technology |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/jfst/11/2/11_2016jfst0010/_pdf/-char/en |
| _version_ | 1819364473859735552 |
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| author | Yutaka HARA Akira SHIOZAKI Hiroaki NISHIONO Shigenori SAITO Keisuke SHIOYA Takahiro SUMI Yuhei MATSUBARA Yoshiyuki YASUMOTO Katsuhiro TAKAGAKI Shohei KOGO |
| author_facet | Yutaka HARA Akira SHIOZAKI Hiroaki NISHIONO Shigenori SAITO Keisuke SHIOYA Takahiro SUMI Yuhei MATSUBARA Yoshiyuki YASUMOTO Katsuhiro TAKAGAKI Shohei KOGO |
| author_sort | Yutaka HARA |
| collection | DOAJ |
| description | To reduce costs involved in manufacturing small wind turbines, an aluminum circular-blade butterfly wind turbine (ACBBWT) has been developed, in which four blades of the turbine were extruded and bent to shape then attached directly to a rotating flange. The ACBBWT is a vertical axis wind turbine (VAWT) and the rotor diameter of the prototype is 2.06 m. Experiments to obtain the output performance were conducted outdoors using an axial blower; however, the data obtained were rather scattered due to the effects of natural wind. Therefore, performance curves in the high wind speed range are predicted by fitting theoretical curves based on the Blade Element Momentum (BEM) theory, in which modification of virtual incidence due to flow curvature effects is included. Three-dimensional computational fluid dynamics (CFD) analysis of a circular-blade wind turbine model (dia. 2 m) with a shape almost identical to that of the experimental rotor is performed. The results assuming an energy-conversion efficiency of 0.8 agree well with the experimental results at 7 m/s. CFD analysis shows that tip vortices are shed from the top and bottom parts of a circular blade, as with straight-blade VAWTs. However, vorticity in the circular-blade case is lower than that in the straight-blade case, and the cross-section of each tip vortex shed from circular blades appears to be in the shape of a deformed ellipse. In cases of small tip speed ratios, vortex shedding caused by the dynamic stall phenomena is observed around the equator plane in both the downstream and upstream regions, and the vortex shed in the downstream region by a circular blade forms a looped shape. Since distributions of surface pressure and skin friction obtained by 3D-CFD have a similar pattern in both the upstream and downstream regions, which is related to vortex shedding, it is considered that the vortex in the upstream region is likely to also have a looped shape. |
| first_indexed | 2024-12-24T22:59:30Z |
| format | Article |
| id | doaj.art-f320dd256cea4e33832e494f969e7fd7 |
| institution | Directory Open Access Journal |
| issn | 1880-5558 |
| language | English |
| last_indexed | 2024-12-24T22:59:30Z |
| publishDate | 2016-03-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Journal of Fluid Science and Technology |
| spelling | doaj.art-f320dd256cea4e33832e494f969e7fd72022-12-21T16:35:11ZengThe Japan Society of Mechanical EngineersJournal of Fluid Science and Technology1880-55582016-03-01112JFST0010JFST001010.1299/jfst.2016jfst0010jfstExperiment and numerical simulation of an aluminum circular-blade butterfly wind turbineYutaka HARA0Akira SHIOZAKI1Hiroaki NISHIONO2Shigenori SAITO3Keisuke SHIOYA4Takahiro SUMI5Yuhei MATSUBARA6Yoshiyuki YASUMOTO7Katsuhiro TAKAGAKI8Shohei KOGO9Graduate School of Engineering, Tottori UniversityR&D Laboratory, Sinfonia Technology Co., Ltd.R&D Laboratory, Sinfonia Technology Co., Ltd.Technology Division, Nikkeikin Aluminium Core Technology Co., Ltd.Product Development Group, Technology Division, Nikkeikin Aluminium Core Technology Co., Ltd.Department of Advanced Technology Fusion, Saga UniversityGraduate School of Engineering, Tottori UniversityTottori Prefecture Land ManagementGraduate School of Engineering, Tottori UniversityGraduate School of Engineering, Tottori UniversityTo reduce costs involved in manufacturing small wind turbines, an aluminum circular-blade butterfly wind turbine (ACBBWT) has been developed, in which four blades of the turbine were extruded and bent to shape then attached directly to a rotating flange. The ACBBWT is a vertical axis wind turbine (VAWT) and the rotor diameter of the prototype is 2.06 m. Experiments to obtain the output performance were conducted outdoors using an axial blower; however, the data obtained were rather scattered due to the effects of natural wind. Therefore, performance curves in the high wind speed range are predicted by fitting theoretical curves based on the Blade Element Momentum (BEM) theory, in which modification of virtual incidence due to flow curvature effects is included. Three-dimensional computational fluid dynamics (CFD) analysis of a circular-blade wind turbine model (dia. 2 m) with a shape almost identical to that of the experimental rotor is performed. The results assuming an energy-conversion efficiency of 0.8 agree well with the experimental results at 7 m/s. CFD analysis shows that tip vortices are shed from the top and bottom parts of a circular blade, as with straight-blade VAWTs. However, vorticity in the circular-blade case is lower than that in the straight-blade case, and the cross-section of each tip vortex shed from circular blades appears to be in the shape of a deformed ellipse. In cases of small tip speed ratios, vortex shedding caused by the dynamic stall phenomena is observed around the equator plane in both the downstream and upstream regions, and the vortex shed in the downstream region by a circular blade forms a looped shape. Since distributions of surface pressure and skin friction obtained by 3D-CFD have a similar pattern in both the upstream and downstream regions, which is related to vortex shedding, it is considered that the vortex in the upstream region is likely to also have a looped shape.https://www.jstage.jst.go.jp/article/jfst/11/2/11_2016jfst0010/_pdf/-char/enwind powervertical axis wind turbinecircular bladealuminum extrusioncomputational fluid dynamicsvorticitysurface pressureskin friction |
| spellingShingle | Yutaka HARA Akira SHIOZAKI Hiroaki NISHIONO Shigenori SAITO Keisuke SHIOYA Takahiro SUMI Yuhei MATSUBARA Yoshiyuki YASUMOTO Katsuhiro TAKAGAKI Shohei KOGO Experiment and numerical simulation of an aluminum circular-blade butterfly wind turbine Journal of Fluid Science and Technology wind power vertical axis wind turbine circular blade aluminum extrusion computational fluid dynamics vorticity surface pressure skin friction |
| title | Experiment and numerical simulation of an aluminum circular-blade butterfly wind turbine |
| title_full | Experiment and numerical simulation of an aluminum circular-blade butterfly wind turbine |
| title_fullStr | Experiment and numerical simulation of an aluminum circular-blade butterfly wind turbine |
| title_full_unstemmed | Experiment and numerical simulation of an aluminum circular-blade butterfly wind turbine |
| title_short | Experiment and numerical simulation of an aluminum circular-blade butterfly wind turbine |
| title_sort | experiment and numerical simulation of an aluminum circular blade butterfly wind turbine |
| topic | wind power vertical axis wind turbine circular blade aluminum extrusion computational fluid dynamics vorticity surface pressure skin friction |
| url | https://www.jstage.jst.go.jp/article/jfst/11/2/11_2016jfst0010/_pdf/-char/en |
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