Self-Starting Improvement and Performance Enhancement in Darrieus VAWTs Using Auxiliary Blades and Deflectors
The Darrieus vertical axis wind turbine (VAWT) is categorized as a lift-based turbomachine. It faces challenges in the low tip speed ratio (TSR) range and requires initial torque for the starting operation. Ongoing efforts are being made to enhance the turbine’s self-starting capability. In this stu...
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2024-11-01
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| author | Farzad Ghafoorian Erfan Enayati Seyed Reza Mirmotahari Hui Wan |
| author_facet | Farzad Ghafoorian Erfan Enayati Seyed Reza Mirmotahari Hui Wan |
| author_sort | Farzad Ghafoorian |
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| description | The Darrieus vertical axis wind turbine (VAWT) is categorized as a lift-based turbomachine. It faces challenges in the low tip speed ratio (TSR) range and requires initial torque for the starting operation. Ongoing efforts are being made to enhance the turbine’s self-starting capability. In this study, Computational Fluid Dynamics (CFD) simulations were utilized to tackle the identified challenge. The Unsteady Reynolds-Averaged Navier–Stokes (URANS) approach was employed, combined with the shear–stress transport (SST) <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></semantics></math></inline-formula> turbulence model, to resolve fluid flow equations. The investigation focused on optimizing the placement of auxiliary blades by considering design parameters such as the pitch angle and horizontal and vertical distances. The goal was to increase the turbine efficiency and initial torque in the low-TSR range while minimizing efficiency loss at high-TSR ranges, which is the primary challenge of auxiliary blade installation. Implementing the auxiliary blade successfully extended the rotor’s operational range, shifting the rotor operation’s onset from TSR 1.4 to 0.7. The optimal configuration for installing the auxiliary blade involves a pitch angle of 0°, a horizontal ratio of 0.52, and a vertical ratio of 0.41. To address the ineffectiveness of auxiliary blades at high-TSRs, installing deflectors in various configurations was explored. Introducing a double deflector can significantly enhance the overall efficiency of the conventional Darrieus VAWT and the optimum rotor with the auxiliary blade by 47% and 73% at TSR = 2.5, respectively. |
| format | Article |
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| language | English |
| publishDate | 2024-11-01 |
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| series | Machines |
| spelling | doaj-art-fa908f5b53804f4abd5091bc945bd7c72025-08-20T01:54:07ZengMDPI AGMachines2075-17022024-11-01121180610.3390/machines12110806Self-Starting Improvement and Performance Enhancement in Darrieus VAWTs Using Auxiliary Blades and DeflectorsFarzad Ghafoorian0Erfan Enayati1Seyed Reza Mirmotahari2Hui Wan3Department of Mechanical and Aerospace Engineering, University of Colorado, Colorado Springs, CO 80918, USADepartment of Energy Conversion, School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16846-13114, IranDepartment of Energy Conversion, School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16846-13114, IranDepartment of Mechanical and Aerospace Engineering, University of Colorado, Colorado Springs, CO 80918, USAThe Darrieus vertical axis wind turbine (VAWT) is categorized as a lift-based turbomachine. It faces challenges in the low tip speed ratio (TSR) range and requires initial torque for the starting operation. Ongoing efforts are being made to enhance the turbine’s self-starting capability. In this study, Computational Fluid Dynamics (CFD) simulations were utilized to tackle the identified challenge. The Unsteady Reynolds-Averaged Navier–Stokes (URANS) approach was employed, combined with the shear–stress transport (SST) <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></semantics></math></inline-formula> turbulence model, to resolve fluid flow equations. The investigation focused on optimizing the placement of auxiliary blades by considering design parameters such as the pitch angle and horizontal and vertical distances. The goal was to increase the turbine efficiency and initial torque in the low-TSR range while minimizing efficiency loss at high-TSR ranges, which is the primary challenge of auxiliary blade installation. Implementing the auxiliary blade successfully extended the rotor’s operational range, shifting the rotor operation’s onset from TSR 1.4 to 0.7. The optimal configuration for installing the auxiliary blade involves a pitch angle of 0°, a horizontal ratio of 0.52, and a vertical ratio of 0.41. To address the ineffectiveness of auxiliary blades at high-TSRs, installing deflectors in various configurations was explored. Introducing a double deflector can significantly enhance the overall efficiency of the conventional Darrieus VAWT and the optimum rotor with the auxiliary blade by 47% and 73% at TSR = 2.5, respectively.https://www.mdpi.com/2075-1702/12/11/806Darrieus VAWTauxiliary bladesdeflectorsself-starting capabilitylow and high-TSR rangeblade stall |
| spellingShingle | Farzad Ghafoorian Erfan Enayati Seyed Reza Mirmotahari Hui Wan Self-Starting Improvement and Performance Enhancement in Darrieus VAWTs Using Auxiliary Blades and Deflectors Machines Darrieus VAWT auxiliary blades deflectors self-starting capability low and high-TSR range blade stall |
| title | Self-Starting Improvement and Performance Enhancement in Darrieus VAWTs Using Auxiliary Blades and Deflectors |
| title_full | Self-Starting Improvement and Performance Enhancement in Darrieus VAWTs Using Auxiliary Blades and Deflectors |
| title_fullStr | Self-Starting Improvement and Performance Enhancement in Darrieus VAWTs Using Auxiliary Blades and Deflectors |
| title_full_unstemmed | Self-Starting Improvement and Performance Enhancement in Darrieus VAWTs Using Auxiliary Blades and Deflectors |
| title_short | Self-Starting Improvement and Performance Enhancement in Darrieus VAWTs Using Auxiliary Blades and Deflectors |
| title_sort | self starting improvement and performance enhancement in darrieus vawts using auxiliary blades and deflectors |
| topic | Darrieus VAWT auxiliary blades deflectors self-starting capability low and high-TSR range blade stall |
| url | https://www.mdpi.com/2075-1702/12/11/806 |
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