Performance Characteristics of an Orthopter-Type Vertical Axis Wind Turbine in Shear Flows
To properly conduct a micro-siting of an orthopter-type vertical axis wind turbine (O-VAWT) in the built environment, this study investigated the effects of horizontal shear flow on the power performance characteristics of an O-VAWT by performing wind tunnel experiments and computational fluid dynam...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-03-01
|
| Series: | Applied Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3417/10/5/1778 |
| _version_ | 1819330613509881856 |
|---|---|
| author | Rudi Purwo Wijayanto Takaaki Kono Takahiro Kiwata |
| author_facet | Rudi Purwo Wijayanto Takaaki Kono Takahiro Kiwata |
| author_sort | Rudi Purwo Wijayanto |
| collection | DOAJ |
| description | To properly conduct a micro-siting of an orthopter-type vertical axis wind turbine (O-VAWT) in the built environment, this study investigated the effects of horizontal shear flow on the power performance characteristics of an O-VAWT by performing wind tunnel experiments and computational fluid dynamics (CFD) simulations. A uniform flow and two types of shear flow (advancing side faster shear flow (ASF-SF) and retreating side faster shear flow (RSF-SF)) were employed as the approaching flow to the O-VAWT. The ASF-SF had a higher velocity on the advancing side of the rotor. The RSF-SF had a higher velocity on the retreating side of the rotor. For each type of shear flow, three shear strengths (<i>Γ</i> = 0.28, 0.40 and 0.51) were set. In the ASF-SF cases, the power coefficients (<i>C<sub>p</sub></i>) were significantly higher than the uniform flow case at all tip speed ratios (<i>λ</i>) and increased with <i>Γ</i>. In the RSF-SF cases, <i>C<sub>P</sub></i> increased with <i>Γ</i>. However, when <i>Γ</i> = 0.28, the <i>C<sub>P</sub></i> was lower than the uniform flow case at all λ. When <i>Γ</i> = 0.51, the <i>C<sub>P</sub></i> was higher than the uniform flow case except at low λ; however, it was lower than the ASF-SF case with <i>Γ</i> = 0.28. The causes of the features of <i>C<sub>P</sub></i> were discussed through the analysis of the variation of blade torque coefficient, its rotor-revolution component and its blade-rotation component with azimuthal angle by using the CFD results for flow fields (i.e., horizontal velocity vectors, pressure and vorticity). These results indicate that a location where ASF-SFs with high <i>Γ</i> values dominantly occur is ideal for installing the O-VAWT. |
| first_indexed | 2024-12-24T14:01:19Z |
| format | Article |
| id | doaj.art-dc07a4f9f219400cad8fd57b96ecddab |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-12-24T14:01:19Z |
| publishDate | 2020-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-dc07a4f9f219400cad8fd57b96ecddab2022-12-21T16:52:29ZengMDPI AGApplied Sciences2076-34172020-03-01105177810.3390/app10051778app10051778Performance Characteristics of an Orthopter-Type Vertical Axis Wind Turbine in Shear FlowsRudi Purwo Wijayanto0Takaaki Kono1Takahiro Kiwata2Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, JapanInstitute of Science and Engineering, Kanazawa University, Kanazawa 920-1192, JapanInstitute of Science and Engineering, Kanazawa University, Kanazawa 920-1192, JapanTo properly conduct a micro-siting of an orthopter-type vertical axis wind turbine (O-VAWT) in the built environment, this study investigated the effects of horizontal shear flow on the power performance characteristics of an O-VAWT by performing wind tunnel experiments and computational fluid dynamics (CFD) simulations. A uniform flow and two types of shear flow (advancing side faster shear flow (ASF-SF) and retreating side faster shear flow (RSF-SF)) were employed as the approaching flow to the O-VAWT. The ASF-SF had a higher velocity on the advancing side of the rotor. The RSF-SF had a higher velocity on the retreating side of the rotor. For each type of shear flow, three shear strengths (<i>Γ</i> = 0.28, 0.40 and 0.51) were set. In the ASF-SF cases, the power coefficients (<i>C<sub>p</sub></i>) were significantly higher than the uniform flow case at all tip speed ratios (<i>λ</i>) and increased with <i>Γ</i>. In the RSF-SF cases, <i>C<sub>P</sub></i> increased with <i>Γ</i>. However, when <i>Γ</i> = 0.28, the <i>C<sub>P</sub></i> was lower than the uniform flow case at all λ. When <i>Γ</i> = 0.51, the <i>C<sub>P</sub></i> was higher than the uniform flow case except at low λ; however, it was lower than the ASF-SF case with <i>Γ</i> = 0.28. The causes of the features of <i>C<sub>P</sub></i> were discussed through the analysis of the variation of blade torque coefficient, its rotor-revolution component and its blade-rotation component with azimuthal angle by using the CFD results for flow fields (i.e., horizontal velocity vectors, pressure and vorticity). These results indicate that a location where ASF-SFs with high <i>Γ</i> values dominantly occur is ideal for installing the O-VAWT.https://www.mdpi.com/2076-3417/10/5/1778orthoptervertical axis wind turbinepower coefficienttorque coefficientshear flowwind tunnelcfddelayed detached-eddy simulation |
| spellingShingle | Rudi Purwo Wijayanto Takaaki Kono Takahiro Kiwata Performance Characteristics of an Orthopter-Type Vertical Axis Wind Turbine in Shear Flows Applied Sciences orthopter vertical axis wind turbine power coefficient torque coefficient shear flow wind tunnel cfd delayed detached-eddy simulation |
| title | Performance Characteristics of an Orthopter-Type Vertical Axis Wind Turbine in Shear Flows |
| title_full | Performance Characteristics of an Orthopter-Type Vertical Axis Wind Turbine in Shear Flows |
| title_fullStr | Performance Characteristics of an Orthopter-Type Vertical Axis Wind Turbine in Shear Flows |
| title_full_unstemmed | Performance Characteristics of an Orthopter-Type Vertical Axis Wind Turbine in Shear Flows |
| title_short | Performance Characteristics of an Orthopter-Type Vertical Axis Wind Turbine in Shear Flows |
| title_sort | performance characteristics of an orthopter type vertical axis wind turbine in shear flows |
| topic | orthopter vertical axis wind turbine power coefficient torque coefficient shear flow wind tunnel cfd delayed detached-eddy simulation |
| url | https://www.mdpi.com/2076-3417/10/5/1778 |
| work_keys_str_mv | AT rudipurwowijayanto performancecharacteristicsofanorthoptertypeverticalaxiswindturbineinshearflows AT takaakikono performancecharacteristicsofanorthoptertypeverticalaxiswindturbineinshearflows AT takahirokiwata performancecharacteristicsofanorthoptertypeverticalaxiswindturbineinshearflows |