A New Method of Determination of the Angle of Attack on Rotating Wind Turbine Blades
The angle of attack (AoA) is the key parameter when extracting the aerodynamic polar from the rotating blade sections of a wind turbine. However, the determination of AoA is not straightforward using computational fluid dynamics (CFD) or measurement. Since the incoming streamlines are bent because o...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2019-10-01
|
| Series: | Energies |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1073/12/20/4012 |
| _version_ | 1811304970433069056 |
|---|---|
| author | Wei Zhong Wen Zhong Shen Tong Guang Wang Wei Jun Zhu |
| author_facet | Wei Zhong Wen Zhong Shen Tong Guang Wang Wei Jun Zhu |
| author_sort | Wei Zhong |
| collection | DOAJ |
| description | The angle of attack (AoA) is the key parameter when extracting the aerodynamic polar from the rotating blade sections of a wind turbine. However, the determination of AoA is not straightforward using computational fluid dynamics (CFD) or measurement. Since the incoming streamlines are bent because of the complex inductions of the rotor, discrepancies exist between various existing determination methods, especially in the tip region. In the present study, flow characteristics in the region near wind turbine blades are analyzed in detail using CFD results of flows past the NREL UAE Phase VI rotor. It is found that the local flow determining AOA changes rapidly in the vicinity of the blade. Based on this finding, the concepts of effective AoA as well as nominal AoA are introduced, leading to a new method of AOA determination. The new method has 5 steps: (1) Find the distributed vortices on the blade surface; (2) select two monitoring points per cross-section close to the aerodynamic center on both pressure and suction sides with an equal distance from the rotor plane; (3) subtract the blade self-induction from the velocity at each monitoring point; (4) average the velocity of the two monitoring points obtained in Step 3; (5) determine the AoA using the velocity obtained in Step 4. Since the monitoring points for the first time can be set very close to the aerodynamic center, leading to an excellent estimation of AoA. The aerodynamic polar extracted through determination of the effective AoA exhibits a consistent regularity for both the mid-board and tip sections, which has never been obtained by the existing determination methods. |
| first_indexed | 2024-04-13T08:18:09Z |
| format | Article |
| id | doaj.art-85fc4386c9c348258c67f1ac3af5aed3 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-13T08:18:09Z |
| publishDate | 2019-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-85fc4386c9c348258c67f1ac3af5aed32022-12-22T02:54:44ZengMDPI AGEnergies1996-10732019-10-011220401210.3390/en12204012en12204012A New Method of Determination of the Angle of Attack on Rotating Wind Turbine BladesWei Zhong0Wen Zhong Shen1Tong Guang Wang2Wei Jun Zhu3Jiangsu Key Laboratory of Hi-Tech Research for Wind Turbine Design, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaDepartment of Wind Energy, Technical University of Denmark, 2800 Lyngby, DenmarkJiangsu Key Laboratory of Hi-Tech Research for Wind Turbine Design, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaSchool of Hydraulic Energy and Power Engineering, Yangzhou University, Yangzhou 225009, ChinaThe angle of attack (AoA) is the key parameter when extracting the aerodynamic polar from the rotating blade sections of a wind turbine. However, the determination of AoA is not straightforward using computational fluid dynamics (CFD) or measurement. Since the incoming streamlines are bent because of the complex inductions of the rotor, discrepancies exist between various existing determination methods, especially in the tip region. In the present study, flow characteristics in the region near wind turbine blades are analyzed in detail using CFD results of flows past the NREL UAE Phase VI rotor. It is found that the local flow determining AOA changes rapidly in the vicinity of the blade. Based on this finding, the concepts of effective AoA as well as nominal AoA are introduced, leading to a new method of AOA determination. The new method has 5 steps: (1) Find the distributed vortices on the blade surface; (2) select two monitoring points per cross-section close to the aerodynamic center on both pressure and suction sides with an equal distance from the rotor plane; (3) subtract the blade self-induction from the velocity at each monitoring point; (4) average the velocity of the two monitoring points obtained in Step 3; (5) determine the AoA using the velocity obtained in Step 4. Since the monitoring points for the first time can be set very close to the aerodynamic center, leading to an excellent estimation of AoA. The aerodynamic polar extracted through determination of the effective AoA exhibits a consistent regularity for both the mid-board and tip sections, which has never been obtained by the existing determination methods.https://www.mdpi.com/1996-1073/12/20/4012wind turbineaerodynamicsangle of attackblade element momentumdownwashcomputational fluid dynamics |
| spellingShingle | Wei Zhong Wen Zhong Shen Tong Guang Wang Wei Jun Zhu A New Method of Determination of the Angle of Attack on Rotating Wind Turbine Blades Energies wind turbine aerodynamics angle of attack blade element momentum downwash computational fluid dynamics |
| title | A New Method of Determination of the Angle of Attack on Rotating Wind Turbine Blades |
| title_full | A New Method of Determination of the Angle of Attack on Rotating Wind Turbine Blades |
| title_fullStr | A New Method of Determination of the Angle of Attack on Rotating Wind Turbine Blades |
| title_full_unstemmed | A New Method of Determination of the Angle of Attack on Rotating Wind Turbine Blades |
| title_short | A New Method of Determination of the Angle of Attack on Rotating Wind Turbine Blades |
| title_sort | new method of determination of the angle of attack on rotating wind turbine blades |
| topic | wind turbine aerodynamics angle of attack blade element momentum downwash computational fluid dynamics |
| url | https://www.mdpi.com/1996-1073/12/20/4012 |
| work_keys_str_mv | AT weizhong anewmethodofdeterminationoftheangleofattackonrotatingwindturbineblades AT wenzhongshen anewmethodofdeterminationoftheangleofattackonrotatingwindturbineblades AT tongguangwang anewmethodofdeterminationoftheangleofattackonrotatingwindturbineblades AT weijunzhu anewmethodofdeterminationoftheangleofattackonrotatingwindturbineblades AT weizhong newmethodofdeterminationoftheangleofattackonrotatingwindturbineblades AT wenzhongshen newmethodofdeterminationoftheangleofattackonrotatingwindturbineblades AT tongguangwang newmethodofdeterminationoftheangleofattackonrotatingwindturbineblades AT weijunzhu newmethodofdeterminationoftheangleofattackonrotatingwindturbineblades |