An Experimental Study of the Rotational Effects on Separated Turbulent Flow During Stall Delay
Three-dimensional velocity fields were measured using tomographic particle image velocimetry (Tomo-PIV) on a model of the blade of a small-scale horizontal axis wind turbine (HAWT) to study the effects of rotation on separated turbulent flows during stall delay at a global tip speed ratio (TSR) of 3...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2016
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| Online Access: | https://hdl.handle.net/10356/84603 http://hdl.handle.net/10220/41874 |
| _version_ | 1811676412584656896 |
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| author | Wu, Yanhua Lee, Hsiao Mun Tang, Hui Skote, Martin Shan, Yong |
| author2 | School of Mechanical and Aerospace Engineering |
| author_facet | School of Mechanical and Aerospace Engineering Wu, Yanhua Lee, Hsiao Mun Tang, Hui Skote, Martin Shan, Yong |
| author_sort | Wu, Yanhua |
| collection | NTU |
| description | Three-dimensional velocity fields were measured using tomographic particle image velocimetry (Tomo-PIV) on a model of the blade of a small-scale horizontal axis wind turbine (HAWT) to study the effects of rotation on separated turbulent flows during stall delay at a global tip speed ratio (TSR) of 3 and a Reynolds number of 4800. The flow fields on a static airfoil were also measured at a similar angle-of-attack (AOA) and Reynolds number for comparison. It was observed that the blade’s rotation in the streamwise direction significantly affected both the mean flow and the turbulence statistics over the suction surface. The mean velocity fields revealed that, different from the airfoil flow at large AOA, the recirculation region with reversed flow did not exist on the suction surface of the blade and the flow was rather attached. Mean spanwise flow from blade’s root to its tip was also generated by the rotation. The mean vorticity vector of the blade flow was found to be tilted in the rotational direction of the blade, as well as in the wall-normal direction. Of particular effects of the rotation on Reynolds stresses were the enhancement of 〈w2〉 and the creation of strong 〈vw〉. The production of Reynolds stresses was also affected by blade’s rotation directly through the rotational production terms and indirectly by dramatically changing the fluctuating velocity fields. The distribution of enstrophy was observed to be modified by rotation, too. |
| first_indexed | 2024-10-01T02:21:04Z |
| format | Journal Article |
| id | ntu-10356/84603 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T02:21:04Z |
| publishDate | 2016 |
| record_format | dspace |
| spelling | ntu-10356/846032023-03-04T17:15:39Z An Experimental Study of the Rotational Effects on Separated Turbulent Flow During Stall Delay Wu, Yanhua Lee, Hsiao Mun Tang, Hui Skote, Martin Shan, Yong School of Mechanical and Aerospace Engineering Rotational effects Separated turbulent flow Three-dimensional velocity fields were measured using tomographic particle image velocimetry (Tomo-PIV) on a model of the blade of a small-scale horizontal axis wind turbine (HAWT) to study the effects of rotation on separated turbulent flows during stall delay at a global tip speed ratio (TSR) of 3 and a Reynolds number of 4800. The flow fields on a static airfoil were also measured at a similar angle-of-attack (AOA) and Reynolds number for comparison. It was observed that the blade’s rotation in the streamwise direction significantly affected both the mean flow and the turbulence statistics over the suction surface. The mean velocity fields revealed that, different from the airfoil flow at large AOA, the recirculation region with reversed flow did not exist on the suction surface of the blade and the flow was rather attached. Mean spanwise flow from blade’s root to its tip was also generated by the rotation. The mean vorticity vector of the blade flow was found to be tilted in the rotational direction of the blade, as well as in the wall-normal direction. Of particular effects of the rotation on Reynolds stresses were the enhancement of 〈w2〉 and the creation of strong 〈vw〉. The production of Reynolds stresses was also affected by blade’s rotation directly through the rotational production terms and indirectly by dramatically changing the fluctuating velocity fields. The distribution of enstrophy was observed to be modified by rotation, too. MOE (Min. of Education, S’pore) Accepted version 2016-12-16T08:13:38Z 2019-12-06T15:48:08Z 2016-12-16T08:13:38Z 2019-12-06T15:48:08Z 2017 Journal Article Wu, Y., Lee, H. M., Tang, H., Skote, M., & Shan, Y. (2017). An Experimental Study of the Rotational Effects on Separated Turbulent Flow During Stall Delay. Flow, Turbulence and Combustion, 98(1), 37-56. 1386-6184 https://hdl.handle.net/10356/84603 http://hdl.handle.net/10220/41874 10.1007/s10494-016-9739-0 en Flow, Turbulence and Combustion © 2016 Springer Science+Business Media Dordrecht. This is the author created version of a work that has been peer reviewed and accepted for publication by Flow, Turbulence and Combustion, Springer Science+Business Media Dordrecht. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1007/s10494-016-9739-0]. 21 p. application/pdf |
| spellingShingle | Rotational effects Separated turbulent flow Wu, Yanhua Lee, Hsiao Mun Tang, Hui Skote, Martin Shan, Yong An Experimental Study of the Rotational Effects on Separated Turbulent Flow During Stall Delay |
| title | An Experimental Study of the Rotational Effects on Separated Turbulent Flow During Stall Delay |
| title_full | An Experimental Study of the Rotational Effects on Separated Turbulent Flow During Stall Delay |
| title_fullStr | An Experimental Study of the Rotational Effects on Separated Turbulent Flow During Stall Delay |
| title_full_unstemmed | An Experimental Study of the Rotational Effects on Separated Turbulent Flow During Stall Delay |
| title_short | An Experimental Study of the Rotational Effects on Separated Turbulent Flow During Stall Delay |
| title_sort | experimental study of the rotational effects on separated turbulent flow during stall delay |
| topic | Rotational effects Separated turbulent flow |
| url | https://hdl.handle.net/10356/84603 http://hdl.handle.net/10220/41874 |
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