Unsteady aerodynamics over surface of a chambered airfoil at stall angle and low Reynolds number
The proposal of this paper is clear to reveal and understand the unsteady flow characteristics over the surface of chambered airfoil operating especially at low Reynolds numbers by detecting boundary layer separation and laminar separation bubble (LSB). Experiments including smoke-wire technique for...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
EDP Sciences
2022-01-01
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| Series: | EPJ Web of Conferences |
| Online Access: | https://www.epj-conferences.org/articles/epjconf/pdf/2022/13/epjconf_efm2019_01016.pdf |
| _version_ | 1811308802573598720 |
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| author | Genç Gamze Koca Kemal Genç Mustafa Serdar |
| author_facet | Genç Gamze Koca Kemal Genç Mustafa Serdar |
| author_sort | Genç Gamze |
| collection | DOAJ |
| description | The proposal of this paper is clear to reveal and understand the unsteady flow characteristics over the surface of chambered airfoil operating especially at low Reynolds numbers by detecting boundary layer separation and laminar separation bubble (LSB). Experiments including smoke-wire technique for flow visualization, velocity measurement via hot-wire sensor and quasi-wall shear stress measurement by means of the hot-film sensor have been performed over the suction surface of NACA 4412 airfoil at Reynolds number of 5x104 and angle of attack of 14°. Experiments indicate that the airfoil at a stall angle exhibits the bistable characteristics over the suction surface because of the unsteady bubble bursting at low Reynolds numbers. That is, either laminar flow separates from the leading-edge of the airfoil owing to a dominant adverse pressure gradient (APG) or it does not separate along downstream. It is also noted that unsteady boundary layer formation may affect the flow characteristics by changing airfoil’s stability appreciably, causing the periodic fluctuations with the occurring bubble bursting and the leading edge and trailing edge vortex merging. This may conclude undesirable problems such as noise, vibration and flutter for the flight vehicles and wind turbines. |
| first_indexed | 2024-04-13T09:30:47Z |
| format | Article |
| id | doaj.art-1f578ef72cf34df38707d301c110f63c |
| institution | Directory Open Access Journal |
| issn | 2100-014X |
| language | English |
| last_indexed | 2024-04-13T09:30:47Z |
| publishDate | 2022-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | EPJ Web of Conferences |
| spelling | doaj.art-1f578ef72cf34df38707d301c110f63c2022-12-22T02:52:15ZengEDP SciencesEPJ Web of Conferences2100-014X2022-01-012690101610.1051/epjconf/202226901016epjconf_efm2019_01016Unsteady aerodynamics over surface of a chambered airfoil at stall angle and low Reynolds numberGenç Gamze0Koca Kemal1Genç Mustafa Serdar2Wind Engineering and Aerodynamic Research Center, Department of Energy Systems Engineering, Erciyes UniversityWind Engineering and Aerodynamic Research Center, Department of Energy Systems Engineering, Erciyes UniversityWind Engineering and Aerodynamic Research Center, Department of Energy Systems Engineering, Erciyes UniversityThe proposal of this paper is clear to reveal and understand the unsteady flow characteristics over the surface of chambered airfoil operating especially at low Reynolds numbers by detecting boundary layer separation and laminar separation bubble (LSB). Experiments including smoke-wire technique for flow visualization, velocity measurement via hot-wire sensor and quasi-wall shear stress measurement by means of the hot-film sensor have been performed over the suction surface of NACA 4412 airfoil at Reynolds number of 5x104 and angle of attack of 14°. Experiments indicate that the airfoil at a stall angle exhibits the bistable characteristics over the suction surface because of the unsteady bubble bursting at low Reynolds numbers. That is, either laminar flow separates from the leading-edge of the airfoil owing to a dominant adverse pressure gradient (APG) or it does not separate along downstream. It is also noted that unsteady boundary layer formation may affect the flow characteristics by changing airfoil’s stability appreciably, causing the periodic fluctuations with the occurring bubble bursting and the leading edge and trailing edge vortex merging. This may conclude undesirable problems such as noise, vibration and flutter for the flight vehicles and wind turbines.https://www.epj-conferences.org/articles/epjconf/pdf/2022/13/epjconf_efm2019_01016.pdf |
| spellingShingle | Genç Gamze Koca Kemal Genç Mustafa Serdar Unsteady aerodynamics over surface of a chambered airfoil at stall angle and low Reynolds number EPJ Web of Conferences |
| title | Unsteady aerodynamics over surface of a chambered airfoil at stall angle and low Reynolds number |
| title_full | Unsteady aerodynamics over surface of a chambered airfoil at stall angle and low Reynolds number |
| title_fullStr | Unsteady aerodynamics over surface of a chambered airfoil at stall angle and low Reynolds number |
| title_full_unstemmed | Unsteady aerodynamics over surface of a chambered airfoil at stall angle and low Reynolds number |
| title_short | Unsteady aerodynamics over surface of a chambered airfoil at stall angle and low Reynolds number |
| title_sort | unsteady aerodynamics over surface of a chambered airfoil at stall angle and low reynolds number |
| url | https://www.epj-conferences.org/articles/epjconf/pdf/2022/13/epjconf_efm2019_01016.pdf |
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