Numerical study of separation on the trailing edge of a symmetrical airfoil at a low Reynolds number
| Autor: | Can Huang, Feng Guo, Juanmian Lei |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Symmetrical airfoil
Airfoil Laminar separation bubble Trailing-edge separation Angle of attack Mechanical Engineering Aerospace Engineering Mechanics Vortex generator Starting vortex Vortex shedding Vortex ring Vortex Physics::Fluid Dynamics Classical mechanics Condensed Matter::Superconductivity Vortex lift Low Reynolds number Simulation Mathematics |
| Zdroj: | Chinese Journal of Aeronautics. 26:918-925 |
| ISSN: | 1000-9361 |
| DOI: | 10.1016/j.cja.2013.06.005 |
| Popis: | This study focuses on the trailing-edge separation of a symmetrical airfoil at a low Reynolds number. Finite volume method is adopted to solve the unsteady Reynolds-averaged Navier–Stokes (RANS) equation. Flow of the symmetrical airfoil SD8020 at a low Reynolds number has been simulated. Laminar separation bubble in the flow field of the airfoil is observed and process of unsteady bubble burst and vortex shedding from airfoil surfaces is investigated. The time-dependent lift coefficient is characteristic of periodic fluctuations and the lift curve varies nonlinearly with the attack of angle. Laminar separation occurs on both surfaces of airfoil at small angles of attack. With the increase of angle of attack, laminar separation occurs and then reattaches near the trailing edge on the upper surface of airfoil, which forms laminar separation bubble. When the attack of angle reaches certain value, the laminar separation bubble is unstable and produces two kinds of large scale vortex, i.e. primary vortex and secondary vortex. The periodic processes that include secondary vortex production, motion of secondary vortex and vortex shedding cause fluctuation of the lift coefficient. The periodic time varies with attack of angle. The secondary vortex is relatively stronger than the primary vortex, which means its influence is relatively stronger than the primary vortex. |
| Databáze: | OpenAIRE |
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