Numerical Calculations of VGs Influence on Aerodynamic Characteristics of Airfoil |
| R. Gnatowska, K. Gajewska, R. Kańtoch
Częstochowa University of Technology, 42-201 Częstochowa, Poland |
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| Flow separation on aerodynamically shaped bodies is always an unfavorable phenomenon responsible for substantial energy losses. Passive vortex generators (VGs) are widely used as a simple and effective tool to delay or suppress separation on an airfoil. Despite many studies and practical applications of this flow control method, there are still many scientific problems related to VGs application that need to be solved. For example, the optimal VGs geometry and their positioning to have the best aerodynamic effect have not always been studied in enough detail. The present work describes a computational fluid dynamic analysis of VGs application on an airfoil NLF-MOD22B with a flap model of the Extra EA-400. A case of an airfoil with a strongly deflected rear flap inducing a strong detachment was considered. A vortex generator was located at the lower side of the airfoil near the local trailing edge upstream of the flap. The analysis of the results, especially the pressure distribution and skin friction coefficient on the airfoil indicates that VGs are capable of delaying flow separation over the flap. It was observed that both the lift and drag coefficient depends on the applied shape of the VGs. The research indicates that the selection of the optimal geometry of the disturbing element is very difficult: although its application increases the lifting force of the entire profile, on the other hand, it also influences the drag force and as a result, the maximum lift-drag ratio (CL/CD) is similar to the case without VGs. An optimistic result, however, is the observation that a beneficial effect is noticed when analyzing the flop itself. |
DOI:10.12693/APhysPolA.139.586 topics: airfoil, numerical calculations, aerodynamics, flow control |