Experimental Investigation of High-Angle-of-Attack Aerodynamics of Low-Aspect-Ratio Rectangular Wings Configured with NACA0012 Airfoil Section

Autor: Seok Ho Lee, Yong Oun Han
Rok vydání: 2019
Předmět:
Zdroj: International Journal of Aeronautical and Space Sciences. 21:303-314
ISSN: 2093-2480
2093-274X
DOI: 10.1007/s42405-019-00215-z
Popis: To examine the high-angle-of-attack (AOA) aerodynamics, the conventional lift and drag were measured in one revolution AOA by the dynamic load cell in the wind tunnel for rectangular wings of the NACA0012 section with four different aspect ratios, 3, 4, 5, and 6, at a Reynolds number of 1.0 × 105. The results were analyzed in the normal and reverse modes of the airfoil. It was found that the reverse airfoil is disadvantageous to the lifting device because of the earlier stall than the normal and the substantial drag increases before the stall. In the entire AOA range, Prandtl’s lifting line theory seems to be applicable in general, but the profiles of the lift coefficient are not linear anymore. It was also found that the drag coefficient of the normal airfoil mode is affected by the delta wing-type vortex wrap as well as the downwash, and that the downwash effect was dominated between the deep stall and the second peak. Using the expanding scales, which have an exponential decay rate with the aspect ratio, the polar plots of the four different wings overlap in one circle with a radius of 1.0 at the same origin.
Databáze: OpenAIRE
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