To apply the experimental data measured in a wind tunnel for a scaled aircraft to a free-flying model, conditions of dynamical similarity must be met or scaling procedures introduced. The scaling methods should correct the wind tunnel data regarding model support, wall interference, and lower Reynolds number. To include the necessary corrections, the current scaling techniques use computational fluid dynamics (CFD) in combination with measurements in cryogenic wind tunnels. There are a few methods that enable preliminary calculations of typical corrections considering specific measurement conditions and volume limitation of test section. The purpose of this paper is to present one possible approach to estimating corrections due to sting interference and difference in Reynolds number between the real airplane in cruise regime and its 1:100 model in the small wind tunnel AT-1. The analysis gives results for correction of axial and normal force coefficients. The results of this analysis indicate that the Reynolds number effects and the problem of installation of internal force balance are quite large. Therefore, the wind tunnel AT-1 has limited usage for aerodynamic coefficient determination of transport airplanes, like Dash 8 Q400 analyzed in this paper.
K. Pettersson and A. Rizzi, "Aerodynamic Scaling to Free Flight Conditions: Past and Present," Progress in Aerospace Sciences, vol. 44, no. 4, pp. 295-313, 2008.
J. B. Barlow, W. H. Rae and A. Pope, Low-Speed Wind Tunnel Testing, New York: John Wiley &Sons, 1999.
B. Horsten, "Low-Speed Model Support Interference - Elements of an Expert System," Delft University of Technology, Delft, 2009.
D. M. Bushnell, "Scaling: Wind Tunnel to Flight," Annual Review of Fluid Mechanics, vol. 38, pp. 111-128, 2006.
L. W. Traub, "Drag Extrapolation to Higher Reynolds Number," Journal of Aircraft, vol. 46, no. 4, pp. 1458-1461, 2009.
M. Mirzaei, M. H. Karimi and M. A. Vaziri, "An Investigation of a Tactical Cargo Aircraft Aft Body Drag Reduction Based on CFD Analysis and Wind Tunnel Tests," Aerospace Science and Technology, vol. 23, no. 1, pp. 263-269, 2012.
K. Pettersson and A. Rizzi, "Reynolds Number Effects Identified with CFD Methods Compared to Semi-Empirical Methods," in 25th International Congress of the Aeronautical Sciences (ICAS 2006), Hamburg, Germany, 2006.
M. Maina, N. Corby, E. L. Crocker, P. J. Hammond and P. W. C. Wong, "A feasiblity study on designing model support systems for a blended wing body configuration in a transonic wind tunnel," Aeronautical Journal, vol. 110, no. 1103, p. 53.62, 2006.
R. Rudnik and E. Germain, "Reynolds Number Scaling Effects on the European High-Lift Project Configurations," Journal of Aircraft, vol. 46, no. 4, pp. 1140-1151, 2009.
B. Pamadi, "Performance, Stability, Dynamics, and Control of Airplanes," AIAA, Reston, Virginia, 1998.
S. Janković, Aircraft Flight Mechanics, Zagreb: Faculty of Mechanical Engineering and Naval Architecture, 2002.
A. A. Лебедев, "Динамика полета: Машиностроение," Москва, 1973.
Guest Editor: Eleonora Papadimitriou, PhD
Editors: Dario Babić, PhD; Marko Matulin, PhD; Marko Ševrović, PhD.
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