![]() ![]() Second digit describing the distance of maximum camber from the airfoil leading edge in tenths of the chord.First digit describing maximum camber as percentage of the chord.The NACA four-digit wing sections define the profile by: These figures and shapes transmitted the sort of information to engineers that allowed them to select specific airfoils for desired performance characteristics of specific aircraft. Engineers could quickly see the peculiarities of each airfoil shape, and the numerical designator ("NACA 2415," for instance) specified camber lines, maximum thickness, and special nose features. By 1929, Langley had developed this system to the point where the numbering system was complemented by an airfoil cross-section, and the complete catalog of 78 airfoils appeared in the NACA's annual report for 1933. According to the NASA website:ĭuring the late 1920s and into the 1930s, the NACA developed a series of thoroughly tested airfoils and devised a numerical designation for each airfoil - a four digit number that represented the airfoil section's critical geometric properties. NACA initially developed the numbered airfoil system which was further refined by the United States Air Force at Langley Research Center. The NACA airfoil series is a set of standardized airfoil shapes developed by this agency, which became widely used in the design of aircraft wings. It played a crucial role in advancing aviation technology, including the development of airfoils, which are the cross-sectional shapes of wings and other aerodynamic surfaces. federal agency founded in 1915 to undertake, promote, and institutionalize aeronautical research. NACA stands for the National Advisory Committee for Aeronautics, which was a U.S. thickness 5: Camber 6: Upper surface 7: Trailing edge 8: Camber mean-line 9: Lower surface Profile lines – 1: Chord, 2: Camber, 3: Length, 4: Midline A: blue line = chord, green line = camber mean-line, B: leading-edge radius, C: xy coordinates for the profile geometry (chord = x axis y axis line on that leading edge) NREL/SR-440-6918Ĭhen Y, Gao Z (2009) Application of gamma-theta transition model to flows around airfoils.Wing shape Profile geometry – 1: Zero-lift line 2: Leading edge 3: Nose circle 4: Max. Somers DM (1997) Design and experimental results for the S809 airfoil. Langtry RB (2006) A correlation-based transition model using local variables for unstructured parallelized CFD codes. J Aircr 40(4):609–615įujino M (2005) Design and development of the Honda Jet. National defense industry press, Beijingįujino M, Yoshizaki Y, Kawamura Y (2003) Natural-laminar-flow airfoil development for a lightweight business jet. ![]() Zhu Z (2011) Aerodynamic design of modern aircraft. Schrauf G (2005) Status and perspectives of laminar flow. In: Proceedings of the 14th congress of ICAS, pp 1053–1064, Bonn Thibert JJ, Reneaux J, Schmitt RV (1990) ONERA activities on drag reduction. The lift changes little with the movement of transition locations. For the forced transition, the drag increases approximately linearly with the transition location for both the upper and lower surface, but the upper-surface behaves much more significant. The upper-surface transition location moves upstream rapidly after the 4° angle of attack. For the natural transition, as the angle of attack increasing, the natural transition location on the upper surface moves upstream while the one on the lower surface moves the opposite. Results show that, the transition location has a great influence on the aerodynamic characteristics of laminar airfoil, especially on the drag. Secondly, forced transition simulations were taken to imitate the disturbed airfoil flow using k-ω SST model. Firstly, numerical simulations of natural transition of the airfoil flow at various angles of attack were carried out using γ-Re θ model. This paper focuses on the aerodynamic characteristics of a laminar airfoil named NACA65(1)412. Therefore, it is meaningful to obtain the aerodynamic characteristics of laminar airfoil both under natural transition and disturbed transition conditions. However, the laminar flow is too sensitive to be disturbed and then laminar-turbulent transition location will move forward, which results in a significant increase in drag. Laminar airfoil has extensive application prospect in the civil aviation area as its low drag characteristic. ![]()
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