Effects of Variations in Reynolds Number between 3000000 and 25000000 upon the Aerodynamic Characteristics of a Number of NACA 6-Series Airfoil Sections

摘要

An investigation was made to determine the two-dimensional lift and drag characteristics of nine NACA 6-series airfoil sections at Reynolds numbers between 3000000 and 25000000. The airfoils selected represent sections having variations in the airfoil thickness, thickness form, and camber. The characteristics of an airfoil with a split flap were determined in one instance, as was also the effect of surface roughness. Qualitative explanations in terms of flow behavior are advanced for the observed types of scale effect. Any comparison of airfoil maximum-lift characteristics can be made only if the data for the group of airfoils under consideration are available at the same Reynolds number. The choice of an optimum airfoil for maximum lift for a given application must be determined from data corresponding to the operating Reynolds number of the application.