INVESTIGATION OF NACA 64, 2-432 AND 64,3-440 AIRFOIL SECTIONS WITH BOUNDARY-LAYER CONTROL AND AN ANALYTICAL STUDY OF THEIR POSSIBLE APPLICATIONS

摘要

NACA 64-series airfoil sections of 32- and 4O-percent-chord thick ness ratio have been derived and an investigation was made to determine the effect of boundary-layer control by means of .suction through a slot at 0.60 airfoil chord on the pressure distribution, lift, and drag characteristics of the NACA 64,2-432 and 64,3-440 airfoil sections. An analysis was made to determine whether the" maximum lift-drag ratio and the aspect ratio for maximum lift-drag ratio could be increased by the use of thick airfoils and boundary-layer control on structurally feasible wings. The section data presented and employed in the analysis were obtained with standard roughness applied to the leading edges of the models. This roughness was probably more severe than that likely to be encountered on practical aircraft under normal operating conditions;therefore, the drag coefficients measured both with and without boundary-layer control may be somewhat high as compared with practical flight values.