Section Characteristics of a 10.5-Percent-Thick Airfoil with Area Suction as Affected by Chordwise Distribution of Permeability

Abstract

An investigation has been made at low speed of the two-dimensional aerodynamic characteristics of a 10.51-percent-thick symmetrical airfoil with area suction near the leading edge. The chordwise extent and distribution of porosity were adjusted for the purpose of obtaining a low quantity of suction-air flow for the maximum possible lift. The maximum lift coefficient of the basic airfoil was 1.3. A lift coefficient of 1.71 was obtained with a section flow coefficient of 0.0008, and a maximum lift coefficient of 1.78 was obtained with a section flow coefficient of 0.0014. It was found that for a given lift coefficient a very low power would be required for suction, provided a suitable permeability and arrangement of porous material were employed. The flow resistance characteristics of some porous materials that might be used to provide such a surface are given.