Aerodynamic Characteristics of Airfoil with Thin Leading-Edge at Low Reynolds Numbers

Abstract

The aerodynamic characteristics of the thick stream-lined airfoil were studied by conducting the wind tunnel tests at Reynolds number ranging between 3×10³ and 7×10⁴. The Reynolds number based on the wing chord of insect wings is less than 1×10⁴ and that of bird wings is more than 1×10⁴. The aerodynamic characteristics of airfoils are strongly affected by the leading-edge thinness. The thin leading-edge which was obtained by attaching the thin flat plate at the rounded leading-edge was effective at lower Reynolds numbers. However the stream-lined airfoil with rounded leading-edge performed well at higher Reynolds numbers. The course of this phenomenon was the laminar separation bubble generated on the upper surface of the wing. The Reynolds number effects on the leading-edge profiles for the thick stream-lined airfoils were cleared in this paper.