AIRFOIL SECTION CHARACTERISTICS AT A LOW-REYNOLDS-NUMBER

The aerodynamic characteristics of airfoils operating at Re = 4 x 10(3 ) were examined, varying the parameters related to the airfoil shape s uch as thickness, camber and roughness. Airfoils with good aerodynamic performance at this Re have the following shape characteristics: (1) they are thinner than airfoils for higher Re numbers, (2) they have a sharp lending edge, and (3) they have a camber of about five percent w ith its maximum camber at about mid-chord. The characteristics of airf oils are strongly affected by leading edge vortices. The measured two- dimensional airfoil characteristics indicate that the planform, which greatly affects the flight performance of the the three-dimensional wi ng at high Reynolds numbers, has little effect on the flight performan ce at this Reynolds number.