Laminar Separation, Transition, and Turbulent Reattachment near the Leading Edge of Airfoils

The laminar separation, transition, and turbulent reattachment near the leading edge of a cylindrical noseconstant thickness airfoil model were investigated using a low-turbulence, low-speed smoke wind tunnel. The locations of separation, transition, and reattachment were obtained from smoke flow photographs and surface oil flow techniques for chord Reynolds numbers from about 150,000 to 470,000. These visual data combined with static pressure distributions delineate the effects of angle of attack, flap deflection angle, and chord Reynolds number on the separation bubble characteristics. The data concerning the length of the laminar and turbulent portions of the bubble agree with the empirical prediction methods for short bubbles.