Low Drag Airfoil Design Utilizing Passive Laminar Flow and Coupled Diffusion Control Techniques

摘要

A two-dimensional high chord Reynolds number passive laminar airfoil was designed for a C sub l = 0.73 at a M at infinity = 0.6 and Re sub c = 4 times 10 to the 7th power providing an extremely high L/D = 240. This laminar airfoil design concept integrates passive laminar flow stabilization, by pressure gradient shaping, with active diffusion control techniques on the airfoil trailing edge. A discussion of the airfoil design concept and the predicted performance is presented. Full scale Reynolds number passive laminar flow/transition experiments defining maximum transition Reynolds number and real flow environment influence on transition are presented. Examination of wind tunnel scaling influences and real flow environment effects on the ATC/laminar airfoil performance are discussed and summarized for typical low turbulence tunnels. (Author)