Full-Scale Wind-Tunnel Investigation of Wing Cooling Ducts, Special Report
This is a 1938 NACA special report on full-scale wind-tunnel tests of wing cooling ducts, issued by the National Advisory Committee for Aeronautics for aeronautical engineers and researchers. Its photographs show aircraft wing surfaces with rectangular intake and outlet openings, photographed close up and from below in test setups, offering a designer a plain reference for how flush duct openings sit within curved aerofoil skins.





