Drag and Cooling with Various Forms of Cowling for a "Whirlwind" Radial Air-Cooled Engine I
This NACA technical report from 1930, issued by the National Advisory Committee for Aeronautics and preserved through the NASA Technical Reports Server, presents wind-tunnel test results comparing drag and engine cooling for different engine cowlings on a Whirlwind radial air-cooled aircraft engine. Its plates are photographs of model and full-scale cowl shapes, mounted on the engine and photographed in a test setting, for aircraft engineers. A designer could take from them the smooth, tapered, rounded nose forms and the close-up views of exposed radial cylinders and propeller hubs as references for streamlined housings.
