The "Magnus effect" - the principle of the Flettner rotor
This is a 1925 technical report from NASA's Technical Reports Server, a scanned aeronautical paper explaining the Magnus effect behind the Flettner rotor, written in line-drawing diagrams for engineers and students of fluid flow. The pictures are plain black-line schematics of streamlines around cylinders, vortex shedding, a spinning tennis ball's curved path, and constriction flows, offering a designer clean, diagrammatic flow lines and vortex curls as graphic motifs.
