Reduction of turbulence in wind tunnels
A 1931 NASA technical report on reducing turbulence in wind tunnels, published as a numbered series of engineering diagrams for aeronautical researchers. The pictures are plain line drawings of wind tunnel cross-sections numbered No. 1 through No. 6, showing a honeycomb flow straightener, a wire screen, the working section and an up and down stream layout with a scale bar in feet. A designer could take from them the clean, diagrammatic vocabulary of technical drawing, with thin labelled leader lines, dashed flow paths and sequenced panels.
