Ground Effect - Theory and Practice
This is a 1937 NASA technical report on ground effect, the change in airfoil lift and drag near a surface, compiled from theory and wind-tunnel practice for aeronautical engineers. The pictures are plain engineering line graphs and diagrams: a conformal-mapping plane sketch, curves of pressure coefficient against angle and chord ratio, and lift curves for a flat plate at several heights, offering a designer a clear reference for how a nearby surface bends performance curves.
