Tests of N.A.C.A. airfoils in the variable-density wind tunnel Series 24
This is a 1932 NACA technical report from the NASA Technical Reports Server, recording wind tunnel tests of airfoil sections in the variable-density wind tunnel for aeronautical engineers and researchers. The pictures are engineering line graphs plotting lift-to-drag ratio, centre of pressure, and lift and drag coefficients against angle of attack, drawn as black curves with circled and crossed data points on gridded paper, with one page rotated sideways showing a test data sheet. A designer might take from them the clean, restrained grid-and-curve vocabulary of early aerodynamic data charts.
