Principles involved in the cooling of a finned and baffled cylinder
A 1938 NACA technical report from the NASA Technical Reports Server, written for aeronautical engineers, on how heat leaves a finned and baffled aircraft engine cylinder. Its pictures are plain engineering graphs of heat-transfer coefficient against fin spacing and fin thickness, with laminar, transition and turbulent flow curves and log-scale data plots. A designer could take from them only the visual language of technical charts: thin grid lines, labelled curves in legend boxes, and sparse black-and-white line work.





