The Performance of a Depalma Roots-type Supercharger
This is a 1936 NACA technical report, issued through NASA's technical reports server, on the performance testing of a Depalma Roots-type supercharger for aircraft engines, written for engineers and researchers. The pictures are plain black-and-white engineering drawings and photographs: an exploded view and test rig photo of the supercharger, a sectional drawing of a clearance gauge with a scale, and graphs plotting pressure difference against rotor speed and air flow. A designer might take from them the clean, technical line-drawing style and the way graph axes and labelled sectional views are set out.
