Separation of Gas Mixtures in a Supersonic Jet

Abstract

In 1954, E. W. Becker and co-workers in Marburg, Germany, discovered that large composition gradients existed in the supersonic jet generated by expanding a gas mixture through a Laval nozzle. Further experimental observations of this effect are presented for the mixtures A–N2, O2–N2, and N2–C2H4, showing characteristics of the phenomenon not previously reported. A quantitative theory based on free-molecule kinetics is suggested, and gives reasonable agreement with the experimental results in several respects.