Visualization and analysis of bow shocks in a superorbital expansion tube

Abstract

Reported here are the first optical measurements of very high enthalpy flows in a superorbital expansion tube. Holographic interferograms have been recorded of air flows at a velocity of 11 kms -1 around a variety of models.The ratios of densities across the shocks have been calculated from measurement of the shock shapes displayed in the interferograms. These results have been compared with predictions based on assumptions of frozen and equilibrium flow.