A Low-density Wind-tunnel Study of Shock-wave Structure and Relaxation Phenomena in Gases

Note presenting an investigation of the profiles and thicknesses of normal shock waves of moderate strength in terms of the variation of the equilibrium temperature of an insulated transverse cylinder in free-molecule flow. The shock waves were produced in a steady state in the jet of a low-density wind tunnel, at initial Mach numbers of 1.72 and 1.82 in helium and 1.78, 1.85, 1.90, 1.98, 3.70, and 3.91 in air. Results regarding the free-molecule probe response in a uniform stream, operation of normal shock holders, normal-shock-wave profiles, shock-wave thicknesses, evidence of wire-size effect on shock-wave profile, and the potential of experimental error are provided.