Domains and Boundaries of Pseudo-Stationary Oblique Shock-Wave Reflections in Air

摘要

The reflection of oblique waves in air in pseudo-stationary flow was investigated analytically and numerically. The transition boundaries between the four types of shock wave reflection (regular RR, single Mach SMR, complex Mach CMR and double Mach DMR) were established up to M sub s = 20 for both perfect and imperfect air in thermodynamic equilibrium (rotation-vibration coupling, vibrational excitation, dissociation, electronic excitation and ionization). In addition, an analysis was made for perfect gases with differing gamma in order to clarify the effects of the specific heat ratio gamma on the shock wave configurations. It was verified that the reflected wave angle omega' was a very sensitive function of gamma and a decrease in gamma lowered the value of omega' significantly and even shifted the value of omega' towards negative values under certain conditions of Mach reflection. This phenomenon occurred in a perfect gas with gamma less than 1.4 and in imperfect air. Results show no crossings of transition lines and removes the conjecture of possible triple Mach reflection.