Vibration-dissociation coupling effects on shock standoff distances

Shock standoff distances for a sphere in intermediate hypersonic flows (2.5- 4.5 km/s) are calculated to investigate the effect of vibration-dissociation coupling on the nonequilibrium thermochemical state in the shock layer. The vibration-dissociation coupling effect in the two-temperature model of Park is examined through 1) changing the definition of the controlling temperature of dissociation reactions, and 2) changing the amount of disposal of the energy in preferential dissociation. It is found that the shock standoff distance is insensitive to both of 1) and 2) in this flight regime. It is also found that the use of the CVDV model has a minor influence on the shock standoff distance.