Vibrational Energy Transfer in Diatomic Gas Mixtures

Abstract

Flow-tube experiments on vibrational energy transfer from N2* to CO and NO are described. A primary flow of N2 was vibrationally excited by an S-band microwave discharge and mixed with either cold CO or NO. The first overtone band radiation from the heteronuclear molecules was spectrally resolved at selected downstream stations, and the data were compared with an analytical model computed for different number density distributions. Flow-tube measurements of rotationally cold, but vibrationally excited, N2*–CO and N2*–NO systems indicate that at steady-state conditions, (1) the CO and NO are not in vibrational equilibrium, and (2) the nonequilibrium populations of the molecules cannot be predicted by the model postulated by Treanor et al.