Induction and transient times in chemical reactions: Application to O₂ dissociation Available to Purchase

An analysis of relaxation phenomena in diatomic molecules, based on a harmonic oscillator master equation formalism, can accurately predict induction times for O₂ dissociation in shock tubes, in the temperature range 2850° to 18 000°K, using measured vibrational relaxation times. In this case, the induction times are the direct result of relaxation of lower vibrational states prior to chemical reaction. Transient times for chemical reactions in temperature jump or shock tube experiments are shown to depend on the magnitude of the difference between initial and final temperatures. The phenomenological rate expression is valid for times greater than the transient times for large temperature jumps, and for practically all times for small temperature jumps.