On detonation initiation by a temperature gradient for a detailed chemical reaction models

The evolution from a temperature gradient to a detonation is investigated for combustion mixture whose chemistry is governed by a detailed chemical kinetics. We show that a detailed chemical reaction model has a profound effect on the spontaneous wave concept for detonation initiation by a gradient of reactivity. The evolution to detonation due to a temperature gradient is considered for hydrogen–oxygen and hydrogen–air mixtures at different initial pressures. It is shown that the minimal length of the temperature gradient for which a detonation can be ignited is much larger than that predicted from a one-step chemical model.

► We study detonation initiation by temperature gradient for detailed chemical models.
► Detailed chemical models have a profound effect on the spontaneous wave concept.
► Initiating detonation by temperature gradient differs from one-step model.
► In real fuels DDT can not be initiated by temperature gradient.