Numerical study of detonation instability for a two-step kinetics model

چکیده مقاله

The stability of CJ detonations has been investigated numerically with a two-step kinetics model.The reaction model consists of a non-heat release induction step, followed by an exothermic step. Both steps are governed by the Arrhenius kinetics model. The e ect of activation energies associated with these steps on the detonation front behavior has been studied. This study was arranged in two stages. At each stage, one of the activation energies was kept constant and the other one was changed. In the steady detonation structure, the activation energies of the rst and second steps (Ea1;Ea2) control the induction and reaction lengths, respectively. Increasing Ea1
(for a xed Ea2) increases induction length and destabilizes a detonation, the same behavior as a one-step model. Increasing Ea2 rst increases reaction length and has a stabilizing e ect (i.e., the amplitude of oscillation decreases). Further increasing Ea2 has a destabilizing e ect. The present study shows that the ratio of the reaction length to the induction length characterizes general features of detonation stability.