The formation and development of oblique detonation wave with different chemical reaction models

Abstract In this paper, we investigate the formation and development characteristics of oblique detonation wave in stoichiometric hydrogen-oxygen mixtures diluted with argon using Euler equations coupled with the 19-step or 34-step chemical reaction model. The novelty of this work lies in the study of differences in the characteristics of the initiation region and the formation processes of oblique detonation by different chemical kinetic processes. The formation processes of radicals in the induction region and heat release region for the oblique detonation flow field are emphatically analyzed, and the differences in the sensitivity on the key chemical reaction channels to radicals are also discussed. The results show that under the action of 19-step mechanism, the oblique detonation forms relatively early, the wave morphology of the flow field is complex, and the type of the initiation region is abrupt transition. While for the 34-step mechanism, the structure of flow field is simple with smooth transition type. The existence of transverse wave in the mainstream region contributes a lot to the formation of a sonic region and the abrupt transition structure. The chemical kinetic process directly affects the flow field structure of oblique detonation, and H2O2 plays an important role on triggering and accelerating the exothermic process. The radicals of H, O and H2O2 have different properties in different chemical reaction models.