Detonation structures behind oblique shocks

TLDR

Time‑dependent numerical simulations were employed to study detonation structures generated by wedge‑induced oblique shocks in hydrogen–oxygen–nitrogen mixtures. The simulations reveal a stable, multidimensional detonation structure consisting of a nonreactive oblique shock, an induction zone, a set of deflagration waves, and a reactive shock tightly coupled to energy release; the structure remains steady on the wedge when the post‑shock flow is fully supersonic, but detaches and moves upstream when part of the flow becomes subsonic.

Abstract

Detonation structures generated by wedge-induced, oblique shocks in hydrogen–oxygen–nitrogen mixtures were investigated by time-dependent numerical simulations. The simulations show a multidimensional detonation structure consisting of the following elements: (1) a nonreactive, oblique shock, (2) an induction zone, (3) a set of deflagration waves, and (4) a ‘‘reactive shock,’’ in which the shock front is closely coupled with the energy release. In a wide range of flow and mixture conditions, this structure is stable and very resilient to disturbances in the flow. The entire detonation structure is steady on the wedge when the flow behind the structure is completely supersonic. If a part of the flow behind the structure is subsonic, the entire structure may become detached from the wedge and move upstream continuously.