Investigation on the effect of geometric configuration on the flow field morphology and propulsive performance of oblique detonation combustor

Abstract

This study conducts numerical simulations of Oblique Detonation Wave (ODW) flow fields in confined spaces, focusing on how variations in the combustor’s initial wedge angle and expansion angle affect flow field morphology and propulsion performance. A new initiation mechanism induced by small wedge angles has been identified, enabling the transition from shock-induced combustion to oblique detonation combustion. A simplified model was developed to predict the position and height of the Mach Stem (MS) in the detonation flow field, providing insights into the regulation of the transition from normal detonation combustion to oblique detonation combustion. The study confirms that the incident wave’s intensity and the separation zone's geometric parameters are the two critical factors governing MS dynamics. Furthermore, the downstream parameter variations associated with shock-induced combustion, oblique detonation combustion, and normal detonation combustion are analyzed, explaining the relationship between propulsion performance and flow field structure. Adjusting wall curvature to reduce detonation wave overdrive is found to improve the combustor’s propulsion performance significantly. This research establishes a clear link between detonation flow fields and combustor geometry, offering valuable insights into the dynamic regulation of Oblique Detonation Engines (ODEs) under near-realistic operating conditions.