Investigating the flow characteristics and thermodynamic performance of curved detonation waves

Abstract

Oblique detonation waves (ODWs) are induced by oblique shock waves (OSWs) and hold significant research value for air-breathing ramjet engines due to their high thermodynamic efficiency and specific impulse. In this research, detonation is induced using a curved shock wave (CSW) that provides greater flexibility compared to an OSW. Curved detonation waves (CDWs) are classified into two categories based on the curvature of the CSW: positive-curvature curved detonation waves (PC-CDWs) and negative-curvature curved detonation waves (NC-CDWs). We conduct a numerical investigation of the flow characteristics and potential thermodynamic performance in curved detonation waves (CDWs) by solving the two-dimensional multi-species Euler equations with a detailed hydrogen combustion mechanism. In contrast to ODWs, we observe continuous compression and expansion effects in the flow fields of PC-CDWs and NC-CDWs, respectively. Continuous compression shortens the initiation length of the detonation wave and intensifies the compression wave preceding the combustion front, whereas continuous expansion produces the opposite outcome. Changes in the curvature of the CSW result in alterations to the flow characteristics of the CDW. These flow characteristic changes are manifested in their thermodynamic and propulsion-related performance. More specifically, a lower overdrive of the detonation wave corresponds to a reduced loss in total pressure.