Rotating detonation engines (RDEs) are an advanced propulsion technology utilizing detonation combustion. RDEs have shown significant potential for substantially enhancing the performance of conventional propulsion systems due to their inherent advantages such as rapid energy release, high thermal efficiency, and a compact reaction zone. Based on these strengths, we conducted experimental investigations of a disk-shaped rotating detonation engine to examine the influences of the oxygen content on the operation characteristics of the engine. The results demonstrate that oxygen enrichment significantly altered the evolution process of rotating detonation waves (RDWs), with dual-wave modes exhibiting higher initiation probability under oxygen-enriched conditions. The results of a quantitative analysis revealed that increasing oxygen content of 21% to 30% increased the velocity of the detonation wave by 11-17% for a single-wave mode and 5-7% for a dual-wave mode. The results of parametric studies demonstrate that increased mass flow rate enhanced the propagating stability of rotating detonation waves, which reduced fluctuations in their parameters. Increasing oxygen content conversely decreased the RDWs’ propagation stability, particularly at low flow rates in single-wave mode. Increasing the oxygen content facilitated the formation of multiple waves, which reduced critical mass flow rate as well as the lean limit of the equivalent ratio for multi-wave modes. Furthermore, oxygen enrichment markedly diminished the lean limit of engine’s operation equivalent ratio, which broadened the stable operating envelope. In contrast with pure air, the lean operation limit of equivalent ratio declined by roughly 25%-59% under oxygen-enriched air conditions. The results of this study demonstrate that oxygen content critically influences the RDWs’ propagation mode in disk-shaped structure as well as the parameters of the detonation waves and the engine’s operation envelope of the engine. These findings offer a deeper understanding of rotating detonation wave propagation and establish a foundation for advancing rotating detonation combustion applications.
Xia et al. (Tue,) studied this question.