Numerical investigation of the propagation characteristics of H2-F2-Air fueled rotating detonation waves

The incorporation of fluorine (F 2 ) into hydrogen-air (H 2 /Air) mixtures presents a novel approach to enhancing the performance of rotating detonation engines (RDEs). This study systematically investigates the effects of F 2 concentration and inlet mass flow rate on rotating detonation wave (RDW) propagation using two-dimensional numerical simulations, providing the first comprehensive analysis of F 2 as an oxidizing additive in regulating detonation performance, propagation stability, and heat release dynamics in RDEs. The results indicate that when F 2 concentration is below 1%, the flow field primarily exhibits a stable single-wave propagation mode. As F 2 concentration increases, RDW performance initially improves but then deteriorates, reaching its optimal state at 0.8% F 2 . When F 2 concentration exceeds 1%, the coupled effects of F 2 concentration and inlet mass flow rate induce a transition from single-wave to multi-wave propagation modes. While a higher inlet mass flow rate promotes increased wave numbers, it also intensifies wave-wave interactions. With further increases in F 2 concentration, the enhanced heat release leads to intensified local deflagration, frequent hotspot formation, and wave collisions, ultimately degrading RDW performance and destabilizing the multi-wave flow field. Moreover, excessive HF formation is identified as a critical driver of enhanced deflagration, hotspot generation, and the disruption of multi-wave stability. These findings provide a theoretical foundation for integrating F 2 additives into H 2 /Air-based RDE systems.