A High-Performance Ultraviolet Optical Sensing System for Rotating Detonation Extreme Combustion

Extreme combustion features strong unsteadiness, heterogeneity and multi-physics coupling, which is of great significance for advanced propulsion systems. High-performance sensing of such extreme combustion flow fields is critical to revealing physical mechanisms and capturing fine flow structures. However, it faces severe challenges: rich multi-band spectral characteristics require multi-spectral observation; ultra-transient processes demand high-frequency imaging; and high-performance photoelectric enhancement is necessary under short gate width and high frame rates. To solve these problems, this study developed a high-performance ultraviolet optical sensing system (HUOSS), which achieves megahertz-level imaging at a 1608 × 1104 full-frame resolution and provides a 10⁷ electron gain in the ultraviolet band. The HUOSS has been applied to chemiluminescence sensing of a hydrogen/ammonia-air rotating detonation as a representative extreme combustion system. Based on the analysis of representative influencing factors (e.g., the transmission characteristic of the bandpass filter and the intensifier gate width) in the HUOSS, the filter transmission loss and its influence on the gate width settings have been revealed. From the chemiluminescence sensing images captured in the experiments, the fine structure and evolution of detonation waves have been clearly identified, verifying the high-speed imaging capability. Furthermore, simultaneous OH* and NH* multi-spectral observation has been realized, and the effects of ammonia addition have been analyzed, validating the multi-spectral diagnostic capacity of the system. This study provides an effective diagnostic method for extreme transient combustion research, and comprehensively verified the multi-spectral, extremely transient and high signal-to-noise ratio sensing capabilities of this system.