The structure of detonation waves propagating through the annular channel of an optically accessible non-premixed rotating detonation engine (RDE) are investigated using mid-infrared imaging. The RDE is operated on hydrogen–air mixtures for a range of air mass flow rates and equivalence ratios. Instantaneous images of the radiation intensity from water vapor are acquired using a mid-infrared camera and a band-pass filter (2.890 ± 0.033 µm). The instantaneous mid-infrared images reveal the stochastic nature of the detonation wave structure, position and angle of oblique and reflected shock waves, presence of shear layer separating products from the previous and current cycles, and extent of mixing between the reactants and products in the reactant fill zone in front of the detonation wave. The images show negligible signal directly in front of the detonation waves suggesting that there is minimal mixing between the reactants and products from the previous cycle ahead of the detonation wave for most operating conditions. The mid-infrared images provide insights useful for improving fundamental understanding of the detonation structure in RDEs and benchmark data for evaluating modeling and simulation results of RDEs.

使用中红外成像技术研究了在光学可访问的非预混旋转爆轰发动机（RDE）的环形通道中传播的爆轰波的结构。RDE在氢气-空气混合物上运行，以实现一定范围的空气质量流量和当量比。使用中红外摄像头和带通滤光片（2.890±0.033 µm），可以获取水蒸气辐射强度的瞬时图像。瞬时中红外图像显示了爆炸波结构的随机性质，倾斜和反射冲击波的位置和角度，剪切层的存在，该产物将先前循环和当前循环分离开来，以及反应物和产物在反应釜中的混合程度。爆炸波前面的反应物填充区。图像在爆炸波前直接显示可忽略的信号，这表明在大多数操作条件下，在爆炸波之前的前一个循环中，反应物和产物之间的混合极少。中红外图像提供了有用的见解，可用于增进对RDE爆轰结构的基本了解，以及用于评估RDE建模和仿真结果的基准数据。