Pressure gain combustion in the form of continuous detonations can provide a significant increase in the efficiency of a variety of propulsion and energy conversion devices. In this regard, rotating detonation engines (RDEs) that utilize an azimuthally-moving detonation wave in annular systems are increasingly seen as a viable approach to realizing pressure gain combustion. However, practical RDEs that employ non-premixed fuel and oxidizer injection need to minimize losses through a number of mechanisms, including turbulence-induced shock-front variations, incomplete fuel-air mixing, and premature deflagration. In this study, a canonical stratified detonation configuration is used to understand the impact of preburning on detonation efficiency. It was found that heat release ahead of the detonation wave leads to weaker shock fronts, delayed combustion of partially-oxidized fuel-air mixture, and non-compact heat release. Furthermore, large variations in wave speeds were observed, which is consistent with wave behavior in full-scale RDEs. Peak pressures in the compression region or near triple points were considerably lower than the theoretically-predicted values for ideal detonations. Analysis of the detonation structure indicates that this deflagration process is parasitic in nature, reducing the detonation efficiency but also leading to heat release far behind the wave that cannot directly strengthen the shock wave. This parasitic combustion leads to commensal combustion (heat release far downstream of the wave), indicating that it is the root cause of combustion efficiency losses.

连续爆震形式的压力增益燃烧可以显着提高各种推进和能量转换装置的效率。在这方面，在环形系统中利用方位角移动的爆震波的旋转爆震发动机（RDE）越来越被视为实现压力增益燃烧的可行方法。但是，采用非预混合燃料和氧化剂喷射的实际RDE需要通过多种机制来最大程度地减少损失，这些机制包括湍流引起的激波前变化，不完全的燃料-空气混合和过早爆燃。在这项研究中，使用规范的分层起爆构型来了解预燃对起爆效率的影响。已经发现，在爆炸波之前释放的热量会导致较弱的冲击波前沿，延迟了部分氧化的燃料-空气混合物的燃烧，并散发了非紧凑的热量。此外，观察到波速的较大变化，这与全尺寸RDE中的波行为一致。压缩区域或三重点附近的峰值压力大大低于理想爆轰的理论预测值。爆震结构分析表明，这种爆燃过程本质上是寄生的，降低了爆震效率，但还导致热量释放远远超出了不能直接增强冲击波的波后。这种寄生燃烧导致共燃（热量在波的下游释放），表明这是燃烧效率损失的根本原因。观察到波速的大变化，这与全尺寸RDE中的波行为一致。压缩区域或三重点附近的峰值压力大大低于理想爆轰的理论预测值。爆震结构分析表明，这种爆燃过程本质上是寄生的，降低了爆震效率，但还导致热量释放远远超出了不能直接增强冲击波的波后。这种寄生燃烧导致共燃（热量在波的下游释放），表明这是燃烧效率损失的根本原因。观察到波速的大变化，这与全尺寸RDE中的波行为一致。压缩区域或三重点附近的峰值压力大大低于理想爆轰的理论预测值。爆震结构分析表明，这种爆燃过程本质上是寄生的，降低了爆震效率，但还导致热量释放远远超出了不能直接增强冲击波的波后。这种寄生燃烧导致共燃（热量在波的下游释放），表明这是燃烧效率损失的根本原因。压缩区域或三重点附近的峰值压力大大低于理想爆轰的理论预测值。爆震结构分析表明，这种爆燃过程本质上是寄生的，降低了爆震效率，但还导致热量释放远远超出了不能直接增强冲击波的波后。这种寄生燃烧导致共燃（热量在波的下游释放），表明这是燃烧效率损失的根本原因。压缩区域或三重点附近的峰值压力大大低于理想爆轰的理论预测值。爆震结构分析表明，这种爆燃过程本质上是寄生的，降低了爆震效率，但还导致热量释放远远超出了不能直接增强冲击波的波后。这种寄生燃烧导致共燃（热量在波的下游释放），表明这是燃烧效率损失的根本原因。