论文标题
不稳定性在横向紧张的爆炸波的极限上的作用
Role of instability on the limits of laterally strained detonation waves
论文作者
论文摘要
本工作研究了不稳定性和扩散现象在控制受侧向应变速率的爆炸限制中的作用。在具有不同水平的细胞不稳定性水平的烃 - 氧混合物中进行了实验。在Radulescu \＆Borzou（2018）和Xiao \＆Radulescu（2020）的最新作品之后，这些爆炸在具有指数扩大的横截面的通道中传播。在宏观尺度上获得了稳定的爆炸波，其近限制反应区结构的特征是显着的未反应气口。这些口袋的湍流火焰燃烧速度被评估为30 m/s至70 m/s，比理论层流的值大于2至7。对于所有测试的混合物，特征性$ d-k $关系的所有混合物，将爆炸的平均繁殖速度与后期的流动率相关联，并且与实验相关，并与实验直接相关，并与实验相关联，并且是从实验中获得的。详细的化学动力学。结果表明，实验和理论预测之间的出发程度随爆炸不稳定性水平显着增加。与层流ZnD波相比，较不稳定的爆炸比较稳定的爆炸更加引爆得多，其限制差异速率和最大速度缺陷大大较大。这种增强性随着爆炸不稳定性的增强性可以体现在全球能量释放的显着增强速率中，对于更不稳定的爆炸而言，点火的热特征显着抑制。人们发现，这种全球增强的燃烧机制是通过不反应气口湍流燃烧的湍流扩散燃烧来实现的，从而大大缩短了特征反应区的长度。
The present work examines the role of instability and diffusive phenomena in controlling the limits of detonations subject to lateral strain rates. Experiments were conducted in hydrocarbon-oxygen mixtures with varying levels of cellular instability. These detonations were propagated in channels with exponentially enlarging cross-sections, following the recent works of Radulescu \& Borzou (2018) and Xiao \& Radulescu (2020). Steady detonation waves were obtained at the macro-scale, with the near-limit reaction zone structures characterized by significant unreacted gas pockets. The turbulent flame burning velocity of these pockets was evaluated to be 30 m/s to 70 m/s, which is larger than the theoretical laminar value by a factor of 2 to 7. For all the mixtures tested, the characteristic $D-K$ relationships, relating the detonation mean propagation speed with lateral flow divergence, were obtained directly from experiments and as well from the generalized ZND model with lateral strain rates using detailed chemical kinetics. The results showed that the degree of departure between experiments and the theoretical predictions increases significantly with the detonation instability level. As compared to the laminar ZND wave, the more unstable detonations are much more detonable than the more stable detonations, with substantially larger limiting divergence rates and maximum velocity deficits. Such enhanced detonability with detonation instability can be manifested in the significantly enhanced global rates of energy release with the notably suppressed thermal character of ignition for the more unstable detonations. This globally enhanced burning mechanism is found to be realized by the intensified auto-ignition assisted by the turbulent diffusive burning of the unreacted gas pockets, substantially shortening the characteristic reaction zone lengths.
