流体障碍物对爆震燃烧起爆性能影响的实验研究

Experimental Study for Effects of Fluidic Obstacles on Detonation Initiation Performance

关键词:  冷态流体障碍物  热态流体障碍物  起爆距离  喷射孔径

Key words:  Non-reacting fluidic obstacles  Hot fluidic obstacles  Detonation transition distance  Injection diameter

摘要:

为研究流体障碍物对于缓燃火焰向爆震波转变特性的影响，用乙烯和40%的富氧空气作为燃料和氧化剂，在6mm方形爆震管中进行了爆震燃烧实验。将带流体障碍物的爆震管与常规光滑爆震管起爆性能进行了对比，并首次提出了用热态流体障碍物加速起爆的方法。实验结果表明，在恰当的喷射孔径下，流体障碍物能够有效地加速爆震波的起始。对于6mm方形爆震管，通入1mm直径的冷态和热态流体障碍物均能够明显地加速起爆，分别使起爆距离缩短24%和15%；2mm热态流体障碍物没有明显的加速起爆作用，而2mm冷态流体障碍物甚至阻碍了火焰的传播。在相同的射流尺寸下，相比于传统的冷态流体障碍物，热态流体障碍物有更好的爆震加速起始增益效果。

Abstract:

To investigate the impact of the fluidic obstacles on the deflagration to detonation transition (DDT) process，experiments were conducted in a 6mm square tube，using ethylene and 40% oxygen enriched air as fuel and oxidant，respectively. The detonation performance of the tube with fluidic obstacles was compared with that of the smooth tube，and the method of accelerating detonation using hot fluidic obstacles was first proposed. The results show that fluidic obstacles can effectively accelerate detonation initiation at proper jet diameter. For the 6mm square tube，injecting 1mm diameter non-reacting/hot gas fluidic obstacle can both remarkably accelerate detonation initiation，shortening 15% and 24% DDT distance，respectively. However，the 2mm diameter hot fluidic obstacle almost has no positive effect，even the 2mm non-reacting fluidic obstacles impedes the flame propagation. Therefore，the hot fluidic obstacles enhance detonation better than the conventional non-reacting fluidic obstacles at the same jet diameter.