横向射流影响缓燃向爆震转捩过程的试验研究

为探究横向射流对缓燃转爆震过程的影响，在高为20 mm，深为6 mm，总长为810 mm的矩形通道内进行了横向射流加速起爆的单爆试验。采用甲烷和氧气的预混气为反应物，点火源为点火能量为50 mJ的弱火花塞点火。垂直于主流的横向喷射孔径为1 mm，喷射介质为与反应物同浓度的混气。试验主要研究射流延迟时间、射流位置、射流数量和射流分布形式对起爆特性的影响。结果显示，射流各喷射位置下均存在相应的最佳射流延迟喷射时间使得预混气的起爆时间最短。射流位置分别位于距点火区90、270 mm处的平行双射流和90、180 mm处的交错射流均具有最短的起爆时间，约为1 ms。

Experimental study of effects of fluidic obstacle parameters on deflagration-to-detonation transition

To investigate the effect of jet in cross flow on the process of Deflagration-to-Detonation Transition (DDT), an single-shot detonation experiment is conducted in a rectangular channel with a height of 20 mm, a depth of 6 mm, and a total length of 810 mm. The premixed methane/oxygen mixture is the reactant, which is ignited by a 50 mJ spark plug. The diameter of the injector of jet in cross flow is 1 mm, and the injection gas is the same concentration premixed mixture. The effect of the jet delay time, the jet location, the quantity and jet distribution pattern on detonation initiation are studied by a series of tests. The results show that there exits at various injection locations the corresponding optimal jet delay time to minimize the DDT time. The DDT time of the parallel double jets located 90 and 270 mm away from the ignition zone and the staggered jets located at 90 and 180 mm away from the ignition zone is the shortest, about 1 ms.