在高度H=1 mm,宽度W=20 mm的狭缝内,实验研究了不同初始压力( P0=10~40 kPa)下化学恰当比的C2 H4/O2预混气的爆轰传播特性。采用烟迹法记录爆轰胞格结构,同时采用高速摄影捕捉火焰面。实验结果表明,随着初始压力降低,爆轰波的化学反应诱导区距离增大,壁面条件(如摩擦、导热)的影响增强,导致火焰传播的速度震荡加剧,爆轰波传播从多头模式向单头模式过渡,并可出现多次起爆或者熄爆等复杂现象。此外,稳定自持传播爆轰波的速度亏损会随初始压力降低而增大,但详细规律还需进一步研究。%Influence of different initial pressures ( P0 =10~40 kPa) on detonation propagation of stoichiometric C2 H4/O2 mixtures was experimentally studied in a narrow gap with 1-mm-height and 20-mm-width. The soot film was utilized to record the detonation cell structure, and the high-speed cinematography was used to capture the flame. It can be found that the chemical reaction induction zone length of detonation increases and the influence of wall condition ( such as friction and heat conduction) strengthens with the decrease of initial pressure, hence, the flame velocity fluctuation is intensified. And the detonation propagation transits from multi-head mode to single-head mode, which even can appear multiple detonation initiation or detonation failure phenomena. In addition, the velocity deficit of self-sustained detonation wave becomes larger with the decrease of initial pressure, however, the detailed variation rule needs a further study.
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