柔性障碍物对甲烷空气爆炸波激励作用的实验研究

为研究柔性障碍物对甲烷空气爆炸波的激励效应，采用双向拉伸聚丙烯（biaxially oriented polypropylene, BOPP）薄膜作为柔性障碍物将管道内甲烷空气预混气体与空气隔开，对比障碍物前后火焰、激波变化，分析膜状柔性障碍物激励效应的机理。实验结果表明:这种具有一定承压能力的柔性障碍物对甲烷爆炸波产生的激励效应不可忽视，在膜片破裂前产生多次激波反射过程，可诱导湍流火焰形成，促使膜前爆炸压力提高，膜片破裂后，火焰在伴流作用下传播速度突增，并加速逐渐逼近前驱冲击波，致使膜后爆炸压力大幅提高；激励效应可使膜片前后最大爆炸压力相差5倍，火焰速度相差7倍；另外在膜片位置2.5 m后增设一道膜片，可增强这种激励效应，而增加膜片的实质是使激波火焰相互作用的次数增加。

Experimental study on incentive effect of flexible obstacle on methane-air explosion wave

In order to study the incentive effect of flexible obstacles on methane-air explosion waves, a biaxially oriented polypropylene ( BOPP) film was used as a flexible obstacle to separate the methane-air premixed gas from the air in the pipeline, the difference of the flame and shock wave before and after they propagated through the obstacle was compared, and the mechanism of the incentive effect of the flexible membrane obstacle was analyzed. The experimental results show that the incentive effect of this flexible obstacle with certain pressure-bearing capacity on the methane explosion wave cannot be ignored. Multiple reflections of shock wave before the rupture of the flexible membrane can result in the formation of turbulent flame, and thus greatly increase the explosion pressure. After the rupture of the flexible membrane, the velocity of the flame increases suddenly under the action of the concomitant flow and approaches the shock wave, resulting in a great increase in the explosion pressure behind the membrane. The experimental data show that the difference in the maximum explosion pressure between the locations before and after the membrane is five times and the corresponding difference of flame velocity is seven times. In addition, it is found that the incentive effect can be enhanced by adding an additional membrane after the original one with a prescribed distance and the essential role of the additional membrane is to increase the interaction numbers between the shock wave and the flame.