障碍物对油气－空气混合气体泄压爆炸火焰传播特性影响

摘要

In order to investigate the effect of obstacles on the flame propagation characteristics of vented explosion by gaso -line-air mixture, a series of contrast experiments were carried out under the conditions of obstacles with different amount .The schlieren and high-speed camera were applied to record the flame propagation process , and the influence laws of obstacles on the flame shape , flame front location and flame speed were studied .The results showed that the cylindrical obstacles can cause the wrinkle and bending deformation of flame shape , induce the transition from laminar flame to turbulent flame , and accelerate the flame propagation , with significant effect on the initial propagation shape of gasoline -air vented explosion flame.The maximum distance of flame front spreading away from the ignition source increases with the increasing amount of obstacles , while the time to reach the farthest distance becomes shorter .The obstacles can enhance the flame propagation speed , especially for the downstream flame of obstacles with the most obvious effect .The maximum flame propagation speed increases with the increasing amount of obstacles , while the time to reach the maximum flame propagation speed becomes shorter .The obstacles increase the external explosion pressure during the gasoline -air vented explosion process , and the in-creasing range of external explosion pressure peak increases with the increasing amount of obstacles .%为了研究障碍物对油气泄压爆炸火焰传播特性的影响规律，进行了不同数量障碍物工况下的对比实验，并利用纹影仪和高速摄影仪记录了火焰传播过程，针对障碍物对火焰形态、火焰锋面位置及火焰传播速度的影响规律进行了研究，结果表明：圆柱体障碍物会导致油气泄压爆炸火焰形态产生褶皱和弯曲变形，诱导层流火焰向湍流火焰转变，加速火焰的传播，对油气泄压爆炸火焰的初始传播形态有显著影响；随着障碍物数量的增多，火焰锋面传播距离点火端的最大距离增大，但到达最远距离的时间减少；障碍物能够增强火焰的传播速度，尤其对障碍物下游火焰影响最为显著，随着障碍物数量的增多，火焰传播的最大速度也随之增大，但达到最大火焰传播速度的时间却随之减少；障碍物的存在增大了油气泄压爆炸过程外部爆炸压力，并且随着障碍物数量的增多，外部爆炸压力峰值增长幅度增大。