半封闭空间明火引燃油气特性实验

为研究明火引燃油气着火爆炸特性，建立了半封闭着火爆炸实验平台。通过高速摄影仪拍摄的火焰图像，研究不同油气体积分数下的火焰传播特性。根据高频压力传感器采集的容器内压力变化情况，分析不同油气体积分数下的压力发展特性。结果表明，油气体积分数对火焰组分、火焰传播速度、压力和压力变化速率有显著影响；火焰具有明显的分区现象，可分为燃烧核和火焰阵面，并且纵向火焰阵面速度大于横向火焰阵面速度；容器内压力发展历程可分为4个阶段，而且会形成压力双峰现象；油气爆炸过程中，火焰结构与压力波形成了强烈的耦合作用。

Explosion of gasoline/air mixture ignited by pilot flame in semi-confined space

A semi-confined vessel was built to study the explosion of the gasoline/air mixture ignited by a pilot flame. The flame propagation at different gasoline/air volume fractions were characterized through the flame images from a high-speed camera. The pressures development at different gasoline/air volume fractions were characterized according to the pressure data acquired by a high-frequency pressure sensor. The results showed that the gasoline/air volume fraction had a significant influence on the flame's species, propagation velocity, pressure and pressure rise rate. The flame exhibited an obvious zoning phenomenon, was observed to divide into a flame kernel and a flame front. The speed of the vertical flame front was faster than that of the horizontal flame front. The pressure development process went through four stages, and produced a phenomenon of two pressure peaks. A strong coupling effect was formed between the flame and the pressure wave in the process of the gasoline/air explosion