突扩微管中二次起爆的数值研究
Numerical Study of Detonation Re-initiation Inside a Sudden Expansion Micro-tube

为研究微尺度下爆震波经过突扩管的二次起爆特性，采用恰当比的乙烯（C2H4）与氧气（O2）（或恰当比的氢气（H2）与氧气（O2））的混合气，在不同突扩比的管道内进行了爆震数值研究。结果表明，燃料与突扩比都会对二次起爆产生影响，在一定突扩比范围内，突扩比越大，起爆距离与时间越长。对于相同突扩比，C2H4/O2混合气相比较于H2/O2混合气缓燃转爆震的时间短，但H2/O2混合气比C2H4/O2混合气二次起爆的突扩比范围宽广；H2/O2混合气突扩比超过7、C2H4/O2混合气突扩比超过5时化学反应区与激波将不能够再次耦合形成爆震波。
To investigate the characteristics of detonation re-initiation when the detonation wave go through a sudden expansion micro-tube, numerical study was carried out in different sudden expansion ratio tubes with the stoichiometric ratio of ethylene and oxygen (or the stoichiometric ratio of hydrogen and oxygen). Simulation results showed that, both the fuel and the sudden expansion ratio would affect the detonation re-initiation, and the larger the sudden expansion ratio is, the longer the detonation distance and the time are within a certain range of sudden expansion ratio. For the same sudden expansion ratio, the time of deflagration-to-detonation transition (DDT) was shorter for C2H4/O2 mixture, but the H2/O2 mixture has a wider expansion ratio range of the sudden expansion ratio for successfully detonation re-initiation. When the sudden expansion ratio was more than 7 for H2/O2 mixture, and the sudden expansion ratio was more than 5 for C2H4/O2 mixture, the chemical reaction zone and shock wave will not be able to couple again to form a detonation wave