热射流点火对爆震管内火焰加速及爆震波触发影响的数值研究

为研究热射流点火对爆震管内火焰加速及爆震波触发的影响,运用34步26组分丙烷基元反应进行了二维数值模拟,获得了5种不同的热射流发生器几何结构下的爆震管内火焰传播规律及缓燃向爆震转捩(deflagration to detonation transition,DDT)的时间与距离.结果表明:爆震管中湍流在火焰加速阶段起着重要作用,在爆震波触发阶段激波与火焰相互作用占有主导地位.根据DDT过程的定义,得到DDT时间在1.4~2.0ms之间,同时发现热射流发生器长度为150mm,热射流发生器孔径在8mm时DDT时间最短,热射流发生器长度及孔径对DDT距离的影响不大. 

Numerical study on effect of hot jet ignition on flame acceleration and detonation initiation in detonation tube

To study the effect of hot jet ignition on flame acceleration and detonation initiation in detonation tube, 2-D numerical simulations with propane mechanism including 34 reaction steps among 26 chemical species were performed, and the flame propagation law in detonation tube and deflagration to detonation transition (DDT) time and distance were obtained with 5 different configurations of hot jet sub-chamber. The results show that turbulence plays a key role during flame acceleration process in detonation tube, and the shock/flame interaction dominates the detonation initiation. According to the definition of DDT process, the DDT time is between 1.4-2.0ms, and the minimum value is obtained in the hot jet sub-chamber with 150mm length and 8mm in orifice diameter. The hot jet sub-chamber length and orifice diameter exert a minor effect on the DDT distance.