两点火源顺序点火起爆爆震波的数值研究 *

Numerical Investigation of Two Successive Ignitions Effect on Detonation Initiation

关键词:  起爆  顺序点火  点火间隔时间  点火距离  脉冲爆震发动机

Key words:  Detonation initiation  Successive ignitions  Ignition interval time  Ignition distance  Pulse detonation engine

摘要:

为了研究两点火源顺序点火对爆震起爆的影响，对单点火源以及不同间距、不同点火间隔时间的两点火源点火起爆过程进行了数值模拟。采用恰当比的丙烷/空气为可爆混合物。计算结果表明，在单个点火源不能起爆爆震波时，在其下游一定距离的位置增加一个相同能量的点火源并在适当的点火间隔时间下顺序点火可以起爆爆震波；两个点火源的距离一定时，点火间隔时间需在一定范围内才能成功起爆爆震波；当点火源距离从50mm增加到150mm时，成功起爆爆震波的点火间隔时间的范围从10μs减小到0.5μs。

Abstract:

In order to investigate the effect of two successive ignitions on the characteristics of detonation initiation，the detonation initiation process was numerically simulated by CFD software. The processes of detonation initiation by one ignition and two successive ignitions with different distances and different ignition interval time were simulated and analyzed. Stoichiometric propane-air mixture was used as the fuel-oxidant. The simulation and analysis results indicate that the detonation wave in the detonation tube can not be initiated by one single ignition，but can be initiated when the successive second ignition with the same energy is added in the downstream and is ignited at the appropriate interval time. When the distance between the two ignitions is constant，the detonation wave can be initiated successfully by the two ignitions with a certain range of ignition interval time. When the distance between the two ignitions increases from 50 mm to 150 mm，the range of the ignition interval time decreases from 10μs to 0.5μs，with which detonation can be initiated.