受侧向膨胀影响的爆震波传播过程研究

Investigation on Propagation Process of Detonation Wave Influenced by Lateral Expansion

关键词:  侧向膨胀  波面形状  横波  速度亏损 

Key words:  Lateral expansion  Shape of detonation front  Transverse wave  Velocity deficits

摘要:

基于Fay流体扩张理论,运用实验观测、数值模拟和理论分析等方法研究了侧向膨胀对爆震波传播过程的影响。详细分析了爆震波在侧向膨胀段的流场结构,由于气体可压缩壁面限制性作用较弱,爆震波强度受到不同程度衰减,波面发生一定变形,横波数量明显减小且横波间距增大。对比研究了预混气活性对爆震波流场结构和传播过程影响,实验发现预混气活性较高时,即ER=1.0,爆震波能够抵御侧向膨胀衰减影响,能够自持传播；预混气活性较低时,即ER=0.7,其抵御侧向膨胀能力较弱,速度亏损变大,波面变形严重,爆震波解耦而熄爆。若要维持爆震波在气体可压缩壁面稳定传播,需要一定活性来抵御侧向膨胀影响。 

Abstract:

Based on Fay’s fluid expansion theory, a detailed study for the effect of lateral expansion on the flow field of detonation waves was performed with experimental observation,numerical simulation and theoretical analysis. The detonation wave structure in the lateral expansion section was analyzed in detail. As the confinement of the compressible boundary was weak, the detonation wave was attenuated in different degree with the detonation front deformed, and the number of the transverse wave was significantly reduced with the spacing increased. The influence of the sensitivity of premixed gas on the detonation wave was analyzed. It is found that when the sensitivity of premixed gas is high, such as ER=1.0, it could resist the attenuation of the effect of lateral expansion.When the sensitivity of premixed gas is low, the detonation front of ER=0.7deformed severely, leading to decoupling of the detonation wave. To sustain the detonation wave propagating in the compressible boundary,the sensitivity of the premixed gas should be high enough. 