横向射流起爆爆震波数值研究

Numerical Investigation of the Transverse Jet Effects on Detonation Initiation Characteristics

关键词:  脉冲爆震发动机  起爆  横向射流  数值研究 

Key words:  Pulse detonation engine  Detonation initiation  Transverse jet  Numerical research

摘要:

采用CFD软件对横向喷射的射流在预先充满丙烷/空气恰当比混合物的爆震室中起爆爆震波的过程和机理进行了数值模拟,并讨论了射流的压力、速度以及温度对爆震波起爆特性的影响。结果表明,对于计算的物理模型,爆震射流不能在爆震室中直接起爆爆震波；射流与壁面的碰撞形成激波反射,激波反射产生的横波、热点和局部爆震引发起爆；能够成功起爆爆震波的横向射流存在最小的射流压力,该射流压力为0.9MPa；较小的射流压力、较小的射流速度或较低的射流温度都不利于横向射流在爆震室中起爆爆震波。 

Abstract:

In order to investigate the effects of transverse jet on detonation initiation characteristics, the detonation initiation process was simulated by employing CFD technique. The processes for detonation initiation by the transverse jet with the different conditions were analyzed, and the effects of jet pressure, velocity, and temperature on detonation initiation characteristics were studied. Stoichiometric propane-air mixture was used. The simulation results indicate that the transverse detonation jet can not directly initiate the mixture in the detonation chamber for the physical model. Detonation was indirectly initiated by transverse wave and hot spot and local detonation was caused by the transverse jet. The transverse jet has the minimum jet pressure of 0.9MPa,in which detonation can be initiated successfully by the transverse jet for the physical model. Further decreasing jet pressure or jet velocity or lower jet temperature will not be more difficult to initiate detonation by transverse jet. 