爆震波与非预混燃料射流相互作用的研究

Interaction Between Detonation and Non-Premixed Fuel Jets

关键词:  线性模型  爆震发动机  非预混环境  掺混均匀度  爆震波传播

Key words:  Linear model  Detonation engine  Non-premixed environment  Mixing evenness  Detonation propagation

摘要:

为研究旋转爆震发动机（Rotating detonation engine，RDE）中燃料/氧化剂喷射和掺混对爆震波的影响及非预混环境下的爆震波的快速起爆与稳定传播，采用线性模型爆震发动机（Linear model detonation engine，LMDE）来简化实际燃料喷射与爆震波相互作用的物理问题。通过RNG k-ε湍流模型结合7步7组分氢气/空气机理的三维非定常反应流模拟方法，探究真实喷射条件下爆震波与混气相互作用、爆震波衰减及自持的特性。结果表明：氢气/空气的掺混均匀度至少要达到0.6才能使爆震波在非预混环境下传播；氢气孔与空气缝的入口压比需要满足爆震波进入燃烧室时，非均匀混气区恰好集中在氢气孔附近，燃料完全释放能量维持爆震波传播。

Abstract:

In order to investigate the effects of fuel/oxidizer injection and blending on detonation and the rapid initiation and steady propagation of detonation in non-premixed environment in the rotating detonation engine （RDE）， a linear model detonation engine （LMDE） is used to simplify the physics problem of interaction between real fuel injection and detonation wave. The RNG k-ε turbulence model combined with the three-dimensional unsteady reaction flow simulation method of 7 steps， 7 species hydrogen/air mechanism are used to investigate the interaction between detonation wave and mixed gas， attenuation of detonation and self-holding characteristics in real inject conditions. The results show that the mixing evenness of hydrogen/air should be at least 0.6 to make the detonation wave propagate in the non-premix environment. The inlet pressure ratio between hydrogen holes and air slot needs to meet the requirement that when the detonation enters the combustion chamber， the region of non-premixed gas is just near the hydrogen holes， and the energy is completely released to maintain the propagation of the detonation.