液氧甲烷发动机点火冲击特性研究

Ignition Shock of LOX/Methane Liquid Rocket Engine

关键词:  点火冲击  液氧甲烷发动机  推力室  再生冷却  C-J爆轰波  液滴蒸发模型

Key words:  Ignition shock  LOX/Methane rocket engine  Thrust combustion chamber  Regenerative cooling  Chapman-Jouguet detonation wave  Droplet evaporation model

摘要:

为研究液氧甲烷发动机燃烧室点火冲击特性及影响因素，根据爆轰波产生的机理，建立了甲烷推进剂液相蒸发数学模型，采用C-J（Chapman-Jouguet）爆轰理论，计算和分析了不同混合比、初温及初压对爆轰参数的影响规律。结果表明，爆轰波的强度与初压、初温及混合比密切相关。初压越高，初温越低，越接近化学当量混合比时，爆轰压比、温度比和爆轰速度越大；减小点火时刻推进剂积存量，增强燃烧装置点火能力，可降低爆轰波强度，减少点火瞬态冲击。

Abstract:

In order to study the ignition shock characteristics and influence factors in combustion chamber of LOX/Methane rocket engine， a liquid phase evaporation mathematical model of methane propellant was established based on the mechanism of detonation wave. The effects of different mixing ratio， initial temperature and initial pressure on detonation parameters were calculated and analyzed by using Chapman-Jouguet detonation theory. The results show that the intensity of detonation wave is closely related to initial pressure， initial temperature and mixing ratio. As the initial pressure increases and initial temperature decreases as well as the equivalence ratio becomes closer to the stoichiometric ratio， the detonation pressure ratio and temperature ratio as well as detonation velocity increase. Reducing the propellant accumulation at ignition time and enhancing the ignition ability of combustion device can reduce the detonation wave strength and reduce the transient impact of ignition.