负压环境下铝镁贫氧推进剂激光点火及燃烧特性  

Laser Ignition and Combustion Characteristics of Al/Mg Fuel-rich Propellant at Subatmospheric Pressures

作　　者：赖华锦 陈雄[1] 周长省[1] 相恒升 LAI Hua-jin CHEN Xiong ZHOU Chang-sheng XIANG Heng-sheng(School of Mechanical Engineering, Nanjing University of Science ＆ Technology, Nanjing 210094, China)

机构地区：[1]南京理工大学机械工程学院,江苏南京210094

出　　处：《含能材料》2017年第10期817-821,共5页Chinese Journal of Energetic Materials

基　　金：国家自然科学基金资助(51606098)

摘　　要：为研究不同负压对铝镁贫氧推进剂的点火及燃烧特性的影响,在负压环境下(0.01,0.02,0.04,0.06,0.08,0.1 MPa)和不同热流下(1.26,1.86,2.23,2.79 W·mm^(-2))采用CO_2激光点火系统对铝镁贫氧推进剂进行点火实验,使用高速摄影仪记录点火燃烧过程,使用两个光电二极管同时监测激光和火焰信号得到其点火延迟时间,研究了负压对推进剂点火延迟时间、燃烧过程和燃速的影响。结果表明,压强影响推进剂热解气体的扩散,压强为0.08 MPa时,初焰为圆柱状,随着压强降低至0.02 MPa,初焰为圆球状;随着压强的降低,推进剂点火延迟时间增加,但随着热流密度的增大,压强对点火延迟时间的影响显著降低;压强对推进剂燃速影响较大,随着压强的降低,推进剂燃速降低,当压强从0.1 MPa降至0.01 MPa时,燃速降低47%;同时,在负压环境下,Vielle燃速公式更适用于表征铝镁贫氧推进剂的燃速特性。In order to study the effect of subatmospheric pressures on the ignition and combustion characteristics of AI/Mg fuel-rich propellant, the propellant was ignited by CO2 laser with different heat fluxes （ 1. 26,1. 86 , 2. 23,2. 79 W · mm-2 ） at subatmospheric pressures （0.01, 0.02,0.04,0.06,0.08,0.1 MPa）. The ignition and combustion process of propellant was recorded by a high speed camera. The ignition delay time was obtained by two photodiodes which monitor the laser signal and flame signal. The effect of subatmospheric pressures on the ignition delay time, combustion process and linear burning rate of the propellant was discussed. Results show that the pressure influences the diffusion of the pyrolytic gases. The initial flame forms the shape of a cylinder when pressure is 0. 08 MPa, as pressure decreases to 0. 02 MPa, the shape of initial flame changes to be spherical. The reduction in pressure causes a longer ignition delay time, however, as the heat flux increases, the effect of pressure on the ignition delay time is significantly reduced. The burning rate decreases with the reduction of pressure and it decreases by 47% when the pressure drops from 0. 1 MPa to 0.01 MPa. The Vielle burning rate formula shows a good agreement with burning rate data. Therefore, the Vielle burning rate formula is more suitable for characterization of A/Mg fuel- rich propellant burning rate characteristics at subatmospheric pressures environment.

关 键 词：铝镁贫氧推进剂 激光辐射点火 负压 点火延迟 

分 类 号：V512[航空宇航科学与技术—航空宇航推进理论与工程]