In order to obtain the unstable combustion characteristics of RP-3 aviation kerosene,exper-iments are carried out in a constant volume chamber to study the unstable combustion process of RP-3/O2 premixed flame at initial pressures of 0.1 MPa,0.2 MPa and 0.3 MPa,initial temperatures of 420 K, 450 K and 480 K and over a wide equivalence ratio range from 1.0 to 1.7.Results show that with the in-crease of initial pressure and equivalence ratio,the flame front obviously changes from smooth to folded, and cellular structure appears inside,which indicates that the flame tends to be unstable.The study on initial radius of transition acceleration indicates that with the increase of initial temperature,initial pres-sure and equivalence ratio decreases,which means that the instability of premixed flame is advanced.By calculating the disturbance growth rate and analyzing its influence on flame stability,it is found that the effect of mass and heat diffusion on flame stability is dominant,and the effect of hydrodynamics is sec-ondary.The mass-thermal diffusion mainly depends on the molecular diffusion term.With the increase of the equivalence ratio,its value changes from negative to positive,which indicates that the molecular dif-fusion has an enhanced effect on the instability of premixed flame.
关键词
RP-3航空煤油/不稳定燃烧/过渡加速起始半径/质热扩散作用/流体动力学作用
Key words
RP-3 aviation kerosene/unstable combustion/initial radius of transition acceleration/mass-thermal diffusion/hydrodynamics
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