Two-dimensional Imaging of Soot Formation Process during Diesel Combustion by Laser-Induced Incandescence

摘要

This work investigates the effects of various parameters such as ambient oxygen concentration and injection pressure on soot formation process in diesel jet flame using 2-D imaging by use of time-resolved laser induced incandescence (LII). The measurements were conducted using a constant volume combustion vessel that simulated diesel engine conditions. The distribution of soot volume fraction and particle diameter in diesel jet was revealed by time-resolved LII measurements. The experimental results show that the smaller particles are made up of majority of soot formation region in the jet at the early time of the start of soot formation, which become larger around the periphery of the soot formation region with transition to the diffusion combustion phase, and rapidly transform the large particle after the end of injection.