Formation and Oxidation Processes of Soot Particulates in a D. I. Diesel Engine — An Experimental Study via the Two-Color Method

The formation and oxidation processes of soot particulates in a D. I. diesel engine were investigated under various operating conditions through the measurements of KL factor and flame temperature via the two-color method, whose reliability had been substantiated by a comparative measurement with the direct sampling method. The measured time histories of KL factor and flame temperature show that under all conditions studied soot is promptly formed just after the start of diffusion combustion phase and peaks at around the end of injection, then is oxidized rapidly, followed by the termination of oxidation when the flame temperature drops to 1800 K.