A Study on Soot Formation and Oxidation of Ethanol / Diesel Blends Using the Two-Color Method

In this study, two dimensional distribution of flame temperature and soot concentration was measured with constant volume vessel by the two color method for diesel ethanol blends. As a result, because two factors of decreasing soot formation, which are low adiabatic flame temperature and high oxygen concentration, are synergistic in the beginning of combustion, soot formation is reduced remarkably. In the later stage of the combustion, the flame temperature does not fall, so two enhance effects of soot oxidation, which are early reversal timing and high oxygen concentration, are synergistic. Therefore, in case of diesel ethanol blends, soot formation is reduced by low adiabatic flame temperature and high oxygen concentration, and soot oxidation is enhanced by early reversal timing and high oxygen concentration. Even for an actual engine, soot emission will be decreased because soot formation is reduced and soot oxidation is enhanced.