Study of High-Temperature Combustion of Diesel Fuel Spray and Formation and Oxidation of Soot in the Flame using a Rapid Compression Machine

We investigated the effects of a high-temperature environment on diesel spray combustion and formation and oxidation of soot in the flame by eliminating the effects of wall temperature and boundary layer as much as possible using a rapid compression machine which has large combustion chamber. When gas temperature increased, short ignition delay and elongation of combustion was observed by analyzing the cylinder pressure diagram. However disappearance time of luminous flame did not change. Recombination of thermal dissociation must be considered as apparent heat release. Higher surrounding gas temperature results in increased soot formation time and extended low-density soot region in the flame, in spite of almost the same time histories of total amount of soot.