Abstract
LII measurement was performed to investigate the soot formation process in a region where diesel spray flames impinge onto the wall and adjacent these flames interact with each other. It was carried out using an optical accessible RCEM with a two-hole injector. Effects of injection pressure and ambient oxygen concentration was discussed．It was found that high concentrations of soot were formed in the interaction region, soot was formed in a wider range and remained for a long time when reducing the injection pressure, and soot was formed even when increasing the oxygen concentration, but it is reduced earlier.
