Abstract
In this study, the spray behavior of direct injection gasoline engines is analyzed under low temperature conditions. DISI engines have a problem of the emission characteristics during cold start. Fuel injection is closely related to PM/PN. The purpose of this study is to understand the spray behavior under low temperature conditions. The experimental equipment to control the fuel temperature and the wall temperature was constructed assuming low temperature condition up to -20°C (253K). The characteristics of free spray and wall impingement spray were measured and analyzed. As the fuel temperature decreased, the spray tip penetration increased by 4.7 % at a fuel temperature of 273 K and by 8.4 % at fuel temperature of 253 K compared to 293 K. The spray angle decreased by 6.4 % at 273 K compared to 293 K, and by 14 % at 253 K. In the case of the wall impingement spray, maximum impingement spray spread distance was suppressed by the change in wall temperature, but the effect of the ambient temperature was also considered.
