Abstract
In order to reduce particulate matter (PM) emitted from a gasoline direct injection spark ignition (DISI) engine, it is important to reduce the fuel film deposition on the wall and the local rich air-fuel mixture formation. As a means to reduce these, the high pressure fuel injection is considered to be effective. In this study, we evaluated the influence of increasing fuel injection pressure to PM emission with using the glass cylinder engine at fast idle operation. The fuel film deposition on the piston was measured by using ultraviolet irradiation to cause excited fluorescence in the fuel which contained the fluorescent agent. And, the fuel liquid and vapor phase was measured by using Laser Induced Exciplex Fluorescence (LIEF) method. The number of PM from a DISI engine was decreased by increasing fuel pressure from 20MPa to 80MPa. The fuel film deposition on the piston was decreased by increasing the pressure. The area of the liquid phase inside the combustion chamber was reduced, and the variation of vapor phase was decreased by increasing the fuel pressure.
