Investigation on temporal change for adhesion fuel mass of DI gasoline spray impinging on a wall

Particulate matter (PM) emission from direct-injection (DI) gasoline engines are caused by pool combustion of fuel adhering on a piston wall. It is necessary to clarify the formation process of liquid fuel film. In this study, temporal change of fuel mass adhered on the wall was evaluated to understand the adhesion process of a liquid fuel film by using total internal reflection laser-induced fluorescence (TIR-LIF) technique. As a result, the mass of the liquid film increased during the fuel injection period, and it decreased rapidly during the period that spray tail after the end of injection reached the wall surface.