Experimental study of spray behavior and laser ignited combustion characteristics of a gasoline-air mixture using the GDI system

Abstract

This study focuses on the spray behavior and combustion characteristics of laser ignited gasoline-air mixture. A gasoline direct injection (GDI) system was used to inject the gasoline-air fuel mixture with high injection pressure into a constant volume combustion chamber. This high-pressure injection helps to improve the mixing quality and atomization, which further enhances the combustion process. The spray characteristics were studied for the injection pressures of up to 11 MPa in steps of 2 MPa, injection duration 1 to 5 ms, and a chamber pressure of 0.1 to 0.7 MPa. The maximum spray penetration length was found at 11 MPa injection pressure. The dependence of spray characteristics was found dominant on injection pressure compared with the injection duration. The experimental results were validated with CFD simulations. The empirical correlation was developed for spray penetration length, which was further used to calculate the spray penetration length for the gasoline-air mixture's laser combustion. The laser combustion was done at all the injection pressure ranges to study the effect of injection pressure on combustion peak pressure. An increase in peak pressure was found with an increase in injection pressure. The combustion peak pressure and the net heat release were found maximum for ϕ = 1, reducing lean and rich mixture conditions.