Investigation of the effect on engine performance of using natural gas in a stratified charge gasoline engine

The increasing number of vehicles due to the increase in the world population and the fact that most of these vehicles are dependent on fossil fuels poses a threat to the environment and the future of our world. Therefore, the use of alternative fuels and efforts to improve engine efficiency constitute an area of research that is of interest to scientists. Among the alternative fuels, the selection of natural gas in this thesis is a high number of octane number, it is environment-friendly and it is used in petrol engines without any modification. In studies to improve engine efficiency, the shape of the fuel to the cylinder is an important parameter. It is possible to improve the combustion efficiency by spraying the fuel gradually into the cylinder. Within the scope of this thesis study, the use of natural gas with stratified charged gasoline engine was investigated in ANSYS Forte 19, which 3D computational fluid dynamics software. As a model, a full port model has been designed to give the closest result, and CH4 has been selected as the fuel to be sprayed from the injector, which constitutes the majority of natural gas. In the first part of the study, the amount of fuel to be sprayed at each stage was investigated. In the second part, the timing of the fuel to be sprayed in the second stage is examined. As a result of the investigation, it was seen that spraying a small amount of fuel in the second stage and delaying the timing of the second stage positively effect engine performance, combustion efficiency and emissions.