Prediction of Performance a Direct Injection Engine Fueled with Natural gas–Hydrogen Blends

Abstract-- With increasing concerns about energy shortages and environmental protection, research on improving engine fuel economy and reducing exhaust emissions has become a major research focus in combustion and engine development. Also, with conversion a conventional port fuel injection engine to direct injection (DI) and using alternative fuels, air/fuel mixture can be controlled and the engine is allowed to operate with very lean condition. With appropriate control of the air to fuel ratio gradient, the combustion process allows clean and controlled combustion, resulting in future improvement in fuel economy and emission control. In this study, the effects of mixtures of hydrogen and compressed natural gas (CNG) on a spark ignition engine are numerically considered. This article presents the results of a direct-injection engine using methane– hydrogen mixtures containing H2 between 0 % and 30 % b