Influences of injector geometry parameters on fuel injection characteristics and parameters of a diesel engine

Abstract

Internal combustion engines (ICEs), especially diesel engines, continue to play a huge role in the development of the global economy. The research trends to improve combustion is still the main research direction in recent years with the help of 3D simulation tools. In this study, a 3D-model of a four-stroke, single-cylinder diesel engine was built using AVL Fire software to evaluate the influence of injector geometry parameters on engine characteristics. The results have shown that, with the injection pressure reaching 3000 (bar), and the turbocharger pressure maintained at 0.15 (MPa), the engine achieves the maximum power and the minimum brake fuel consumption when the angle between the axis of the nozzle hole and the axis of the fuel injection nozzle is 150 degrees. However, at this angle value, the soot emission value is the lowest but the nitrogen oxides (NOx) value is close to reaching the maximum. Hydrocarbon (HC) and carbon monoxide (CO) emissions are the lowest value at 155 degrees of the angle between the axis of the spray hole and the axis of the fuel injection nozzle. Besides, the study also evaluated the engine's parameters when changing the injector hole diameter. With an injection hole diameter of 0.24 (mm), the maximum engine power increased by 5.3%, and the brake-specific fuel consumption decreased by 7.2% compared to other values of injection hole diameter. However, the engine emissions are not the best values in this case.