Optimization of Fuel Inlet Port Geometry of an Air Assisted Diesel Injector

Abstract

Diesel fuel is injected into the combustion chamber by the use of injectors. Atomization process is characterized by directing extremely pressurized fuel into the injector orifices in modern injectors. However, this high pressure level, which exceed 1300 bars in some cases, causes cavitation before discharge nozzle and results in mechanical wear. In air assisted atomizers, pressured air is utilized for atomization. This type of injectors eliminates cavitation erosion by reducing injection pressure and they create finer spray geometry. Mixing process of air and fuel has a vital importance since it directly affects level of atomization in air assisted atomizers. Therefore the aim of this study was determine influence of different inlet port geometries on flow characteristics of a specially designed diesel injector which is developed for diesel fuel atomization, by using computational fluid dynamics techniques.