Investigating the injection characteristics effect on the performance of diesel engine using an annular injector

Increasing the power and improving the performance of diesel engines is always considered by diesel engine manufacturers. Changing the geometry of the injector outlet orifice has a major impact on fuel-air mixing and combustion. In the current study, the geometry of the injector orifice is changed from circular to annular cross-section, and the effect of different injection pressures on diesel engine performance is investigated. All numerical simulations are performed by using AVL Fire code. The results show that the annular injector improves combustion and engine performance by forming better fuel distribution. Fuel injection pressure affects the performance of the annular injector in terms of droplet distribution and breakup. At low injection pressures, due to the long injection duration, most of the fuel energy release occurs after the top dead center (TDC). Therefore, the engine performance is improved, and the combustion chamber temperature and pressure are limited. However, at high injection pressures, less combustion occurs after the TDC. By changing the injector geometry to the injector with an annular cross-section orifice, the maximum reduction in SFC value is for case P۵ and injection durations ۱۰ degrees, which is decreased by ۲۱.۴%. The maximum power increase was ۱۵% for a ۲.۵% fuel increase at an injection pressure of ۱۰۰MPa. While NO pollutant increased slightly by changing the type of injector at different injection pressures, the soot produced at the beginning of the combustion process was well oxidized before the end of the work phase, and its amount reached less than ۲e-۶.

کلیدواژه ها:

Annular injector ، Injection pressure ، Injection duration ، Engine performance ، Specific fuel consumption