Multiple Pilot Injection Spray Evolutions Emerging from a Multi-holes HPCR Injector

摘要

A CFD analysis of spray evolution emerging from a multi-holes injector has heen carried out to investigate the influence of pilot and main fuel injection patterns on in-cylinder fuel distribution cluring cold idling.Combustion system and injector arrangements mimic a modern design HPCR diesel engine meeting Euro 4 requirements.Analysis covers evolutions from intake valve closing to start of combustion.Multiple pilot injections are capahle of better fuel distribution,both on the spray axis ancl spatially throughout the cylinder.Three pilots allow for the entire combustion chamber heing occupied by fuel/air mixture;a greater proportion of the fuel is exposed to the high glow plug temperature.Increasing number of pilots makes mixing less sensitive to swirl ratio.