Aspects on injection pressure for diesel and gasoline DI engines

Abstract

Aspects on injection pressure for diesel and gasoline DI engines 448 1 Summary Since the very beginning of providing fuel metering equipment for combustion en-gines, injection pressure is a key enabler for mixture preparation and spray perfor-mance, fulfilling the task to bring the fuel into the combustion chamber in the right time, with the right quality to the right place. This paper deals with the role of injec-tion pressure for Diesel and Gasoline Direct Injection combustion processes. Future requirements on propulsion coming from the overall market trends especially on emission and CO2 by means of fuel consumption are discussed. As the key tech-nology for internal combustion engines direct fuel injection in Gasoline and Diesel plays a major role gaining the challenging development targets like power output, comfort, lowest emission and benchmark fuel consumption at attractive cost level. This trend is already established in Western Europe and North America followed by the Asia market and will be rolled out in the next upcoming decade. There is no alter-native than using that technology in a broad manner fulfilling overall CO2 emission legislation. Diving deeper in the DI technologies one obtains the injection pressure as main key performance indicator. Looking at Diesel the energy cascade starts from pressure via spray momentum to spray penetration and ends up in a vapor liquid multi phase fluid which is burned in the combustion chamber in order to realize best combustion results defines the core of injection technology. Some multidimensional optimization of con-tradictionary targets is discussed and results are shown. Consequences on the system and component layout follow to deliver high pressure injection technology in a most efficient way.