Analysis of Advanced Air and Fuel Management Systems for Future Automotive Diesel Engine Generations

The increasing stringency of pollutant emissions regulations, aiming to fuel neutral NOx limits, is expected to foster the implementation of new technologies in terms of aftertreatment, air management and fuel injection systems. In this field, modern diesel engines are equipped with electronically-controlled flexible fuel injection systems and air/gas/EGR control valves. The only part in the air system ‘left for revolutionary’ is the valvetrain and a fully flexible Variable Valve Actuation (VVA) is becoming nowadays highly desirable for modern diesel engine. In this context, the purpose of the research activity was, on one hand, to evaluate and identify, through numerical simulation, the best VVA strategies to be implemented in a passenger car diesel engine by quantifying and choosing benefits vs drawbacks of VVA strategies. On the other hand, the definition of the best injection pattern for BSFC, Emission and NVH improvements through the adoption of Genetic Algorithm was performed. The EURO VI medium diesel engine (1.6 l 4L) developed by General Motors Global Propulsion Systems was selected as case study.