Experimental and computational analysis of a dynamic model for control strategy optimization in a spark ignition engine

In the framework of a mean value dynamic model for the prediction of fuel consumption and emissions during driving cycles, the air flow and the two phase fuel flow sub-models are presented. To validate these sub-models, an experimental investigation on an electronically controlled multi-point injection engine has been carried out. A satisfactory agreement between predicted and measured data is obtained consistently with the objectives of the whole engine dynamic model. Furthermore, the identification study for the fuel flow dynamics, conducted via a least square technique, provides the basic information in describing the fuel behaviour for a port injection engine. Particularly no dependence from engine parameters has been noticed except for the amount of fuel flowing through the intake valve as liquid phase.