Injection System Design Optimization by Considering Fuel Spray Characteristics

Abstract

This paper considers optimal design of an electronic control diesel fuel injection system by considering fuel spray characteristics. The proposed design procedure relies on the assumption that the atomization of fuel spray influences the diesel engine performance, fuel consumption and harmful emission significantly. As a measure of spray atomization the Sauter mean diameter is employed. The design problem is formulated in a form of a multiobjective optimization problem taking into account the Japanese 13 Mode test for diesel engines of commercial vehicles. Two different transformations from the multiobjective to the standard form are proposed and the results are compared to each other. The design variables of the injection system are related to the shape of the cam profile, to the nozzle geometry and to the control parameters influencing the injection quantity and timing. The geometrical properties of the cam profile as well as some injection parameters are kept within acceptable limits by the imposed constraints.