Abstract
During the development of the new Alfa Romeo 2 litre JTS engine CFD analysis has been used in the optimisation of the combustion system. Three-dimensional simulations of the intake and compression strokes including gasoline injection have helped in understanding the air-spray interaction and mixture formation inside the combustion chamber. Parametric analysis of the injection timing at various WOT conditions have been performed mainly focusing on its effects volumetric efficiency and fuel distribution prior to ignition. CFD has also been applied at low engine loads and speeds for the optimisation of the piston bowl geometry for stratified charge conditions. Comparison with experimental trends is fairly good although some modelling deficiencies are limiting the level of accuracy of the CFD analysis. Future developments will have to deal with combustion simulation and emissions evaluation.