Downsizing of Common Rail D.I. engines: influence of different injection strategies on combustion evolution

This paper refers to the experimental results obtained using two different 4-cylinder diesel engines, with total displacement respectively equal to 1.9 L and 1.3 L, both equipped with an advanced common-rail system. An optically accessed prototype engine, having characteristics similar to the four-cylinder engine, is used to visualize the incylinder phenomena. Multidimensional simulations of the combustion and pollutants formation processes are performed, comparing the numerical predictions with the experimental data. By this way, integrating the 3D C.F.D. computations, the visualization techniques of the injection and combustion processes and the field measurements on the real engines, different settings of the multiple injection strategy have been analyzed.