Combustion chamber design effects on D.I. common rail Diesel engine performance

In the present paper the KIVA3V code is used to model the behavior of different combustion chambers, to be used in common-rail engines with a single displacement lower than 0.51. Some design parameters have been chosen to evaluate their influence on the combustion patterns. The optimum levels of turbulence and air mean motion have been selected with reference to some specific points of the engine map, managed by means of multiple injection. Therefore the different combustion chambers geometries have been numerically investigated in terms of fluid dynamic behavior as well as in terms of combustion evolution. After that some chamber geometries, especially suitable for the second-generation common-rail engines, have been selected.