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The design of new geometries of combustion chambers together with the design of improved intake systems are some of the most important applied research activities that attempt to improve the complex processes underlying combustion. The design and the analysis of new optimized geometries which use numerical simulations, based on a commercial CFD code utilization, seems to be a very interesting way to reduce the industrial costs in the engines developing activity. In the present work, steady state simulations of an intake system of a race engine head of Ducati Corse , using a commercial 3D-CFD code, are carried out to tune the parameters of the used models and to analyze different configurations. The models validation is based on the experimental results obtained from a parallel paper concerning the Tumble Coefficient (Nt) and the Discharge Coefficient (Cd) obtained using two configurations: with an L-shaped tumble adaptor and a standard one.

This present work is aimed to the analysis of the possible advantages that could be obtained exploiting Variable Valve Actuation strategies in an high performance engine head. A set of experimental tests was carried out to obtain maps of the discharge, tumble and swirl coefficients, at any combination of asymmetric lifts of the two intake valves. The results show that asymmetric strategies could allow engine part load operation characterized by enhanced tumble/swirl generation, while keeping the same effective flow area of conventional two valves symmetric lift. Numerical simulations allowed a deeper understanding of the tumble motion characteristics at different lift combinations, and in particular for asymmetric low lifts cases where the lack of the typical abrupt tumble rising zone was noted.