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In this work an experimental analysis is performed to evaluate the influence of different flow bench test conditions and system configurations on the flow characteristics in the intake system of a high performance 4-valve, SI Internal Combustion Engine: valve lift, test pressure drop, throttle valve aperture, throttle valve opening direction in respect to the intake system layout (i.e. clockwise/counterclockwise), presence of the tumble adaptor. To this aim, experimental tests are performed on a Ducati Corse racing engine cylinder head, by measuring the discharge coefficient and the tumble coefficient. The several experimental data obtained by combining the different operational and geometrical parameters are analysed and discussed.

Design processes of modern race car are often developed in short time; during this period a large number of parameters has to be tuned to reach best results. Many kind of vehicle dynamics simulation models have been developed by car manufacturers and private suppliers to investigate car behavior on racing tracks. Such models have a high degree of complexity but they can be employed, in a simplified mode, during design processes of racing cars for which tracks technical data (for such circuits where they will race) are well known. During the first stages of the design activity very complex numerical models (such as multibody simulations) are not necessary and it is possible to use simplified methods to locate optimal solutions in a fast way. In present work a numerical model, able to reproduce car behavior on a defined circuit or simply analyze meaningful test cases (breaking, steering,…), is used to appraise performances of race car with different technical configuration.

In this paper a numerical analysis is carried out of the flow characteristics in the intake system of a high performance engine. To this aim, the experimental flow bench results - obtained in tests performed on a Ducati Corse 4 valves racing engine head and presented in the parallel work [1] - are compared with the numerical ones. In [1] an experimental analysis was performed to evaluate the influence, on the flow characteristics in the intake system of a high performance 4 stroke - 4 valve internal combustion engine Notwithstanding the macroscopic meaning of the measured global coefficients Cd (Discharge Coefficient) and Nt (Tumble Number), the comparative analysis of their respective trends allowed some hypotheses to be drawn on the flow development internally to intake system ducts. In order to confirm the conclusions drawn in [1] and to reach a deeper insight in the flow characteristics, numerical simulations were performed.