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A zero-dimensional dynamic model was developed in the Matlab/Simulink® environment to predict the behaviour of a variable-displacement lubricating vane pump for internal combustion engine applications. Based on the geometric and kinematic characteristics of the pump, the model allows predictions of the pressure evolution in each chamber of the pump and in the delivery piping, by employing an integrative-derivative approach. Simulation results were compared with experimental data of pressure transducers, which were fitted along the periphery of the pump case and in the delivery channel. The analysis of the experimental data shows that the pressure dynamics, which is experienced by the transducers, is in some cases quite different from the pressure dynamics in the pump chambers and produces pressure peaks which are not actually present in the original signal. The pressure transducers output was then also modelled in order to properly compare simulation results and experimental data.

The fluid dynamic efficiency of two different four-valve high-performance engine heads has been compared both in terms of global mass flow rate and in terms of local velocity distribution around the valve curtain, by means of LDA measurements. The two engine heads have the same bore and valve diameters, but a slightly different valve position and valve stem inclination. Results clearly show that valve-wall distance is a critical factor for head permeability and that even marginal variations in valve position and inclination lead to appreciable differences in flow pattern and total flow rate.