Sviluppo di un codice di simulazione dinamica per lo studio di treni merci di futura generazione

In this PhD thesis, mainly carried out at Faiveley Transport Italia Spa, it has been further developed a numerical code, called “TrainDy”, able to study the dynamic behaviour of freight trains. I this work, the full model of the braking train system has been implemented in TrainDy, using the know-how and the devices, bought hardware and software, given by Faiveley Transport Italia. Moreover, the model of longitudinal dynamics has been improved, the code was been modularized and now it is able to simulate trains with vehicles schematized with different number of degree of freedom. The fluid-dynamic model of the main brake pipe solves the three continuity equations, written for a pipe with a variable section along its longitudinal axis, following the quasi-mono-dimensional scheme. Furthermore, the air can flow throughout the lateral directions (i.e. perpendicular to longitudinal pipe axis); by this way, it is straightforward taking in account for more than one master brake valves. The master brake valve, the distributor and its volumes, has been schematized by means of equivalent formulations, which use parameters achieved from experimental data and the results obtained from the commercial code AMESim®. This model of complete braking system has been widely verified using the experimental data furnished by Faiveley. Moreover, ones the braking model has been verified, the new version of code TrainDy has been employed in order to study the main effects of obstructions along the main brake pipe, of the repetition of braking command, considering trains with different length and mass. Through this studies, the safe working conditions of future trains, that overcome the actual limits of railway standard, have been pointed out.