1-d Calculations of Pressure Changes due to Passage of an ETR 500 through the Terranuova le Ville Tunnel

Summary

This paper describes the comparison of measured and numerically simulated pressure variations of the kind that occur when rail vehicles pass through a tunnel.

Forming the basis for the comparison were data from eight test runs conducted within the framework of the EU Transaero project in the Terranuova le Ville Tunnel, on the Italian Direttissima line between Rome and Florence.

The data set for a test run generally comprised pressure variations at 3 positions on the outside of the train, pressure variations at the same 3 positions inside the train and pressure variations at 8 fixed positions in the tunnel The comparisons were each carried out in such a way that, initially with one value for tunnel friction coefficient and train friction coefficient respectively, optimum simultaneous consistency of the numerical simulation with all external pressure variations and fixed pressure variations was achieved. This mode of procedure ensured that, by sacrificing the optimum consistency that could have been attained by comparing the individual pressure variations of a test run, only one set of coefficients is identified per test run.

Using the external pressure variations previously computed, the internal pressure variations were then calculated in such a way that, with pressure seal coefficients varying from car to car, the best possible consistency between measured and computed internal pressure variations was achieved.