On the accuracy of the assessment of open-air pressure loads due to passing trains. Part 2: Assessment by simulation

Passing trains generate aerodynamic loads that cause fatigue on wayside objects and other trains. The European regulatory framework requires, for every rolling stock type, type-tests in which the peak-to-peak pressure changes caused by passing trains are measured close to the track over a range of heights, corrected and processed so as to obtain an assessment value, which is then compared with a limit value. The assessment value is characterized by uncertainty. In this paper we provide quantitative indicators of such uncertainty based on the work carried out in the European FP7 project AeroTRAIN. We compare such accuracy indicators for assessments performed both experimentally, based on the existing process, and through computational fluid dynamics, based on an assessment-by-simulation process proposed in AeroTRAIN. We show how the accuracy of the proposed process can be even slightly better than that of the existing process