Experimental analysis of train slipstream in confined spaces

The train slipstream, i.e. the air velocities induced by the train, is one of the most important aerodynamic effects connected to railway vehicles because it has a direct impact on the safety of passengers on the platform and track workers along the railway line. In recent years, a lot of studies were performed to understand the development of this phenomenon in the open field and specific EU standards, the EN 14067-4 and the TSI (Technical Specifications for Interoperability) were issued. On the other hand, only few studies have been carried out to analyze the train passages in confined spaces (as tunnels, line sections with acoustic barriers, etc.), even if the first results of these analyses have shown that the confinement of the air causes more severe conditions regarding the speed of the air flow. This work aims at studying, through a full-scale experimental campaign, the effects of the flow confinement on the air speed caused by the train passage. In particular, the effects of different parameters, linked to the train i.e. the train type and length, the train speed and the measurement position, and linked to the infrastructure i.e. variations in the local infrastructure geometry, were analyzed.