Full scale experimental tests to evaluate the train slipstream in tunnels

The train slipstream, i.e. the air velocity 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 open field, and specific EU standards, the EN 14067-4 and the TSI were issued. Instead, only few studies have been carried out to analyse the train slipstream in confined spaces (as tunnels, line sections with acoustic barriers, etc.), even though 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 fullscale experimental campaign, the effects on the air flow speed caused by the train passage. The effects of different train parameters (i.e. train type and length, etc.) and infrastructure parameters (i.e. geometry variations) were analysed. Lastly, the results of a specific test considering the presence of a stationary train inside the tunnel while another train is passing are described, to simulate scenarios of ordinary railway traffic.

Automated summary

The train slipstream, which is the velocity of air induced by the train, is a significant aerodynamic effect that directly affects the safety of passengers on the platform and track workers along the railway line. While there have been numerous studies on this phenomenon in open fields, such as the development of specific EU standards like EN 14067-4 and TSI, limited research has been conducted on analyzing the train slipstream in confined spaces like tunnels. This study focuses on studying the effects of train passage on air flow speed through full-scale experimental campaigns, analyzing different train and infrastructure parameters and simulating scenarios of ordinary railway traffic with a stationary train inside the tunnel while another train passes.