The Channel Tunnel is a 50km-long infrastructure comprising two rail tunnel and a third service tunnel.


These two rail tunnels are connected every 250m by connexion galleries with a 2m-diameter cross section. These galleries also allow for the reduction of the aerodynamic resistance of the tunnel.


As part of an assessment of the aerodynamic effects inside the tunnel, the aim was to analyse the air flow around the freight trains as well as in the galleries mentioned above. This assessment was undertaken with the use of a CFD 3D model produced with the Ansys-Fluent software.




setec tpi in partnership with setec bâtiment undertook the aerodynamic phenomena studies over a section of the tunnel:

  • Study of the 3D model’s limit conditions with the use of Express’Air (1D software). Simulation of the crossing of two freight trains.
  • Modelling of 1,250m of the tunnel’s geometry with a freight train loaded with lorries.
  • Creation of the 3D modelling grid.
  • 3D modelling analysis over a duration of 1 min.
  • Assessment of the results for each of the train traffic configurations: spectrum of pressures et air flow inside the tunnel.


Key information


Client: Eurotunnel

Duration:  2013


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