The Fréjus Road Tunnel is a tunnel that connects France and Italy. It runs under Col du Fréjus in the Cottian Alps between Modane in France and Bardonecchia in Italy. It is one of the major trans-Alpine transport routes between France and Italy, and it is used for 80% of the commercial road traffic.

Mechartes was appointed as the CFD Consultant for the project to optimize the number and location of tunnel ventilation fans. Jet fans were used in the study, and we optimized their number and placement through a normal ventilation study.

After finalizing the design, we conducted a CFD smoke analysis to study the tenability conditions, including smoke concentration, velocity, radiant heat flux, temperature, and visibility for various locations and fire sizes.

This analysis ensured compliance with NFPA 502 and PIARC (World Road Association) standards, guaranteeing the safety and effectiveness of the tunnel ventilation system.