The role of ventilation on the dispersion of fire gases inside a tunnel

Tunnel fires represent a serious threat for underground, rail and road safety, due to their potential severe consequences in terms of loss of lives, economic consequences and operational discontinuity. Given the fundamental role of tunnel ventilation in both normal and emergency conditions and the lack of any systematic analysis, a numerical analysis has been carried out in order to compare different ventilation configurations and to assess their effect on smoke and pollutants dispersion inside a tunnel for a typical fire scenario. The software Fire Dynamics Simulator (FDS), developed by NIST, was used for the modeling activity. The present study evidenced that the use of computational fluid dynamics (CFD) models in this field can be useful especially for designing adequate ventilation systems and the necessary escape routes.