Analysis of critical air velocity in a road tunnel fire

A critical air velocity analysis was performed using a numerical model adapted for the eastern tunnel tube of Kastelec road in Slovenia. This allowed efficiency fans to be tested, which is required maintain appropriate traffic conditions and prescribed safety tunnel. At velocity, that is, at an lower than one, where spread smoke can still effectively controlled ensure time safe evacuation passengers from fire-endangered tube, special attention paid phenomena backlayering layered under ceiling (so-called “stratification”). Simulations longitudinal ventilation system with single point extractions were conducted.