The damage of the road tunnel during tunnel ventilation tests is prevented by using specific testing aerosol representing fire smoke. This study compares optical density profiles of aerosol and fire smoke using the well-known FDS simulation system, testing the suitability of aerosol to represent fire smoke realistically. The movement of aerosol and fire smoke downstream of the aerosol/fire source is investigated for a case of a 240 m long section of a road tunnel. Similarity of optical density profile for both cases under given conditions is confirmed. The influence of mesh resolution and the way of computational domain decomposition is evaluated as well. In case of fire smoke, the influence of domain decomposition and mesh resolution is very slight, while in case of aerosol it is more pronounced due to effect of relatively course numerical grid. The results support the hypothesis that the aerosol is suitable to represent the fire smoke for steady-state conditions occurring downstream of the fire in tunnel ventilation tests.
An integrated approach for the analysis and modeling of road tunnel ventilation. Part I: Continuous measurement of the longitudinal airflow profile
