Numerical modeling of air velocity distribution in a road tunnel with a longitudinal ventilation system

The paper presents the results of the numerical modeling of the air velocity distribution in a road tunnel. The results were validated by full-scale in situ measurements of air velocity in a normally operated real tunnel. The preparation of the numerical models was preceded by a detailed study on the selected features influencing the structure of modeled flow. Eventually, the results of numerical simulations were compared with those of the measurements. The overall distributions of air velocity were almost the same as the experimental values; slightly larger deviations were observed only at a few points close to the tunnel walls. The variation of the calculated velocity did not exceed 9%, which proved the reliability of the numerical models. The conclusions also include certain recommendations which would be helpful for those who facing the issue of numerical modeling of airflows in tunnels.