CFD simulation validation for tunnel ventilation: A case study from Zentrum am Berg

This study presents the validation of Computational Fluid Dynamics (CFD) simulations for analysing tunnel ventilation efficiency using experimental data obtained at the Zentrum am Berg (ZaB) research facility in Austria. Airflow measurements were conducted in a 100 m dead-end tunnel section equipped with a duct outlet, where velocities were recorded at multiple cross-sections under defined ventilation conditions. The experimental results were compared with numerical simulations performed in Fire Dynamics Simulator (FDS v. 6.9.1). The model reproduced the velocity magnitudes and directional changes with good accuracy, with deviations mostly below 20% and rarely exceeding 30%. Statistical analysis confirmed that measured and simulated values were largely consistent within 95% confidence intervals. The findings demonstrate the reliability of the validated CFD model and its applicability for optimising tunnel ventilation strategies under varying operating scenarios.