Numerical studies on performance evaluation of tunnel ventilation safety systems

The performance of tunnel safety systems for fire protection and ventilation provision is evaluated using Computational Fluid Dynamics (CFD). Ventilation safety systems commonly used in tunnels are reviewed first. The safety aspects related to tunnel fire and ventilation are then discussed. Air flow induced by an accidental vehicular fire in a tunnel is simulated using CFD. Based on the results, performances of different safety systems are evaluated and compared. Systems considered are longitudinal, semi-transverse, transverse, partial transverse, and combined longitudinal and semi-transverse ventilation systems. Furthermore, sensitivity analyses on the effects of the grid size, and number of iterations on the required computing time and accuracy of the results are carried out. (C) 2003 Elsevier Science Ltd. All rights reserved.