ABSTRACT
The most recent technique to study the behavior of tunnel ventilation is computational fluid
dynamics (CFD). This approach is capable of modeling the multi-dimensional, obstructed
and non-obstructed tunnels of arbitrary geometry. This paper addressed the methodology
improvement for the design of ventilated road tunnels using CFD technique. A
comprehensive CFD simulation has been carried out to examine the velocity, pressure and
temperature distributions in the main scenario of tunnel ventilation in case of normal and
halted traffic. The predicted results are used to enhance the design and evaluate the
ventilation system capability to fulfill the required thermal environment inside the tunnel.
The base design of tunnel ventilation system was modified to avoid the unsafe regions in
the tunnel where the effects of carbon monoxide (CO) are hazard.