11. Fire dynamics in tunnels

This paper describes how catastrophic fires have put the focus on fire dynamics in tunnels, especially the influence of ventilation on heat release rate (HRR) and how the fire and the smoke spread within the tunnel. A necessity for a good understanding of fire dynamics in tunnels has become more apparent owing to the occurrence of disastrous fires. This paper discusses the principle phenomena of tunnel fires and fire dynamics. It contains descriptions of fire development in tunnels versus building compartments and the influence of ventilation on the fire (fuel-control versus ventilation-control). It also contains methods to calculate the gas temperatures, the stratification of the smoke, the flame lengths, the incident radiation and fire spread between vehicles.