CFD Study On The Interaction Between The Water Sprays And Longitudinal Ventilation In Tunnel Fires

The current research has been conducted in order to study and analyze the interaction of the water spray produced by the water mist system and the smoke layer in tunnel fires where the longitudinal ventilation is operating. The study has been carried out through several computational simulations in the CFD package denominated "Fire Dynamics Simulator”, following the technical features of facility built at Wuhan University. Different scenarios and system configurations were performed following the indications of Wuhan University in order to compare the impact of the droplet diameter, the flow rate and the injection pressure in the flow interaction. Besides, the longitudinal ventilation has been performed in order to obtain the backlayering phenomena for the fire scenarios. The sensitivity analysis has been executed in the nozzles simulations in order to obtain the mesh cell size and the number of water droplets.

As a result, it is possible to argue that the interaction of the water spray in to the smoke layer with the longitudinal ventilation, resulting from the analysis in the smoke layer height, smoke temperature, velocity field, water flux distribution and heat was absorbed by water droplets.