Simulation study on smoke control of urban tunnels with combined smoke exhaust system

Numerical simulations using FDS were carried out to study the smoke control of a 3 300mlength urban tunnels with combined smoke exhaust system.Based on the analysis of the temperature and visibility at 2mheight under different smoke control strategies,it is concluded that when a fire with a HRR of 20 MW breaks out in a urban tunnel with combined smoke exhaust system,it is better to control the longitudinal velocity to be 2.5m/s,and only open the smoke dampers downstream the fire to ensure the safety of people.