CFD SIMULATION ON LONGITUDINAL VENTILATION OF TRAIN FIRE IN METROPOLIS RAILWAY TUNNEL

摘要

Longitudinal ventilation has great impact on tunnel fires. In the paper, the numerical relation between length of back-layer and critical ventilation velocity was proposed by CFD numerical analysis. Critical velocities for a metropolis railway tunnel in 4.5MW, 10MW, 16MW, 20MW fire situations were obtained as 1.6426m/s, 1.9929m/s, 2.2587m/s, 2.4548m/s respectively. Based on T.Atkinson's work, the revised equation concerning heat release rate was put forward. This provides the basis for fire prevention and ventilation design in ventilated tunnel fires.