Effect of vehicular blocking scene on smoke spread in the longitudinal ventilated tunnel fire

In order to investigate the effect of vehicular blocking scene on the smoke spread in the longitudinal ventilated tunnel fire and improve the effectiveness of smoke control scheme, 30 simulation conditions were carried out. The effect of different blockage area ratio, blockage position, and blockage length on the smoke spread were included. The temperature, velocity, and smoke spread characteristics beneath the tunnel ceiling were analyzed. The results showed that the maximum temperature and smoke spread range beneath the tunnel ceiling was affected significantly by the blockage area ratio. The critical velocity was different when the blockage vehicle was located on upstream or downstream of the fire. When the critical velocity was the same, as the blockage length increased, the maximum temperature beneath the tunnel ceiling decreased at first and then increased gradually.