Studies on ceiling maximum thermal smoke temperature and longitudinal decay in a tunnel fire with different transverse gas burner locations

Abstract

A series of experiments are conducted to analyze and discuss ceiling maximum thermal smoke temperature and longitudinal decay along the centerline of the tunnel with different transverse fire source locations. The size of scale model tunnel is 72m (length)×1.5m (width)×1.3m (height). Three transverse gas burner locations were considered, such as Location A (close to the wall), Location B (near the wall), Location C (centerline of the tunnel), the corresponding distance between the centerline of the gas burner and the tunnel wall are 0.2m, 0.475mand0.75m, respectively. It was found that Li model underestimates the maximum thermal smoke temperature beneath the ceiling with different transverse fire source locations. Thus a dimensionless coefficient λ is put forward to consider the effect of different horizontal fire source location on thermal smoke temperature profile. The predictions by the modified model of this work agree well with the measured data in the maximum thermal smoke considering different transverse fire source locations. The revised thermal smoke temperature decay formula along the centerline of the tunnel is introduced, and the deduced values of coefficient Kcdown are correlated linearly with transverse fire location.