Influence of sidewall restriction on ceiling temperature distribution induced by double fires in a channel: Experimental and numerical investigations

Abstract

In this paper, the influence of sidewall restriction on the temperature distribution beneath the channel ceiling induced by double fires was experimentally and numerically investigated. Two fire scenarios (center and wall fires) were defined and analyzed. Heat release rate (HRR) and fire separation distance (S) were taken as the primary analysis variables. The results show that with the increase in fire separation distance, the temperature distribution beneath the channel ceiling transitions from a “single-hump” shape to an “M” shape, and the “M” shape temperature distribution appears relatively late for the wall fires. The maximum temperature rise beneath the channel ceiling decreases with increasing S/D, and it is larger under the same HRR and S/D for the wall fires. The temperature decay coefficient K decreases with S/D and increases with HRR, and the temperature decay rate of the wall fire is greater than that of the center fire. Finally, prediction models of the maximum temperature rise and longitudinal temperature decay are proposed for the center and wall fires, respectively. This study is anticipated to contribute novel insights to the design of ceiling fire-resistant materials and fire smoke control in channel-like spaces.