A Study on the Maximum Temperature of a Ceiling Jet of Asymmetric Dual Strong Plumes in a Naturally Ventilated Tunnel

Abstract

This paper explores the temperature distribution (TD) and maximum temperature (MT) below the ceiling induced by the ceiling jet of an asymmetric dual fire sources in a naturally ventilated tunnel. Considering strong plumes, this study investigates the effects of fire size and spacing of asymmetric dual fire sources on TD and MT. With the same power of fire source, when the size of one of the fire sources increases, the corresponding maximum temperature beneath ceiling decreases. Additionally, the temperature peak below the ceiling shifts from one to two, and the peak temperature of the larger fire source is lower compared to that of smaller one. When the fire sources distance increases, the maximum temperature initially decreases and then increases. Beyond a certain distance, the maximum temperature no longer changes with increasing distance. In this study, we investigated the effect of fire source size and spacing on the MT of the tunnel ceiling for asymmetric dual fire sources. A new model for predicting the MT underneath the tunnel ceiling was developed, taking into account the factors as fire spacing and fire size. The model is able to make effective predictions of the simulation results.

Keywords

• tunnel fire
• asymmetric dual fires
• strong plume
• fire size
• fire spacing
• maximum temperature