The use of multi-zone modelling for tunnel fires

Abstract

This paper introduces the use of a multi-zone modelling approach for analysing smoke spread in tunnels. The approach suggested in this paper is based on an existing model, i.e., the Multi-Zone Fire model developed for large spaces. The Multi-Zone Fire model has been adapted and modified for tunnel fire scenarios by including features that consider longitudinal ventilation flow, tunnel gradient and tunnel section representations. An evaluation of the model has been conducted through benchmarking against experimental data from the BeNeLux tunnel experiments and the Runehamar tunnel fire experiments. The results from the Multi-Zone Fire model results were also compared against results from the Fire Dynamics Simulator. The results of the benchmarking exercise indicate that the multi-zone approach can be a time-efficient and useful tool for studying tunnel fire dynamics. The Multi-Zone Fire model performs well 50–200 m from the fire for heat release rates of 5–20 MW and moderate longitudinal ventilation flows. The model results are more conservative for the studied scenario with a higher heat release rate.