Estimating gas temperatures in large enclosures

A case study is used in this paper to study and analyse drawbacks and advantages of three different numerical fire models when used to model horizontal and vertical gas temperature distributions in a 1200m 2 large enclosure. The three methods are: a CFD model, a two-zone mode l and a multi-layer zone model. This is the first time the three models are used and compared in a large enclosure situation. The problem with using the two-zone model in the studied case is underlying assumption that the hot gas layer has a uniform temperature. Results from both the CFD and the multi-layer zone models shows that there is a vertical temperature distribution and it cannot be modelled in a conventional two-zone model. The multi-layer zone model has several benefits; however, the model requires further development and evaluation.