The numerical simulation of the noncharring pyrolysis process and fire development within a compartment

A pyrolysis model for noncharring solid fuels is presented in this paper. M odel predictions are compared with experimental data for the mass loss rate s of polymethylmethacrylate (PMMA) and very good agreement is achieved. Usi ng a three-dimensional CFD environment, the pyrolysis model is then coupled with a gas-phase combustion model and a thermal radiation model to simulat e fire development within a small compartment. The numerical predictions pr oduced by this coupled model are found to be in very good agreement with ex perimental data. Furthermore, numerical predictions of the relationship bet ween the air entrained into the fire compartment and the ventilation factor produce a characteristic post-flashover linear correlation with constant o f proportionality 0.38 kg/sm(5/2). The simulation results also suggest that the model is capable of predicting the onset of "flashover" and "post-flas hover" type behaviour within the fire compartment. (C) 1999 Elsevier Scienc e Inc. All rights reserved.