Fire Safety Science Digital Archive

This work considers the application of participating media models, used in conjunction with the discrete transfer method, for predicting thermal radiation fluxes from fires. The models considered differ in their generality, sophistication, accuracy and computational cost, and are assessed in terms of their ability to predict radiative transfer in idealized situations, as well as from fires. It is concluded that the implementation of simple participating media models, based on the grey gas assumption, must be treated with caution due to convergence problems. Use of models based on the banded grey gas, TTNH, wide and narrow band approaches yield satisfactory results for fire applications. Computations performed using Cartesian meshes demonstrate that the TTNH and banded grey gas models give speed-up factors of one and two orders of magnitude relative to more complex approaches, although this level of performance is reduced when more complex meshes are employed.