Modelling CO production in vitiated compartment fires

Abstract

Strategies for the modelling of CO production in compartment fires, based on laminar flamelet relationships, derived from computations of vitiated laminar diffusion flames, and on a simplified two-step eddy dissipation model, are identified and compared. A flamelet library is constructed which incorporates the parametric variation of ambient oxygen concentration and temperature. Expected departures from mixing controlled burning, arising in regions like hot ceiling layers, for example, are assessed with reference to homogeneous plug flow calculations, initiated from peak CO conditions drawn from the laminar flame computations. Implementation of the two approaches in CFD simulations of ventilation-controlled compartment fires using the SOFIE code suggest that both offer the prospect of reliable CO prediction, given a measure of calibration. Copyright © International Association for Fire Safety Science.