Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Numerical modelling of buoyancy-driven natural convection induced by fire in a compartment
The modelling of fire behaviour within a compartment is the basis for predicting smoke movement in builings. The difficulties in the studies of such flow and heat transfer induced by a fire source are related to the modelling of the fundamental physical processes involved, i.e. turbulent stratified natural convection, radiation and combustion. Random factors, such as the location of the fire within the compartment of origin, the eniviromental conditions and the configuration of each door and window also present the modeller with a range of complexities. Simulations have been carried out for fluid flow and heat transfer in a compartment containing a fire source by using an in-house CFD code. Three different turbulence models were considered: the standard kappa-epsilon model and the two low-Reynolds-number kappa-epsilon models of Chien, Jones, and Launder. The analytical expressions of unbounded fire plumes developed by Cox and Chitty were used to model the fire. The results have been compared with the experimental data of Stecker et al. on velocity and temperature at the centreline of the single compartment doorway. Although some agreement has been achieved by using Jones and Lauder's model on temperature profiles, large descrepancies have emerged in velocity predictions, particularly beneath the soffit of the door and window openings with all models. The fixed pressure conditions on the free boundary is considered to be inadequate to satisfy the requirements of calculation accuracy.
Numerical modelling of buoyancy-driven natural convection induced by fire in a compartment
The modelling of fire behaviour within a compartment is the basis for predicting smoke movement in builings. The difficulties in the studies of such flow and heat transfer induced by a fire source are related to the modelling of the fundamental physical processes involved, i.e. turbulent stratified natural convection, radiation and combustion. Random factors, such as the location of the fire within the compartment of origin, the eniviromental conditions and the configuration of each door and window also present the modeller with a range of complexities. Simulations have been carried out for fluid flow and heat transfer in a compartment containing a fire source by using an in-house CFD code. Three different turbulence models were considered: the standard kappa-epsilon model and the two low-Reynolds-number kappa-epsilon models of Chien, Jones, and Launder. The analytical expressions of unbounded fire plumes developed by Cox and Chitty were used to model the fire. The results have been compared with the experimental data of Stecker et al. on velocity and temperature at the centreline of the single compartment doorway. Although some agreement has been achieved by using Jones and Lauder's model on temperature profiles, large descrepancies have emerged in velocity predictions, particularly beneath the soffit of the door and window openings with all models. The fixed pressure conditions on the free boundary is considered to be inadequate to satisfy the requirements of calculation accuracy.
Numerical modelling of buoyancy-driven natural convection induced by fire in a compartment
Wen, J.X. (Autor:in) / Liu, F. (Autor:in) / Karayiannis, T.G. (Autor:in) / Matthews, R.D. (Autor:in)
1996
6 Seiten, 5 Bilder, 14 Quellen
Aufsatz (Konferenz)
Englisch
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