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Avtorstvo: Jana ŠELIH // 1.01 Izvirni znanstveni članek
Leto: 1994
Citat: ŠELIH, Jana, SOUSA, Antonio C. M., BREMNER, Theodore W. Moisture and heat flow in concrete walls exposed to fire. J. eng. mech., Oct. 1994, vol. 120, no 10, str. 2028-2043.
Povzetek: Time-dependent distributions for temperature and moisture content in a concrete wall subjected to fire are determined by a model of heat and mass transfer in porous media. Free-water flow, bound-water diffusion, gas-phase flow, water-vapor diffusion, and thermal energy are accounted for in the model. The governing transient differential equations are discretized by a control-volume formulation reported by Patankar in 1980, and solved in time using a fully implicit scheme. Two different fire exposure curves (namely, standard curve according to ASTM E-119 and a more realistic curve reported by Ellingwood in 1991) are employed in the analysis. The assessment of two simplified models, in which all pore water is assumed to evaporate at 100 oC, is performed by comparing their predictions to the full analysis. For temperature and saturation, the time developments predicted by the two simplified models and by the full analysis present similar trends; however, the simplified models seem to be appropriate only for very preliminary fire safety analysis, since they tend to underestimate temperatures

S kombiniranim numeričnim modelom masnih in toplotnih pretokov, v poroznem materialu smo določili časovno spremenljive razporeditve temperature in vsebnosti vlage v betonski steni, ki je na eni strani izpostavljena požaru. Uporabili smo dva poenostavljena modela, ter njune rezultate primerjali z rezultati celovitega numeričnega modela, ki temelji na enačbah pretoka proste tekoče vode, difuzije vezane vode, pretokov plinaste faze in energetski enačbi, ki upošteva fazne prehode porne vode. Rezultati kažejo, da se lahko poenostavljeni modeli uporabljajo le za preliminarno požarno analizo, saj so temperature, dobljene s poenostavljeno simulacijo, prenizke
Tipologija: 1.01 Izvirni znanstveni članek
COBISS ID 118119 Polni zapis iz sistema COBISS
Vpisal 2001/08/08 19:56