干挂石材幕墙火蔓延数值模拟研究

摘要

采用数值模拟技术研究了干挂石材幕墙发生燃烧情况下的火蔓延及羽流特点.通过外部高温辐射源点燃了具有4cm厚PMMA保温层但保温材料和外层钢板间存在2cm缝隙下的干挂石材幕墙,对模拟结果的温度场、速度场和热释放速率的分析表明其火蔓延速度较泡沫壁面低,但碳化区形状规则,蔓延路径清晰;虽然热释放速率低,但相对而言火焰高度较高,火焰宽度较小,而且其火羽流呈现点火源的特点.%CFD numerical simulation is performed to investigate the flame speed mechanism over a stone curtain wall. The PMMA thermal insulating layer of the wall is 4 cm thickness, and a 2cm gap exists between the thermal insulating layer and the outside steel plate. An external hot plane ignites the PMMA inside the stone curtain wall.The results of the simulation show that the flame speed over the stone curtain wall is smaller than that of vertical PMMA surface. The pyrolysis zone is of regular shape and extends in clear way. The flame height is high with respected to its low heat release rate.