含阶梯结构的高层楼梯井内烟气湍流及输运特征量的全局敏感性分析

Global sensitivity analysis on characteristics of smoke turbulence and transport in stairwell shaft with staircase structure in a high-rise building

高层建筑竖井火灾中影响因素众多,并且各因素对高层楼梯井火灾中重要现象、关键数值等的影响大小不一,使得此类火灾中的实验或理论研究成本较高。通过建立全局敏感性分析平台,定量考察了高层楼梯井结构所涉及因素的影响大小,并能够方便地筛选掉对所考察量影响较小的因素,以降低实验或计算成本。使用数值模拟方法,通过CFD软件对包含阶梯几何框架的高层楼梯井结构火灾进行了共计60次工况计算。并且根据计算结果,使用全局参数敏感性分析方法,得出建筑尺寸、热释放速率、环境参数对高层楼梯井内烟气湍流特性及输运特性的敏感性排序。结果表明,火源热释放速率对各输出参数的影响均占38%以上。

The cost for research on shafts in high rise buildings is sometimes unaffordable due to the various factors associated with high-rise buildings and different effects of these factors. In this work, a global sensitivity analysis platform was constructed to investigate the effects of various factors quantitatively and offer a method to lower the computational cost by filtering out those factors with minuscule influence. In total 60 cases of high-rise building stairwell with staircase structures were simulated with numerical methods and then a hierarchy of effects of building structure sizes, heat release rate and ambient parameters on the characteristics of smoke turbulence and transport was derived from the computing results utilizing global sensitivity analysis. The sensitivity analysis results show that the effect ratios of heat release rate of fire source are above 38% to all the responses.