摘要
通过实体小室轰燃试验,比较BFD曲线参数估计法和FDS场模拟在轰燃预测上的可靠性。采用相关系数法比较BFD曲线参数估计法和FDS场模拟对室内温度变化预测的可靠性;通过偏差均方根比较了这两种预测方法对室内最高温度预测的可靠性。结果表明,BFD曲线参数估计法对轰燃发生时的室内温度变化的预测结果接近火灾实际情况(平均相关系数为0.920 1),但对未发生轰燃时的预测的可靠性较差(相关系数为0.313 8)。通过两种不同网格密度(网格大小分别为0.13m3和0.053m3,总网格数分别为45 000和360 000)的FDS场模拟发现,采用细网格时FDS场模拟对温度变化的预测的可靠性较好(相关系数为0.881 8)。轰燃发生和未发生两种条件下,FDS场模拟对室内最高温度的预测能力都优于BFD曲线参数估计法,而网格加密对提高FDS场模拟预测能力的影响不明显。通过对火灾时房间内温度预测的比较,可得到不同模型对轰燃发生时间和强度预测的可靠性,这对建筑结构安全和人员逃生具有重要意义。
The present paper is aimed at reporting our analysis on the experimental data and numerical simulation test results on the compartment fire flashover through comparison between a parametric fire（BFD curve method） and a field-simulated model（FDS model）.It is well known that with the increasing use of simulated models in fire prevention,it has become more and more important to truly understand the limitations and applicability of the above said simulated models.To validate such models,we have established a compartment flame-flashover test and measured its temperatures in 3 different test conditions.By introducing the temperature-time curve correlation coefficient,it can be found that BFD curve forecasting,the average correlation coefficient is worked out to be equal to 0.920 1,though unreliable on no-flashover fire,for which it can only be expected at about 0.313 8.Moreover,a method known as root-mean-square of the deviation has also to be used to validate the predictive capability of the maximum temperature between two models.A direct comparison of the deviation root-mean-squares proves BFD model is less efficient in its predictive capability than FDS curve.Therefore,for FDS simulation,two grid resolutions are to be used,which are of 45 000 and 360 000 cells respectively.As a result,even the more efficient one is just endowed with a little better predictive power in terms of comparisons.Therefore,in the final analysis,BFD curve should be taken as a better version with greater applicability,though limited on no-flashover case,while FDS model has a wider use,though more calculation time is needed as compared with BFD curve.
出处
《安全与环境学报》
CAS
CSCD
2008年第5期141-145,共5页
Journal of Safety and Environment
基金
国家"十一五"科技支撑项目(2006BAK06B042006BAK01B03-1)
关键词
燃烧学
室内轰燃
BFD曲线
FDS场模拟
combustion science, compartment flashover fire, BFD curve, FDS field simulation
