The remote ignition and accelerated flame spread in multiple fires accidents are mainly due to the thermal radiation. The merged flame height and external radiative heat flux distribution of the square fire arrays were investigated numerically. Different burner spacing, total number of burners and heat release rate (HRR) of an individual burner were considered. Results show that the fire plume centerline temperature can be predicted accurately by achieving grid independence on a fine enough grid. A correlation for predicting the merged flame height of the multiple fires is developed involving the number of burners, HRR of each burner and burner spacing. The comparison of calculated and simulated data in this work validated the accuracy of the proposed correlation. The radiative heat flux distributions surrounding the fire array can be divided into two regions, that is, the near- and far-field regions. The total heat release rate of the fire array is shown to be the dominant effect on the radiation distribution throughout the whole region, whilst the burner spacing is shown to only have an effect in the near-field region. To distinguish the two regions, the critical distance of 0.7 ( is the characteristic fire array length) was obtained.

中文翻译：

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方形丙烷火焰阵列融合火焰高度和辐射热通量分布研究

多起火灾事故中的远程点火和火焰加速蔓延的主要原因是热辐射。数值研究了方火阵列的合并火焰高度和外部辐射热通量分布。考虑了不同的燃烧器间距、燃烧器总数和单个燃烧器的热释放率 (HRR)。结果表明，通过在足够精细的网格上实现网格独立，可以准确预测火羽中心线温度。建立了用于预测多火合并火焰高度的相关性，涉及燃烧器的数量、每个燃烧器的 HRR 和燃烧器间距。在这项工作中计算和模拟数据的比较验证了所提出的相关性的准确性。火阵周围的辐射热通量分布可分为近场和远场两个区域。火阵列的总热释放率显示出对整个区域的辐射分布的主要影响，而燃烧器间距显示仅在近场区域有影响。为了区分这两个区域，临界距离为 0.7（是特征火阵列长度）获得。