Fire spread occurs via radiation, flame contact, and firebrands. While firebrand showers are known to be a cause of spot fires which ignite fuels far from the main fire front, in the case of short distance spot fires, radiation from the main fire may play a role for firebrand induced ignition processes. Many past investigations have focused on singular effects on fire spread, and little is known about coupled effects. The coupled effect of radiative heat flux and firebrand showers on ignition processes of fuel beds is studied by using a newly developed experimental protocol. The newly developed protocol includes the addition of a radiant panel to the existing experimental setup of a firebrand generator coupled to a wind facility. Experiments were performed under an applied wind field, as the wind is a key parameter in large outdoor fire spread processes. Results show that radiant heat flux plays an important role for ignition by firebrands under 6 m/s while little effect was observed under 8 m/s.

中文翻译：

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研究辐射热通量和火焰阵雨对燃料床点火的耦合影响

火势蔓延通过辐射、火焰接触和火把发生。虽然已知火点阵雨是点燃远离主火锋的燃料的点火的原因，但在短距离点火的情况下，主火的辐射可能对火点引起的点火过程起作用。过去的许多调查都集中在对火势蔓延的单一影响上，而对耦合效应知之甚少。使用新开发的实验方案研究了辐射热通量和火点阵雨对燃料床点火过程的耦合影响。新开发的协议包括在与风力设施耦合的火标发电机的现有实验装置中添加辐射板。实验是在外加风场下进行的，因为风是大型室外火灾蔓延过程中的一个关键参数。结果表明，辐射热通量在 6 m/s 下对火把点火起重要作用，而在 8 m/s 下几乎没有观察到影响。