Suzuki Sayaka, Manzello Samuel L
National Research Institute of Fire and Disaster (NRIFD), Chofu, Tokyo, 182-8508, Japan.
National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899-8665, USA.
Fire Technol. 2020;57(2). doi: 10.1007/s10694-020-01018-5.
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.
火灾蔓延通过辐射、火焰接触和火旋风发生。虽然已知火旋风阵雨是引发远离主火前沿的燃料着火的飞火成因，但对于短距离飞火而言，主火的辐射可能在火旋风引发的点火过程中起作用。过去许多研究都集中在对火灾蔓延的单一影响上，而对耦合效应了解甚少。通过使用新开发的实验方案，研究了辐射热通量和火旋风阵雨对燃料床点火过程的耦合效应。新开发的方案包括在与风力设施相连的火旋风发生器的现有实验装置中增加一个辐射板。实验是在施加的风场下进行的，因为风是大型户外火灾蔓延过程中的一个关键参数。结果表明，在风速为6米/秒时，辐射热通量对火旋风引发的点火起重要作用，而在风速为8米/秒时观察到的影响很小。
