The Variability of Critical Mass Loss Rate at Auto-Extinction
The Variability of Critical Mass Loss Rate at Auto-Extinction
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DOI：
10.1007/s10694-020-01002-z
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发表时间：
2020-05
期刊：
影响因子：
3.4
通讯作者：
Snorri Már Arnórsson;R. Hadden;A. Law
中科院分区：
文献类型：
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作者：
Snorri Már Arnórsson;R. Hadden;A. Law
木材可能发生自动熄灭的条件对于大规模木结构特别重要，因为在火灾期间，结构木材的元件暴露或变得暴露。使用95毫米的木材立方体上的实验，自动消光的样品取向的灵敏度，和施加的流动通过样品的表面进行了研究。结果发现，垂直和水平方向之间的燃烧速率的变化是8%，但在垂直方向的样品，自动熄灭发生在一个较高的质量损失值。结果发现，虽然灭绝的临界质量损失率是相对一致的，在一个给定的方向（变异系数，16%），在灭绝的时间，从而消耗的木材的总质量的变化是显着的（变异系数，40%）。消光的临界质量损失与样品表面流速的平方有关。
The conditions under which auto-extinction of timber can occur are of particular importance for mass timber structures where elements of structural timber are exposed, or become exposed, during a fire. Using experiments on 95 mm cubes of timber, the sensitivity of auto-extinction to sample orientation, and an imposed flow across the surface of the sample was investigated. It was found that the variation in burning rate between the vertical and horizontal orientation was 8% but that, for samples in a vertical orientation, auto-extinction occurred at a higher value of mass loss. It was found that while the critical mass loss rate for extinction was relatively consistent in a given orientation (coefficient of variation, 16%), the variability in the time to extinction, and thus the total mass of timber consumed, was significant (coefficient of variation, 40%). Critical mass loss for extinction was linked to the square of the flow velocity at the surface of the sample.