An analysis of width effects on flame spread in conjunction with concurrent forced flow using a variable B-number
An analysis of width effects on flame spread in conjunction with concurrent forced flow using a variable B-number
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使用可变 B 数分析宽度对火焰蔓延的影响以及并发强制流动
DOI：
10.1016/j.combustflame.2018.05.013
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发表时间：
2018-08
影响因子：
4.4
通讯作者：
Zhang Y.-M.
中科院分区：
文献类型：
--
作者：
Zhao L.-Y.;Fang J.;He X.-Z.;Wang J.-W.;Tao S.-Q.;Zhang Y.-M.
研究了宽度对热厚 PMMA 板上并发强制流动火焰蔓延的影响。根据样品宽度观察到不同的火焰蔓延行为。对于较宽的板坯（宽度≥10cm），火焰蔓延与宽度无关。总燃烧速率随流向位置降低至-0.45次方，这与层流边界层理论预测的非常接近。对于较窄的板（2.5 和 3 厘米），火焰长度和火焰蔓延速率随着宽度的增加而减小。沿流向的总燃烧速率几乎恒定，表明在某个时刻出现了湍流。研究发现，随着火焰的增长，宽度效应从以热量和燃料损失为主变为以空气夹带为主。宽度相关的 B 数是根据测量的间隔距离计算的。对于较宽的板坯，B 数与宽度无关，但由于横向燃料扩散和热损失，对于较窄的板坯，B 数随着样品宽度的减小而减小。燃料横向扩散速率随着样品宽度、流向位置和流速的增加而减小。本研究中的流速对 B 数有轻微影响。预测数据和实验数据之间的良好一致性表明无限宽度假设下的经典火焰蔓延理论可以适用于具有修正B数的有限宽度情况。
Width effects on concurrent forced flow flame spread over thermally-thick PMMA slabs were studied. Different flame spread behaviors were observed depending on the sample width. For wider slabs (width ≥ 10 cm), the flame spread was width-independent. The total burning rate decreased with the streamwise location to the −0.45 power, which was very close to that predicted by the laminar boundary layer theory. For narrower slabs (2.5 and 3 cm), the flame length and flame spread rate decreased with the width. The total burning rate was nearly constant along the streamwise direction, suggesting that turbulence set in at some point. It was found that width effects changed from heat and fuel loss-dominated to air entrainment-dominated as the flame grew. Width-dependentB-numbers were calculated from the measured standoff distances. TheB-number was width-independent for wider slabs but decreased with the decreasing sample width for narrower slabs as a result of lateral fuel diffusion and heat loss. The lateral fuel diffusion rate decreased with the increase of sample width, streamwise location and flow velocity. The flow velocities in this study had a slight effect on theB-number. The good agreement between predicted and experimental data suggested that classical flame spread theories under the infinite width assumption can apply to the finite width case with a modifiedB-number.
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DOI：
10.1016/s0082-0784(00)80701-8
发表时间：
2000
期刊：
--
影响因子：
--
作者：
L. Honda;P. Ronney
通讯作者：
L. Honda;P. Ronney
DOI：
10.1016/s0082-0784(06)80446-7
发表时间：
1991
期刊：
--
影响因子：
--
作者：
L. Zhou;A. Fernandez-Pello
通讯作者：
L. Zhou;A. Fernandez-Pello
影响因子：
1.9
作者：
Kuang‐ Chung Tsai;D. Drysdale
通讯作者：
Kuang‐ Chung Tsai;D. Drysdale
影响因子：
4.4
作者：
Amit Kumar;Hsin-Yi Shih;J. T’ien
通讯作者：
Amit Kumar;Hsin-Yi Shih;J. T’ien
影响因子：
3.7
作者：
J. W. Elder
通讯作者：
J. W. Elder