scholarly journals A strategy to develop engineering upward flame-spread evaluation methodology based on the linearized flame height approximation.

1995 ◽  
Vol 15 (1/2) ◽  
pp. 17-28 ◽  
Author(s):  
Yuji Hasemi ◽  
Noboru Yasui
Keyword(s):  
Flame Spread ◽  
Evaluation Methodology ◽  
Flame Height ◽  
Upward Flame Spread

scholarly journals Large scale experimental study on the fire hazard of buildings’ U-shape façade wall geometry

2017 ◽  
Vol 23 (4) ◽  
pp. 455-463 ◽  
Author(s):  
Weigang YAN ◽  
Lin JIANG ◽  
Weiguang AN ◽  
Yang ZHOU ◽  
Jinhua SUN
Keyword(s):  
Theoretical Analysis ◽  
Flame Spread ◽  
Large Scale ◽  
Fire Hazard ◽  
Residential Building ◽  
Flame Height ◽  
Geometrical Factor ◽  
Insulation Material ◽  
Upward Flame Spread ◽  
Wall Geometry

Buildings have U-shape façade designs for certain purposes such as lighting. However, such designs may lead to a higher fire hazard. In this paper, large scale experiments of upward flame spread over XPS insulation material were conducted to investigate the fire hazard of building’s U-shape façade wall geometry. Comparison to previous labora­tory scale experiments were also presented. Theoretical analysis was performed to reveal the mechanism of the U-shape geometry’s influences. It is found that such geometry design would increase the fire hazard of buildings: flame spread rate and flame height increased with U-shape’s geometrical factor. The results agreed with theoretical analysis. It is ex­pected that the buildings’ U-shape façade wall geometry would greatly benefit flame spread for full scale applications and increase the fire hazard. Thus engineers should be careful with such façade wall designs, especially for residential building designs.

scholarly journals On the flame height definition for upward flame spread

2007 ◽  
Vol 42 (5) ◽  
pp. 384-392 ◽  
Author(s):  
J.L. Consalvi ◽  
Y. Pizzo ◽  
B. Porterie ◽  
J.L. Torero
Keyword(s):  
Flame Spread ◽  
Flame Height ◽  
Upward Flame Spread

Experimental study of the width effects on self-induced buoyant blow off in upward flame spread over thin fabric fuels

2019 ◽  
Vol 90 (11-12) ◽  
pp. 1404-1413 ◽  
Author(s):  
Guoqing Zhu ◽  
Yunji Gao ◽  
Guoqiang Chai ◽  
Jinju Zhou ◽  
Shuai Gao
Keyword(s):  
Flame Spread ◽  
Flame Length ◽  
Flame Height ◽  
Spread Rate ◽  
Fire Control ◽  
Constant Length ◽  
Flame Spreading ◽  
Upward Flame Spread ◽  
Flame Thickness ◽  
Induced Velocity

In this paper, a series of upward flame spreading experiments were conducted on thin flax fabric with various widths ranging from 3.0 to 8.0 cm and length of 1.6 m. Symmetric ignition at the entire bottom edge of samples led to two-sided upward flame growth initially. A very interesting behavior of flame blown off was observed in upward flame spreading and an explanation was provided based on the increased buoyancy-induced velocity at the flame base. When the sample width is 6 cm or less, the flame length increases to a critical value and, correspondingly, the buoyancy-induced velocity reaches the blow off velocity, which results in a flame being blown off on one side. The remaining flame on the other side would shrink in length and propagate to the end of the sample with an asymptotically constant length and steady spread rate. For samples wider than 6 cm, the two-sided flame continues to spread to the end of samples and the self-induced blow off phenomenon is not observed. Moreover, the width effects on the flame height, flame thickness and flame spread rate are analyzed and explained in this paper. The results of this study may help advance better understanding of flame blow off behaviors over solid surfaces and have implications concerning fire control of flame spread over solid fuels.

Flame height correlation and upward flame spread modelling

2002 ◽  
Vol 26 (6) ◽  
pp. 279-287 ◽  
Author(s):  
Kuang- Chung Tsai ◽  
Dougal Drysdale
Keyword(s):  
Flame Spread ◽  
Flame Height ◽  
Upward Flame Spread

Experimental study of welding region effects on upward flame spread over textile membranes

2018 ◽  
Vol 89 (10) ◽  
pp. 2041-2053 ◽  
Author(s):  
Yunji Gao ◽  
Guoqing Zhu ◽  
Mengwei Yu ◽  
Feng Guo ◽  
Yu Xia ◽  
...  
Keyword(s):  
Flame Spread ◽  
Ignition Time ◽  
Flame Temperature ◽  
Air Entrainment ◽  
Flame Length ◽  
Flame Height ◽  
Spread Rate ◽  
Pyrolysis Gas ◽  
Upward Flame Spread ◽  
Pyrolysis Spread Rate

Textile membranes are used widely as a main architectural material in membrane structure buildings. However, very few studies have been conducted to investigate the flame spread characteristics of textile membranes, especially in the case of upward flame spread. In this paper, the effects of welding region on upward flame spread were investigated experimentally using sample sheets of textile membranes 60 cm tall and 6 cm wide with and without welding region. The corresponding observations are as follows: the width of flame with welding region is narrower than that without welding region; flame height, pyrolysis height, preheating length, flame length, and pyrolysis spread rate decrease significantly in the presence of a welding region, while ignition time increases; flame temperature decreases in the presence of a welding region, and temperature along the welding region is higher than that near the edge. The welding region effects are as follows: in presence of a welding region, the thickness of welding region increases and, accordingly, ignition time shows an increase, leading to relatively low pyrolysis gas generated per unit time and relatively less heat released; in addition, a relatively larger pyrolysis gas concentration gradient over the width for welding membranes results in a relatively stronger air entrainment occurring at the sample sides, taking away part of the heat flux and narrowing the flame width. Thus, the presence of a welding region has negative effects of increasing ignition time and reducing preheating length on upward flame spread over textile membranes, eventually decreasing the pyrolysis spread rate.

Experimental study of the non-monotonous moisture effect on upward flame spread over cotton fabric

2017 ◽  
Vol 88 (20) ◽  
pp. 2379-2394 ◽  
Author(s):  
Yunji Gao ◽  
Guoqing Zhu ◽  
Hui Zhu ◽  
Yu Xia
Keyword(s):  
Moisture Content ◽  
Cotton Fabric ◽  
Flame Spread ◽  
Flame Temperature ◽  
Flame Height ◽  
Infinite Length ◽  
Spread Rate ◽  
Negative Effects ◽  
Moisture Effect ◽  
Upward Flame Spread

The present paper studies the moisture effect on upward flame spread over cotton fabric by performing experiments using 0.245 mm thick, 180 cm tall and 10 cm wide sample sheets with moisture content ranging from 0% to 18%. As the moisture content increases, the flame height, pyrolysis height, burnout height, pyrolysis length and spread rate show the same trend, first increasing and then decreasing. The maximum value is observed in the case of the 2% moisture content samples. Furthermore, at an infinite length of fabric fuel, the upward flame propagation would reach an asymptotic steady state with constant pyrolysis length and spread rate. Finally, a higher moisture content corresponds to a lower flame temperature. For upward flame spread, the moisture content has the negative effects of increasing the thermal inertia parameters and reducing the flame temperature and heat feedback; simultaneously, the positive effect is that the moisture can enlarge the flame size and the effective preheating length. The combined effects of positive and negative effects result in the non-monotonous trend in the pyrolysis spread rate.

scholarly journals Thermodynamic and Kinetic Characteristics of Combustion of Discrete Polymethyl Methacrylate Plates with Different Spacings in Concave Building Facades

Polymers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 167
Author(s):  
Weiguang An ◽  
Lujun Peng ◽  
Minglun Cai ◽  
Kaiyang Hu ◽  
Song Li ◽  
...  
Keyword(s):  
Polymethyl Methacrylate ◽  
Flame Spread ◽  
Structure Factor ◽  
Turning Point ◽  
Fire Risk ◽  
Flame Height ◽  
Hazard Evaluation ◽  
Spread Rate ◽  
Building Facades ◽  
Flame Spread Rate

Polymethyl methacrylate plates are widely applied to buildings, producing significant fire hazards. It lacks a theoretical basis for the fire risk assessment of polymethyl methacrylate in concave building facades. Therefore, experimental methods are used to investigate combustion characteristics of discrete polymethyl methacrylate plates in a concave building facade. Influences of fuel coverage and structure factor are investigated, which is scant in previous works. When structure factor is invariable, average flame height increases first and then decreases as fuel coverage increases, and the turning point is between 0.64 and 0.76. In total, three different patterns of pyrolysis front propagation are first observed for different fuel coverages. Flame spread rate first increases and then decreases as fuel coverage rises, and the turning point is also between 0.64 and 0.76. When fuel coverage is invariable, the flame spread rate first increases and then decreases with increasing structure factor, and the turning point is 1.2. A model for predicting the flame spread rate of discrete polymethyl methacrylate is also developed. The predicted values are consistent with experimental results. Fuel spread rate of discrete polymethyl methacrylate rises as the fuel coverage increases. The above results are beneficial for thermal hazard evaluation and fire safety design of polymethyl methacrylate used in buildings.

scholarly journals Influence of U-shaped structure on upward flame spread and heat transfer behaviors of PMMA used in building thermal engineering

2020 ◽  
Vol 22 ◽  
pp. 100794
Author(s):  
Weiguang An ◽  
Xiangwei Yin ◽  
Minglun Cai ◽  
Yanhua Tang ◽  
Qing Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Flame Spread ◽  
Thermal Engineering ◽  
Upward Flame Spread

Experimental Study of Upward Flame Spread over Discrete Weathered Wood Chips

2021 ◽  
pp. 1-12
Author(s):  
Biao Zhou ◽  
Kai Wang ◽  
Yanyi Liuchen ◽  
Yuhang Li ◽  
Xukun Sun ◽  
...  
Keyword(s):  
Experimental Study ◽  
Flame Spread ◽  
Wood Chips ◽  
Upward Flame Spread
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