The maximum temperature of buoyancy-driven smoke flow beneath the ceiling in tunnel fires

2011 ◽  
Vol 46 (4) ◽  
pp. 204-210 ◽  
Author(s):  
Ying Zhen Li ◽  
Bo Lei ◽  
Haukur Ingason
Keyword(s):  
Maximum Temperature ◽  
Tunnel Fires ◽  
Smoke Flow

Study on the heat exhaust coefficient and smoke flow characteristics under lateral smoke exhaust in tunnel fires

2019 ◽  
Vol 43 (7) ◽  
pp. 857-867 ◽  
Author(s):  
Zhisheng Xu ◽  
Qiulin Liu ◽  
Lu He ◽  
Haowen Tao ◽  
Jiaming Zhao ◽  
...  
Keyword(s):  
Flow Characteristics ◽  
Tunnel Fires ◽  
Smoke Flow

scholarly journals Experimental Investigation on the Discharge of Pollutants from Tunnel Fires

2020 ◽  
Vol 12 (5) ◽  
pp. 1817
Author(s):  
Lihua Zhai ◽  
Zhongxing Nong ◽  
Guanhong He ◽  
Baochao Xie ◽  
Zhisheng Xu ◽  
...  
Keyword(s):  
Laser Sheet ◽  
Longitudinal Velocity ◽  
Release Rates ◽  
Layer Height ◽  
Tunnel Fires ◽  
Smoke Flow ◽  
Longitudinal Ventilation ◽  
Toxic Gases ◽  
Smoke Layer ◽  
Series Of Experiments

Many pollutants are generated during tunnel fires, such as smoke and toxic gases. How to control the smoke generated by tunnel fires was focused on in this paper. A series of experiments were carried out in a 1:10 model tunnel with dimensions of 6.0 m × 1.0 m × 0.7 m. The purpose was to investigate the smoke layer thickness and the heat exhaust coefficient of the tunnel mechanical smoke exhaust mode under longitudinal wind. Ethanol was employed as fuel, and the heat release rates were set to be 10.6 kW, 18.6 kW, and 31.9 kW. The exhaust velocity was 0.32–3.16 m/s, and the longitudinal velocity was 0–0.47 m/s. The temperature profile in the tunnel was measured, and the buoyant flow stratification regime was visualized by a laser sheet. The results showed that the longitudinal ventilation leads to a secondary stratification of the smoke flow. In the ceiling extract tunnel under longitudinal ventilation, considering the research results of the smoke layer height and the heat exhaust coefficient, a better scheme for fire-producing pollutants was that an exhaust velocity of 1.26–2.21 m/s (corresponding to the actual velocity of 4.0–7.0 m/s) should be used. The longitudinal velocity should be 0.16–0.32 m/s (corresponding to the actual velocity of 0.5–1.0 m/s).

Study on the maximum temperature and temperature decay in single-side centralized smoke exhaust tunnel fires

2022 ◽  
Vol 172 ◽  
pp. 107277
Author(s):  
Liangliang Tao ◽  
Yanhua Zeng ◽  
Jie Li ◽  
Guichang Yang ◽  
Yong Fang ◽  
...  
Keyword(s):  
Maximum Temperature ◽  
Tunnel Fires ◽  
Temperature Decay ◽  
Single Side

Control of smoke flow in tunnel fires

1995 ◽  
Vol 25 (4) ◽  
pp. 305-322 ◽  
Author(s):  
Yasushi Oka ◽  
Graham T. Atkinson
Keyword(s):  
Tunnel Fires ◽  
Smoke Flow

Effect of blockage ratio on the maximum temperature under the ceiling in tunnel fires

2012 ◽  
Vol 31 (3) ◽  
pp. 245-257 ◽  
Author(s):  
Liming Li ◽  
Xudong Cheng ◽  
Yu Cui ◽  
Wenhui Dong ◽  
Zhibin Mei
Keyword(s):  
Maximum Temperature ◽  
Blockage Ratio ◽  
Tunnel Fires

scholarly journals Investigation on Smoke Flow in Stairwells induced by an Adjacent Compartment Fire in High Rise Buildings

2019 ◽  
Vol 9 (7) ◽  
pp. 1431 ◽  
Author(s):  
Jun Zhang ◽  
Jingwen Weng ◽  
Tiannian Zhou ◽  
Dongxu Ouyang ◽  
Qinpei Chen ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Three Dimensional ◽  
Factor H ◽  
Maximum Temperature ◽  
Vertical Temperature ◽  
Location Factor ◽  
Index Model ◽  
Smoke Flow ◽  
Vertical Temperature Distribution ◽  
Fire Location

The aim of this study was to evaluate the transport phenomena of smoke flow and vertical temperature distribution in a 21-story stairwell with multiple fire locations and openings. A large eddy simulation (LES) method was used to model the smoke flow in a stairwell model with a set of simulation parameters, wherein the fire heat release rate (HRR) and fire location were varied. Based on the results, a wall attachment effect was found in three-dimensional figures. Moreover, with an increase in the fire HRR, the effects were more pronounced. The simulation results verified that the vertical temperature distribution is an index model with a natural logarithm, where the pre-finger factor and attenuation coefficient increase considerably in accordance with an increase in the fire HRR. Moreover, there was a decrease in the maximum temperature (Tm) with an increase in the fire location factor (h*) due to the upward thermal smoke. Moreover, heat mainly accumulates in the area above a fire source. However, h* has a slight influence on the time required to reach Tm within the range of 53–64 s. Furthermore, the direction of the airflow at each side opening in the stairwell varied in accordance with the variation in the fire location changes, and a regular calculation was carried out.

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