scholarly journals Pool Fire Mass Burning Rate and Flame Tilt Angle under Crosswind in Open Space

2016 ◽  
Vol 135 ◽  
pp. 261-274 ◽  
Author(s):  
Ping Jiang ◽  
Shou-xiang Lu
2021 ◽  
Vol 7 ◽  
Author(s):  
Juan J. Cruz ◽  
Ignacio Verdugo ◽  
Nicolás Gutiérrez-Cáceres ◽  
Felipe Escudero ◽  
Rodrigo Demarco ◽  
...  

The main characteristics of pool fire flames are flame height, air entrainment, pulsation of the flame, formation and properties of soot particles, mass burning rate, radiation feedback to the pool surface, and the amount of pollutants including soot released to the environment. In this type of buoyancy controlled flames, the soot content produced and their subsequent thermal radiation feedback to the pool surface are key to determine the self-sustainability of the flame, their mass burning rate and the heat release rate. The accurate characterization of these flames is an involved task, specially for modelers due to the difficulty of imposing adequate boundary conditions. For this reason, efforts are being made to design experimental campaigns with well-controlled conditions for their reliable repeatability, reproducibility and replicability. In this work, we characterized the production of soot in a surrogate pool fire. This is emulated by a bench-scale porous burner fueled with pure ethylene burning in still air. The flame stability was characterized with high temporal and spatial resolution by using a CMOS camera and a fast photodiode. The results show that the flame exhibit a time-varying propagation behavior with a periodic separation of the reactive zone. Soot volume fraction distributions were measured at nine locations along the flame centerline from 20 to 100 mm above the burner exit using the auto-compensating laser-induced incandescence (AC-LII) technique. The mean, standard deviation and probability density function of soot volume fraction were determined. Soot volume fraction presents an increasing tendency with the height above the burner, in spite of a local decrease at 90 mm which is approximately the position separating the lower and attached portion of the flame from the higher more intermittent one. The results of this work provide a valuable data set for validating soot production models in pool fire configurations.


Author(s):  
S. Sudheer ◽  
S. V. Prabhu

Characterization of pool fires in the presence of cylindrical containers is highly relevant for various applications. A cylindrical container is idealized as a circular pipe packed with insulating material inside. Open pool fire experiments are conducted with a cylindrical container located at the center. The pool fire diameters considered were 0.5 m, 0.7 m and 1.0 m with diesel as the fuel. The cylindrical containers are made of stainless steel 304L. The outer diameters of the pipes are 114 mm, 168 mm and of thickness 8.6 mm, 7.1 mm respectively. The effect of blockage ratio on the mass burning rate for vertical and horizontal orientations of 168 mm cylindrical container is studied. It is observed that there is no significant change in mass burning rate due to the blockage effect. Temperatures are measured at various locations inside the pipes and at the center of the insulation. It is observed that the temperatures along a plane perpendicular to the axis are uniform when the pipes are vertically oriented. IHCP 1D code is applied to estimate the incident heat flux on to the bodies when immersed in open pool fires with different orientations.


Author(s):  
Yi Zeng ◽  
Jun Fang ◽  
Ran Tu ◽  
Jinjun Wang ◽  
Yongming Zhang

This paper presents results of different burning rates of small-scale ethanol pool fires at pressures of 0.6∼1.0 atm in closed and open space. Experiments were performed using a square burner of side length of 4 cm under two different conditions: one was taken in a closed low air pressure cabin (0.5 m3, the interior pressure ranges from 0.6–1.0 atm); another was taken in open space respectively in Hefei (air pressure: 1.0 atm) and Lhasa (air pressure: 0.66 atm). The pool fire characteristics including the burning rate, the axial temperature and pulsation frequency of flame were measured. In closed space, the burning rate, flame temperature, and pulsation frequency of small-scale ethanol pool fires decreased with the decreasing pressure, while in open space they increased when the air pressure reduced. As a result of different ambient conditions and oxygen depletion, the burning rate, flame temperature and pulsation frequency were lower at lower air pressure in closed space but were higher at higher air pressure in open space.


2017 ◽  
Vol 113 ◽  
pp. 1004-1010 ◽  
Author(s):  
Qiuju Ma ◽  
Quanyi Liu ◽  
Hui Zhang ◽  
Runhe Tian ◽  
Junjian Ye ◽  
...  

Author(s):  
Qiuju Ma ◽  
Quanyi Liu ◽  
Runhe Tian ◽  
Junjian Ye ◽  
Rui Yang ◽  
...  

Fire safety is critical for safety of airplane operation. During an emergency landing, airplane goes through dramatic external pressure change from cruise altitude to sea level, considering the impact caused by low pressure atmosphere. The objective of this work is to examine the effect of dynamic pressure on the behavior of a horizontally burning diffusion flame over a pool fuel surface based on experimental approach. The experiments were conducted in a large-scale altitude chamber of size 2 m × 3 m × 4.65 m. The pressure rise process was examined under different dynamic pressures from respectively 38 kPa, 64 kPa and 75 kPa to 90 kPa with various pressure rise rates of 100 Pa/s, 150 Pa/s, 200 Pa/s, 250 Pa/s and 300 Pa/s, which is to simulate the airplane landing process from different altitudes. The whole system of the altitude chamber is of unique capability that the pressure in the chamber can be exactly controlled by a powerful pressure controlling system, and the oxygen concentration can maintain at the level about 20%, which are achieved through controlling inlet air flow for oxygen level and outlet gas flow for pressure (static or dynamic) level. A round steel fuel pans of 34 cm in diameter and 15 cm in height were chosen for the pool fire tests. The fuel pan was filled with 99% pure liquid n-Heptane. Cold water is added beneath the fuel layer to cool the pan and minimize the temperature rise in the fuel. Parameters such as mass, mass burning rate, chamber pressure were measured. The results of those tests demonstrated the significant impact to fire behaviors caused by high altitude or low pressure atmosphere.


Author(s):  
Qiuju Ma ◽  
Quanyi Liu ◽  
Runhe Tian ◽  
Junjian Ye ◽  
Rui Yang ◽  
...  

This research aims to investigate the effect of ambient pressure on the burning rate and heat release rate (HRR) of n-heptane pool fire. The experiments were performed in a large-scale altitude chamber of size 2 m×3 m×4.65 m under series of pressure, 24kpa, 38 kPa, 64 kPa and 75 kPa to 90 kPa. A round steel fuel pans of 34 cm in diameter and 15 cm in height was chosen for the pool fire tests. The fuel pan was filled with 99% pure liquid n-Heptane. Experimental results show that the burning rate increases rapidly after ignition until it reaches to the peak, and then maintains at a relatively stable stage. It decreases gradually until the flame extinguishes. The burning time is longer at lower pressure. The mean mass burning rate at the steady burning stage increases exponentially with pressure as ṁ ∼ Pα, with α = 0.68. HRR curve has a similar trend with the burning rate. The maximum HRR increases from 27kW to 62kW as the pressure rises from 24kPa to 90kPa. It is concluded that the ambient pressure has a significant effect on the fire heat release rate, and will further influent on other fire parameters.


Author(s):  
Prabhakar Venkateswaran ◽  
Andrew D. Marshall ◽  
Jerry M. Seitzman ◽  
Tim C. Lieuwen

This work describes measurements and analysis of the turbulent consumption speeds, ST,GC, of H2/CO fuel blends. We report measurements of ST,GC at pressures and normalized turbulence intensities, u′rms/SL,0 up to 20 atm and 1800, respectively for a variety of H2/CO mixtures and equivalence ratios. In addition, we present correlations of these data using laminar burning velocities of highly stretched flames, SL,max, derived from quasi-steady leading points models. These analyses show that SL,max can be used to correlate data over a broad range of fuel compositions, but do not capture the pressure sensitivity of ST,GC. We suggest that these pressure effects are more fundamentally a manifestation of non-quasi-steady behavior in the mass burning rate at the flame leading points.


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