scholarly journals Estimating the amount of water required to extinguish wildfires under different conditions and in various fuel types

2012 ◽  
Vol 21 (5) ◽  
pp. 525 ◽  
Author(s):  
Rickard Hansen
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Combustion Zone ◽  
Unit Length ◽  
Water Flow Rate ◽  
Flame Length ◽  
Low Intensity ◽  
Surface Fires ◽  
Fire Front

In wildland fires where water is used as the primary extinguishing agent, one of the issues of wildfire suppression is estimating how much water is required to extinguish a certain section of the fire. In order to use easily distinguished and available indicators, the flame length and the area of the active combustion zone were chosen as suitable for the modelling of extinguishing requirements. Using Byram’s and Thomas’ equations, the heat release rate per unit length of fire front was calculated for low-intensity surface fires, fires with higher wind conditions, fires in steep terrain and high-intensity crown fires. Based on the heat release rate per unit length of fire front, the critical water flow rate was calculated for the various cases. Further, the required amount of water for a specific active combustion zone area was calculated for various fuel models. Finally, the results for low-intensity surface fires were validated against fire experiments. The calculated volumes of water can be used both during the preparatory planning for incidents as well as during firefighting operations.

Corrigendum to: Estimating the amount of water required to extinguish wildfires under different conditions and in various fuel types

2012 ◽  
Vol 21 (6) ◽  
pp. 778
Author(s):  
Rickard Hansen
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Combustion Zone ◽  
Unit Length ◽  
Water Flow Rate ◽  
Flame Length ◽  
Low Intensity ◽  
Surface Fires ◽  
Fire Front

In wildland fires where water is used as the primary extinguishing agent, one of the issues of wildfire suppression is estimating how much water is required to extinguish a certain section of the fire. In order to use easily distinguished and available indicators, the flame length and the area of the active combustion zone were chosen as suitable for the modelling of extinguishing requirements. Using Byram's and Thomas' equations, the heat release rate per unit length of fire front was calculated for low-intensity surface fires, fires with higher wind conditions, fires in steep terrain and high-intensity crown fires. Based on the heat release rate per unit length of fire front, the critical water flow rate was calculated for the various cases. Further, the required amount of water for a specific active combustion zone area was calculated for various fuel models. Finally, the results for low-intensity surface fires were validated against fire experiments. The calculated volumes of water can be used both during the preparatory planning for incidents as well as during firefighting operations.

The effects of transient heat release rate and crosswind on flame length and tilt angle of flames at different positions in the spread of fire over a diesel pool

2018 ◽  
Vol 43 (2) ◽  
pp. 189-199
Author(s):  
Liang Wang ◽  
Yuhong Dong ◽  
Shichuan Su ◽  
Chengyin Wei ◽  
Haibin Cui ◽  
...  
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Tilt Angle ◽  
Flame Length

Analysis of a diesel engine fueled with ternary fuel blends and alumina nano-additives at various combustion chamber geometries

2020 ◽  
pp. 1-12 ◽  
Author(s):  
George Antony Casmir Jayaseelan ◽  
Anderson Arul Gnana Dhas ◽  
Harish Venu ◽  
Jayaprabakar Jayaraman ◽  
Prabhu Appavu
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Heat Release Rate ◽  
Release Rate ◽  
Combustion Zone ◽  
High Performance ◽  
Specific Energy Consumption ◽  
Fuel Mixture ◽  
Nano Additives ◽  
The Impact

The present study investigates the impact of various combustion chamber geometries in a direct injection engine fueled with diesel–biodiesel–ethanol blends mixed with alumina nano-additives, named as high-performance fuel (HPF). The HPF was subjected to various combustion bowl geometries including standard hemispherical chamber geometry (SG), shallow depth reentrant bowl geometry (CG1), toroidal reentrant chamber geometry (CG2), and toroidal chamber geometry (CG3). Performance results reveal that in comparison with the SG-HPF arrangement, brake thermal efficiency increased by 11.51% and brake-specific energy consumption decreased by 10.37% when using the CG2-HPF arrangement. For emmisions, CG2-HPF reduced carbon monoxide, hydrocarbon, and smoke emissions by 33.53%, 18.35%, and 14.37%, respectively, in comparison with SG-HPF. Regarding combustion, CG2-HPF resulted in a high heat release rate owing to the reentrant chamber profile of CG2 which improves the air–fuel mixture rate, atomization, and evaporation rate, resulting in more efficient combustion, increased cylinder pressure, and increased heat release rate. Thanks to the geometry of the reentrant profile, the turbulent kinetic energy of the fuel mixture is maintained and returned to the combustion zone. Thus, the stagnation of rich mixtures within the combustion zone tend to decrease. Overall, the CG2 geometry was found to be the optimum geometry profile for HPF, based on improved performance and combustion characteristics, as well as reduced exhaust emissions.

Scale Modeling on the Effect of Air Velocity on Heat Release Rate in Tunnel Fire

2008 ◽  
Vol 18 (2) ◽  
pp. 111-124 ◽  
Author(s):  
C. Chen ◽  
L. Qu ◽  
Y. X. Yang ◽  
G. Q. Kang ◽  
W. K. Chow
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Air Velocity ◽  
Tunnel Fire ◽  
Scale Modeling

scholarly journals Effects of Discharge Area and Atomizing Gas Type in Full Cone Twin-Fluid Atomizer on Extinguishing Performance of Heptane Pool Fire under Two Heat Release Rate Conditions in an Enclosed Chamber

2021 ◽  
Vol 11 (7) ◽  
pp. 3247
Author(s):  
Dong Hwan Kim ◽  
Chi Young Lee ◽  
Chang Bo Oh
Keyword(s):  
Heat Release ◽  
Flow Rate ◽  
Heat Release Rate ◽  
Release Rate ◽  
Water Mist ◽  
Pool Fire ◽  
Sauter Mean Diameter ◽  
Discharge Area ◽  
Fire Extinguishing ◽  
Enclosed Chamber

In this study, the effects of discharge area and atomizing gas type in a twin-fluid atomizer on heptane pool fire-extinguishing performance were investigated under the heat release rate conditions of 1.17 and 5.23 kW in an enclosed chamber. Large and small full cone twin-fluid atomizers were prepared. Nitrogen and air were used as atomizing gases. With respect to the droplet size of water mist, as the water and air flow rates decreased and increased, respectively, the Sauter mean diameter (SMD) of the water mist decreased. The SMD of large and small atomizers were in the range of approximately 12–60 and 12–49 μm, respectively. With respect to the discharge area effect, the small atomizer exhibited a shorter extinguishing time, lower peak surface temperature, and higher minimum oxygen concentration than the large atomizer. Furthermore, it was observed that the effect of the discharge area on fire-extinguishing performance is dominant under certain flow rate conditions. With respect to the atomizing gas type effect, nitrogen and air appeared to exhibit nearly similar extinguishing times, peak surface temperatures, and minimum oxygen concentrations under most flow rate conditions. Based on the present and previous studies, it was revealed that the effect of atomizing gas type on fire-extinguishing performance is dependent on the relative positions of the discharged flow and fire source.

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