• Fire Science and Engineering
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• v.31 no.4
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• pp.103-110
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• 2017

With the common tendency in the accordance with the trend, low-stories built edifices that are Pilotis-oriented structured exponentially and constantly increasing its number of buildings. It inevitably contains its risks of facing conflagrations as most of its part is used as parking lots. In the parking lots, the length of the flame has a heavy-weighted possibility that it would get increased because the heat release rate gets relatively high due to the vehicle insulation. Following on top of that, due to the nature of the Pilotisconsisting of pillars, there is a risk of flame spread to the adjacent building if the same Pilotis-structured buildings are adjacent to each other, if the flame spreads to the surroundings due to the influence of the wind. Because the most of the pilotis-structured-buildings have this entrance that makes the residents be able to enter, if the entrance were plugged the resident get a serious risk of a poisonous gas and a flame. Therefore, if the parking-lots of the pilotis-structured-buildings are adjacent to each other it requires a space to prevent the place from the spread of flame. This research studied how far is appropriate to prevent flame spreading with FDS. As a result, the study found that the distance at least 3.0 m is required.

• Fire Science and Engineering
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• v.32 no.3
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• pp.42-50
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• 2018

The effect of sub-grid turbulence and combustion models on the mean flame height in a heptane pool fire according to the Fire Dynamics Simulator (FDS) version (5 and 6) based on Large Eddy Simulation (LES) was examined. The heat release rate for the fire simulation was provided through experiments performed under identical conditions and the predictive performance of the mean flame height according to FDS version was evaluated by a comparison with the existing correlation. As a result, the Smagorinsky and Deardorff turbulence models applied to FDS 5 and 6, respectively, had no significant effects on the mean flow field, flame shape and flame height. On the other hand, the difference in pool fire characteristics including the mean flame height was due mainly to the difference in the mixture fraction and Eddy Dissipation Concept (EDC) combustion models applied to FDS 5 and 6, respectively. Finally, compared to FDS 6, FDS 5 provided the predictive result of a significantly longer flame height and more consistent mean flame height than the existing correlation.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.634-643
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• 2023

Purpose: Underground common duct fires are steadily occurring, and the proportion of property damage is particularly large among property and human casualties caused by fires. Especially, cable fires that occur in common areas can spread vertically quickly and pose a great risk. This paper aims to scientifically analyze the nature of the fire by reproducing the fire through experiments. Method: To analyze the characteristics of cable fires in underground common duct, heat release rate and temperature changes were measured through Room-corner (ISO 9705) test, and the vertical and horizontal propagation of cable fires was quantitatively compared and analyzed. Result: The Room Corner Test (ISO 9705) was used to compare the temperature changes at each data logger point. The results showed that the time it took for the fire to reach the ignition temperature in the horizontal and vertical directions from the center point of the first-tier cable was 589 seconds and 536 seconds, respectively, which means that the vertical fire propagation is 53 seconds faster than the horizontal propagation. This proves that the vertical propagation of fire is relatively faster than the horizontal propagation. The horizontal propagation speed of the fire was also compared for each floor cable tray. The results showed that the third-tier cable propagated at 3.4 times the speed of the second-tier cable, and the second-tier cable propagated at 1.5 times the speed of the first-tier cable. This means that the higher the cable is located, the faster the fire spreads and the larger the fire becomes. Conclusion: This study identified the risks of cable fires and analyzed the risks of vertical fire propagation during cable fires based on the results of the Room Corner Test. Studies to prevent the spread of fire and fire response policies to prevent vertical fire propagation are required. The results of this study are expected to be used to assess the fire risk of common areas and other fires.