• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.11
• /
• pp.1015-1025
• /
• 2010

In this present study, we experimentally investigated the effects of electric fields on the characteristics of flames spreading over electric-wires with AC fields. The dependence of the rate at which a flame spreads over polyethylene-insulated wires on the frequency and amplitude of the applied AC electric field was examined. The spreading of the flame can be categorized into linear spreading and non-linearly accelerated spreading of flame. This categorization is based on the axial distribution of the field strength of the applied electric field. The rate at which the flame spreads is highly dependent on the inclined direction of the wire fire. It could be possible to explain the spreading of the flame on the basis of thermal balance.

• Fire Science and Engineering
• /
• v.19 no.1 s.57
• /
• pp.51-58
• /
• 2005

In this paper, The experimental materials of painted fire resistant paint on substrate, FRP, PVC, AL and stainless steel that fire resistant paint developed newly were evaluated as the hazard elements : the fire resistibility of the materials, fire spread test of flame, the oxygen index, flammability, the smoke density. the toxicity index from it when it burned. As a result of the experiments, the AL and the stainless steel were passed of fire resistant class 1, the FRP, the AL, and the stainless steel were ignited of fire spread test of flame, all the experimental materials showed about $50\%$ of oxygen index, V-0 of flammability, and 43-338 of maximum smoke density at flaming mode used smoke density chamber. Also, they showed that the toxicity index of combustion products were 0.57-1.12.

• Fire Science and Engineering
• /
• v.23 no.3
• /
• pp.67-72
• /
• 2009

This paper is for response feature of fire detectors not only to analysis response feature of fire detector, but also to observe flame spread of inside-building and fire enlargement by using the row house which is supposed to be broken up. Many kinds of popular detectors such as heat type detector(differential type, fixed temperature type, Analogue type)and smoke type(light scattered type, Analogue type, single alarm type) were installed in the house in order to check for the change of temperature by installing of thermocouples. As a result, smoke detectors are better than heat detectors when it comes to making effective fire-detect system in the row house.

• Fire Science and Engineering
• /
• v.31 no.5
• /
• pp.7-11
• /
• 2017

The purpose of this study is to recognize the necessity for the management of the available materials in cases of arsons and to prevent arson gaining an understanding of the combustion characteristics of the flammable materials and combustion accelerants in arson cases. We investigated and analyzed the statistical data on arsons and selected flammable materials (wood, paper, synthetic textiles, synthetic resins), and combustion accelerants (gasoline, diesel, solvent) that are frequently used in cases of arson. We conducted a thermogravimetric analysis to assess the thermal properties of the flammable materials. Also, we conducted burning and flame spread rate tests for the purpose of comparing and analyzing the combustion characteristics of the flammable materials and combustion accelerants.

• Fire Science and Engineering
• /
• v.26 no.3
• /
• pp.106-111
• /
• 2012

In this study, EIFS (Exterior insulation finish system) of exterior cladding was applied Cone calorimeter test to confirm the effect of flame retardant. As a results, the initial ignition points in accordance with the coated form and concentration of the flame retardant was delayed. But flame resistant treatment of EIFS cladding to control the fire will not affect confirmed that. In addition, EIFS that uses high-density and low-density due to difference in the density of the impact of the fire was no difference. The exterior of the ignition experiment occurred before and after 40 seconds, heat release rate to 100 seconds appears to occur about 90 % compared with the other exterior wall materials, the initial fire spread very fast was confirmed. EIFS cladding in order to prevent the spread of fire in the application of EIFS legally use is limited by the use of the building. And flame spread can be prevented, such as a vertical outer wall compartment measures are urgently needed.

• Journal of Advanced Marine Engineering and Technology
• /
• v.38 no.9
• /
• pp.1150-1155
• /
• 2014

To prevent the flame spread in FRP vessel in fire, the engine-room of the vessel should be constructed additionally with laminated fire-retardant resin over 3 times or equivalent insulation materials to former according to the relevant standard for FRP vessel structure. It is surveyed that insulation materials called 'Gel coat' are widely used in FRP fishing vessel, however, test method and its criteria for Gel coat are not clearly establish and have not been evaluated yet, while test method and criteria for fire-retardant resin and fire-retardant polyurethane composite are described in test standard for type-approval. In this study, 3 fire-retardant resins, 4 gel coats, 1 flame-retardant paint and 1 polyurethane composite were selected based on the survey and were evaluated according to both IMO FTP Code part 5 and flame-retardant test. When comparing based on CFE values from flame-spread test, average value for 4 gel coats were lower than that of 3 fire-retardant resins. As for flame-retardant test, there were no significant differences between fire-retardant resin and gel coat, based on charred area.

• Journal of Mechanical Science and Technology
• /
• v.16 no.11
• /
• pp.1485-1496
• /
• 2002

In order to investigate the fire-induced smoke movement in a three-dimensional room with an open door, numerical and experimental study was performed. The center, wall, and corner fire plumes for various sized fires were studied experimentally in a rectangular pool fire using methanol as a fuel. The numerical results from a self-developed SMEP (Smoke Movement Estimating Program) field model were compared with experimental results obtained in this and from literature. Comparisons of SMEP and experimental results have shown reasonable agreement. As the fire strength became larger for the center fires, the air mass flow rate in the door, average hot layer temperature, flame angle and mean flame height were observed to increase but the doorway-neutral-planeheight and the steady-state time were observed to decrease. Also as the wall effect became larger in room fires, the hot layer temperature, mean flame height, doorway-neutral-planeheight and steady-state time were observed to increase. In the egress point of view considering the smoke filling time and the early spread of plume in the room space, the results of the center fire appeared to be more dangerous as compared with the wall and the corner fire. Thus it is necessary to consider the wall effect as an important factor in designing efficient fire protection systems.

• Journal of ILASS-Korea
• /
• v.17 no.3
• /
• pp.128-133
• /
• 2012

The present study aims to examine the influence of flame spray distance on the thermal behavior of micro-metal particles and the morphological characteristics of $Ni_{20}Cr$ layers coated on the preheated SCM415 substrates by using the conventional flame spray system. Commercially available nickel-based $Ni_{20}Cr$ particles with a mean diameter of $45{\mu}m$ were used. In addition, CFD simulations using a commercial code (FLUENT ver. 6.3.26) were conducted to estimate temperature and velocity distributions of the continuous and discrete phases before impact on the substrate. From FE-SEM images of coated layers on the substrates, it was observed that as the spray distance decreased, the metal particle morphology showed splash-like patterns and such a short stretch shape, resulting from higher particle momentums and the impact of partially melted particles. Moreover, it was found that the spray distance should be considered as one of important parameters in controlling the porosity and the adhesion strength.

• Fire Science and Engineering
• /
• v.32 no.5
• /
• pp.15-21
• /
• 2018

This study examined the growth characteristics and carbonization pattern when a fire occurs due to a flammable liquid sprinkled on a vinyl floor. When acetone was sprinkled on a floor, the flame reached its peak in approximately 0.2 s after it was ignited. The lower part of the flame showed a laminar pattern while the upper part showed a turbulent pattern. The pattern showed a turbulent pattern and generated white smoke. The combustion completed floor surface showed carbonization of a dim pore pattern. In the case of benzene, an intense flame was formed in approximately 0.6 s after ignition. The flame length was measured to be approximately 50 mm. When the flame became weak, a significant amount of black smoke was generated due to incomplete combustion. The combustion completed floor surface showed carbonization of a pour pattern and splash pattern. In the case of alcohol, an intense flame was formed in approximately 1.1 s after ignition. In addition, the depth of carbonization was significant where the flammable liquid was collected and a trace of carbonization was observed at the boundary of the flow path of the flammable liquid.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.29 no.10 s.241
• /
• pp.1148-1155
• /
• 2005

In this study, the influence of changing combustor pressure on nitric oxide emission was investigated. Expansion of reaction region was more clear in the P$^{*}$ <1 conditions compared to the P$^{*}\geq1$ conditions, and it could be observed that flames are distinct in the P$^{*}\geq1$ conditions and that brightness is relative low and wide distribution is shown in the P$^{*}$ <1 conditions. In the respect of temperature distribution, narrow and high-temperature region was shown in the P$^{*}\geq1$ conditions. On the other hands, overall uniform temperature distributions were shown in the P$^{*}$ <1 conditions. Nitric oxide emission decreased with decreasing combustor pressure. This tendency was explained by the mean flame temperature distribution. Low NOx combustion is ascribed to wide-spread reaction region in the low combustor Pressure and oscillation were shown P$^{*}\leq0.97$, and strength and sizes of oscillation were more increased with lower pressure index. These results demonstrate that flame shape and nitric oxide emission can be controlled with changing combustor pressure.