A experimental study on an extended flame and its behavior issued from an opening was conducted using a model compartment. A rectangular diffusion burner was adopted as a model fire source, and was set at the end wall in the compartment. The three different flow rate of propane gas of 30, 40 and 60 1/min were employed. We changed the opening area as full opening and 1/3 opening. The effects of pent-roof and fascia on the length of extended flame were also tested. The temperatures along the vertical wall during a fully developed fire were visualized using an infrared image processor and were also measured by means of thermocouples. The temperature contour maps were made based on both temperature data, and their crose correlation was elucidated.

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The hot gas spurting from a window of a burning concrete house has a tendency to flow from horizontally to vertically because of its buoyancy due to higher temperature than that of surroundings. The position of central axis of jet gives considerable influence upon the temperature of rising hot current ; when the hot air current rises apart from a wall above a window, it diffuses more widely than the current rising closely to the wall. In the former case, therefore, the temperature of the current is lower than that in the latter.
The position of a rising hot gas in various window shapes is discussed in this paper.
Results are as follows :
1. When the space above a window is free.
Using the velocity at a window as an initial condition, the equation of trajectory of the spurting gas can be obtained from the equation (1) and (6), where the upward acceleration due to the buoyancy is given.
Assuming that the rising air current is spurting from a line source placed at x_o inside a window plane, the trajectory shows a cubic parabola expressed in the equation (10) ; the parabola depends upon the window height, but has little connection with the air temperature in a burning room.
The parameter x_o was obtained from model experiments.
The above results were confirmed in model and full-scale experiments.
2. When a wall is above a window.
In this case the rising air current comes nearer to the wall than in the former case 1, depending upon the ratio of window width to window height ; when the window width is greater than the window height, the spurting air current comes nearer to the wall, and its temperature is higher, even if the spurting heat quantity per unit time is equal.

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In the previous report, we investigated the temperature and velocity fields of hot-layer along the ceiling in the full-scale and model tunnels.
The purpose of the present study is to clarify the relation between these experimental results and related parameters such as physical size of tunnel, burning rate of fire source, and Froude and/or Stanton numbers. An analytical approach to the evaluations of the attenuation coefficients of velocity and excess temperature with distance along the tunnel is made using a two-dimensional steady-state model consisting of a fire plume, an impinging over the assumptions employed, the estimated results are shown to be in reasonable agreement with the experimental data.

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本論文では, オープン・スペース, 高層耐火建物, 緑地帯の一体的整備による都市の耐火化を目指す防災緑地網整備計画を支援するために, 著者らの既開発の火災延焼シミュレーション・システムに, 新たに緑地メッシュを導入し, 拡張化することを試みている. そのために, 樹木の防火実験と, 火災の形状モデルを整理し, 緑地メッシュの状態推移判定アルゴリズムを提案している. また, 金沢市の実データを用いたシミュレーション実験により, 本拡張システムの諸動作確認をするとともに, 今後の課題を明らかにしている.

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Tokyo Metropolitan Fire Board made an experiment on the effect of the water spray method for the extinction of fire. We, research members of Building Research Institute, made use of this experiment, and measured the velocity and temperature of the fire flame when it was passing through the window of the burning house and its temperature after it passed the window. The important results obtained are as follows :
(1) In the window plane, the pressure difference between the inner and outer air increases linearly with the vertical distance from the neutral layer above which the inner pressure is larger than the outer, and so the stream velocity through the window increases quadratically with the height in the range above the neutral layer.
(2) The velocity distribution of that stream in the window plane is nearly similar to its temperature distribution.
(3) Above-mentioned similarity holds also between the velocity and temperature variation at any point in the window.
(4) The temperature decrease of the issued flame towards the down stream is just like that of the upward stream from the heat sources arranged on a circle or a circular heat source, already reported by S. Yokoi. The decrease is slight in a range near the window but it becomes remarkable from a certain distance and in this region the temperature is nearly inversely proportional to 5/3 power of the distance from the window.

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Checks on factors in characterizing fire-hazard of several organic building materials with respect to the criterion on ignition and surface flame-spread have been pursued by radiation-predominant present JIS A 1321-type furnace and convection-predominant vertical furnace (used to be JIS A 1321-type furnace) and Madison tunnel-type furnace. Following measurement have been conducted particularly for plywoods in ISO-type furnace ;
1) relative rate of heat-produced or dQ/dt.
2) decomposition-rate or dW/dt. (dL/dt in tunnel-furnace)
3) smoke produced and its production-rate or dC_A/dt.
4) temperature-disribution inside of the samples or T vs. thickness d.
5) radiation-intensity and temperature distribution on the surface of the samples in the respective furnaces.
Counter-charts representing the relations among those factors have been obtained and illustrated in the report for the further analysis on fire-hazard of the samples, which suggest the predominant effect of radiation from the fire-source in the furnace super-imposed on the convectional heat-transfer with respect to criterions on the ignition and combustion patterns of the samples. Secondly, distinctive difference concerning item 4 (based on the difference of the amount of heat-flux through the surface) have been recognized with the nearly same surface temperature between ISO-type furnace (presently available) and used to be JIS A 1321-type.
Thirdly linear relation has been observed between weight-loss of the samples or (W₀−W )/W₀ and sample-thickness d for a series of plywoods and coincidence has been recognized at d of ca. 12mm concerning the pattern on dQ/dW of test-samples vs. thickness d between present JIS A 1321-type and the convection predominant furnaces, which illustrated opposite patterns particularly for thin samples. Finally, similar patterns have been observed in dC_A/dt vs. dQ/dW and dC_S/dt vs. dQ/dW diagrams between present JIS A 1321-type furnace and Madison-type tunnel furnace (ASTM D E 286-69) for the surface flame-spread. We have reached to the following pattern concerning the fire-hazard of the organic building materials based on the above data ; dW/dt or dL/dt of the samples in the vertical and tunnel samples which are proportional to dQ/dt, will be dependent on the radiation-intensities through the surface of the samples.
Therefore, the appropriate setting of the measure of the radiation amount in the test-furnace corresponding to those as estimated by the respective phase in the modeling of fire will be the first preference in the criterion on the classification in the firehazard of organic interior building materials.

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  Molten marks on electric plugs or wall sockets found in fire sites often are great help, when we investigate the cause of the fires. It is known that the distance between each second arm of crystals called DAS (Dendrite Arm Spacing), that we see on the cross section of those molten marks, change depending on the atmospheric temperature at the time of a short circuit. Also it is already known that DAS between primary and secondary marks are clearly different. We created reference data to make use of DAS for practical investigation. In this study, we showed the relation between atmospheric temperature and DAS by making samples of molten marks at various temperatures. And we examined if this method was able to help assume the surrounding temperature at the time when the molten mark was produced. As a result, we found that the method has some possibility.
  We developed a new method for assuming the atmospheric temperature at the time of the short circuit using the reference data.

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It is said that some evacuation places in urban areas are threatened by fire spreading. In this paper, first four systems (1, 2, 3, and 4) are drawn up as alternatives of the risk assessment system based on several fundamental models. Then, a verification test of them is done using two experimental criteria, and System 2 and 4 are selected as promising ones. Next, comparative simulation analyses are done and the following is shown:
i) System 2 places a greater estimate on risk than does System 4.
ii) System 2 is sensitive to “velocity of wind”, while System 4 is sensitive to “size of fire”.
Finally, application studies are carried out and the zone of about 50 or 70m from flare is assessed to be at danger in the case by either system.

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(1) To make resistance tubes of extremely low voltage coefficient K_υ and of satisfactory characteristics the authors found the parallel filament type most suitable, where K_υ is a coefficient in the formula V=K_υI^1.85.
And also it was found that series type is most suitable to make tubes having extremely high K_υ.
(2) To design resistance tubes of K_υ of desired value, the relation between K_υ and filament size w (M. G.) and filament length l was investigated. In consequence the next formula was obtained.
K_υ=22.3(l-5)w^-1.676

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Characterization on smoke evolution of organic building materials in fire have been pursued with respect to the change in dissymmetry factor Z in light scatterring data.
The change in dissymmetry factor Z has been recognized to be very sensitive to the change in radius of smoke particle by the secondary oxidation in hot environment and above change in Z induced by the change in radius of smoke particle have been also recognized to be influenced by the change in particle size distribution.
Theoretical consideration on the data concerning the change in Z factor, electro-microscopic observation and Royco Particle Counter analysis of smoke particle evolution under respective oxygen partial pressure will suggest that the change in turbidity dC_s/dt in the previous report (Part I) will be mainly due to the change in particle number dN/dt which will depend on thermal decomposition rate dW/d_t of organic materials at high temperature.

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The aim of this investigation is to give a description of the flow behaviors of a stratified layer beneath the ceiling associated with tunnel fires.
This paper deals with the experimental results on the hot-layer movement in the full-scale and model tunnels which were closed at one end and completely open at the other. The fire sources in these tests were an alcohol pan on the floor near the closed end. The heat output was maintained for a period of about 8 min., during which time approximately constant heat-release rate conditions prevailed. Temperature and velocity distributions were measured at several locations of the tunnel during the steady burning period of the fire. The influence of forced ventilation on the hot-layer was also studied in the full-scale.
Following results were obtained;
(1) Hot-layer depth defined as the observed flow thickness was retained to be equal to the open end.
(2) Temperature and steady travelling velocity of the hot-layer decreased exponentially with distance from fire source respectively.
(3) The vertical temperature and velocity profiles showed a remarkable simularity between the full-scale and model experiments respectively.

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Three types of ignition in wood, Ignition, Flashing and Carbon-ignition, are classificated experimentally by difference of time lag. By this results, the following facts are made clear : —
(1) Three types of ignition are recognized at low temperature (<600°C).
(2) Three types are not separated at high temperature.
(3) Carbon-ignition break out more easily than flashing and ignition.
(4) Carbon-ignition is not obtained when air flow on the surface of wood is ceased.
(5) The theory given at the last report is applicable in flashing phenomenon.
Moreover, activation energy of thermal decomposition 36.9 kcal is determined from the theory in the last report and the results of experiment in this report.

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A piece of filter paper was rolled several turns to form a circular rod of 3.8 mm radius. When this rod was kept vertically and was kindled at its top, a flame proceeded downward.
Heat is transferred to an unburnt part by both the conduction through paper rod and the radiation from the flame. When the heat quantity given to the part comes up to a certain value, combustion reaction begins in this part resulting in the flame propagation to this layer. The study reported in this paper is concerned with the ratio of heat quantities transferred in both ways.
In order to observe heat radiation from the flame, we used a small square (2 mm × 2 mm) aluminum foil (thickness = 0.075 mm), on a surface of which the junction of a thermocouple of copper-constantan (dia = 0.12 mm) was stuck to form a radiometer of small size. Both surfaces of the foil were blacked out to make the radiometer more sensitive to the incident radiation. Its sensitivity was calibrated by a conventional thermopile-type standard radiometer.
The intensity of radiation on the radiometer, placed as close to the rod-surface as possible, was observed when the flame front attained to a point adjacent to the radiometer. From these reults, the incident radiation per unit time on the side of the disk, supposed in the rod just under the flame front, was calculated. On the other hand, heat gains by conduction per unit time of this disk was calculated from the temperature distribution in the rod and the conductivity of the filter paper.
Comparing both values, it has been found that the ratio of radiation intensity to the conductive heat gains is as small as 6.2/180. In setting up a theory of flame propagation along a vertical rod, therefore, one can ignore the effect of heat radiation, as a first approximation, compared with the heat conducted through the rod.

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The temperature distribution in the upward stream from the circular horizontal heat source is investigated. The behaviour of the stream is nearly similar to that of the stream from the heat sources arranged in the circle.
The similarity theory of the upward stream is discussed in this paper, and the application of this theory to the real house-fire is expected.

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Study on fire situation in Consideration of the Wind Flow in a Built-up Area

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In this paper, we have dealt with the fire spread speed at the time of the earthquake. We analyzed the data from the Great Hanshin-Awaji Earthquake. It has been expressed with the factor such as the district of urban area to be burnt, the complete collapse rate, the wind velocity and also time. From the burn-out area and the fire front length, the mean value of fire spread speed have been obtained. Furthermore the Dredictions of fire spread speed that are the mean value, the maximum value, and so forth have been examined. And we showed that we are able to predict the fire spread speed at the time of earthquake by using our fire spread model.

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