Bulletin of Japan Association for Fire Science and Engineering
Online ISSN : 1883-5600
Print ISSN : 0546-0794
ISSN-L : 0546-0794
Volume 5, Issue 2
Displaying 1-7 of 7 articles from this issue
Paper
  • Takashi SEKINE
    1956 Volume 5 Issue 2 Pages 33-38
    Published: 1956
    Released on J-STAGE: February 25, 2015
    JOURNAL FREE ACCESS
    The vertical distribution of mean wind velocity and fluctuation was observed at several places in Tôkyô, using Robinson small cup anemometers, Nakaasa type wind vane and other vane which rotates around the horizontal axis. We observed the fluctuation in the velocity and the angle of inclination of the vane at every 5 seconds.
    The results are as follows : 1. Vertical distribution of mean velocity fits to the logarithmic law,
    u = (u/k) ln ((Z-d) / Z0).
    where u, u, Z0, d and k denote the velocity at height Z, the friction velocity, the roughness parameter, the zero plane displacement and Kármán’s constant, respectively.
    2. Frequency distribution of turbulence components is approximately normal Gaussian distribution except vertical component.
    3. Correlation between the wind velocity and the angle of inclination of the vane in the vertical direction is small.
    4. When the vane directs downward its continuing time is long and the wind velocity is large. But when the vane directs upward the continuing time is shorter and the velocity is smaller.
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  • Jun MIYAMA, Toshihisa USUBA, Kaoru KITA
    1956 Volume 5 Issue 2 Pages 39-42
    Published: 1956
    Released on J-STAGE: February 25, 2015
    JOURNAL FREE ACCESS
    (1) To make resistance tubes of extremely low voltage coefficient Kυ and of satisfactory characteristics the authors found the parallel filament type most suitable, where Kυ is a coefficient in the formula V=KυI1.85.
    And also it was found that series type is most suitable to make tubes having extremely high Kυ.
    (2) To design resistance tubes of Kυ of desired value, the relation between Kυ and filament size w (M. G.) and filament length l was investigated. In consequence the next formula was obtained.
    Kυ=22.3(l-5)w-1.676
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  • Kazuo AKITA
    1956 Volume 5 Issue 2 Pages 43-48
    Published: 1956
    Released on J-STAGE: February 25, 2015
    JOURNAL FREE ACCESS
    The fact that heat is generated in process of thermal decomposition of wood, is known, but the mechanism and calorimetrical data of this phenomena are not clear at present.
    In this paper, mechanism of this heat generation under the air lean condition is examined experimentally and theoretically. By that results, it is considered that the heat is generated with secondary catalytic decomposition and polymerization of primary decomposition products, and in this case calorific value is about 30 cal. per gram of wood, which determined by numerical calculation of heat conduction in wood. On the contrary, mechanism of heat generation under the air rich condition is understood easily as the oxidation of product gases and product carbons.
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  • Keizaburo OKAJIMA, Yorio YAZI
    1956 Volume 5 Issue 2 Pages 49-52
    Published: 1956
    Released on J-STAGE: February 25, 2015
    JOURNAL FREE ACCESS
    We observed in a room the shape of flame of alcohol burning in circular dishes (dia. 10~75cm).
    The shape of a flame varies periodically. The period is short when the dish diameter is small, but increases gradually and tends asymptotically to a constant value as the diameter of dish becomes larger.
    The burning velocity also increases with the dish diameter and tends to a certain constant.
    The flame height is proportional to the diameter of the dish, and is about 1.6 times of the latter.
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  • Shizuo YOKOI
    1956 Volume 5 Issue 2 Pages 53-58
    Published: 1956
    Released on J-STAGE: February 25, 2015
    JOURNAL FREE ACCESS
    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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  • Kunio KAWAGOE, Yoshio MIWATARI, Hiroshi IMAZU
    1956 Volume 5 Issue 2 Pages 59-61
    Published: 1956
    Released on J-STAGE: February 25, 2015
    JOURNAL FREE ACCESS
    The purpose of this investigation was to determine the fire retardant performance of 4 type fire safety steel cabinets protected with the gypsum plaster and to develop the fire safety classification for the assembly.
    Fire endurance tests were conducted in accordance with the standard specifications for fire tests of building construction (JIS A 1302).
    Temperatures inside cabinets are considerably below the allowable critical temperature.
    Safety, determined by the fire endurance tests, are correspond to JIS A 1302 Class III.
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  • Kojiro KAMEI
    1956 Volume 5 Issue 2 Pages 62-66
    Published: 1956
    Released on J-STAGE: February 25, 2015
    JOURNAL FREE ACCESS
    The term of “Conflagration” used in this study shall exclude the fire which were broken out by air-raid in the world War II and earthquake.
    Strong wind with no rain has much reciprocity to conflagration, but there were no actual data for distribution of directions of wind in the regions of Japan.
    As a result of this study the author have found the following interesting facts ;
    1) I & II regions (Hokkaido district) has chance of conflagration when SSW-W strong wind blow.
    2) III region (Nippon Sea side) has chance when SE-SW strong wind blow.
    3) IV region (Pacific Ocean side) has chance when W-NW strong wind blow.
    4) V region (Seto Inland Sea side) has chance when E-W strong wind blow and.
    5) VI region (Nankkai district) has chance when W-NW strong wind blow.
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