JOURNAL OF THE MARINE ENGINEERING SOCIETY IN JAPAN
Online ISSN : 1884-4758
Print ISSN : 0388-3051
ISSN-L : 0388-3051
Volume 16 , Issue 10
Showing 1-8 articles out of 8 articles from the selected issue
  • [in Japanese]
    1981 Volume 16 Issue 10 Pages 839-846
    Published: 1981
    Released: May 31, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese]
    1981 Volume 16 Issue 10 Pages 847-852
    Published: 1981
    Released: May 31, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese]
    1981 Volume 16 Issue 10 Pages 853
    Published: 1981
    Released: May 31, 2010
    JOURNALS FREE ACCESS
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  • Osami Nishida, Seiya Mukohara
    1981 Volume 16 Issue 10 Pages 854-864
    Published: 1981
    Released: May 31, 2010
    JOURNALS FREE ACCESS
    For determining the soot particle size and concentration in flames, the scattered light intensities at various angles has been calculated as a function of particle diameter and complex index of refraction by the Mie's theory. In a preliminary experiment, a water suspensoid of polystyrene latex particles having a diameter of 91 nm and 176 nm were examined and good agreement between experiment and theory were found.
    In this paper, profiles of local soot particle size (Ds: nm), number density (Ns: particles/cm3 ) and volume fraction (Ns : cm3/cm3) together with temperature are measured in propane/air laminar diffusion flames. A special burner and laser scattering technique are used for this purpose.
    At the axial distance, the diameters of soot particles lie within the limits of 60 and 200 nm. The number density and volume fraction of soot particles are obtained in the range from 107 to 1011 particles/cm3 and from 10-8 to 10-5 cm3/cm3 respectively.
    The largest particles are observed in the neighbourhood of nozzle, and then decreases toward the middle of the flame, however, the soot particle density increases strikingly. Large agglomerates of soot are seen to escape the tip of the flame.
    At the radial distance, a considerably larger particles of soot are found near the flame front as compared with the central pyrolysis zone. It is suggested that the soot particle formation in the diffusion flame is confined to the high-temperature region on the fuel-rich side of the reaction zone.
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  • Mitsuhiro Kinugawa, Takeshi Takao, Masashi Nagai
    1981 Volume 16 Issue 10 Pages 865-872
    Published: 1981
    Released: May 31, 2010
    JOURNALS FREE ACCESS
    The combustion chamber walls of a slow speed diesel engine are damaged mostly on the cooled surfaces. This kind of damage is considered to be caused by the superimposed stress wave fatigue through combined effects of the thermal stresses and the gas pressure stresses and by the corrosion fatigue in the hot water.
    The fatigue strength under corrosive environment of hot water is the important problem when the inhibitor added in the hot water has not so good effects over the environments.
    So the superimposed stress wave fatigue tests in the 90°C water were carried out by using the Cr-Mo cast steel, and the method for fatigue life estimation under these conditions was discussed.
    Through the investigations the following were clarified.
    (1) The effect of mean stress on the fatigue strength in the 90°C water is smaller than that in the air.
    (2) There exists a linear corelation between the superimposed stress wave fatigue life (Nf1) and the number of cycle of superimposed stress wave (n) on the double logarithm scale. And (Nf1) decreases with the increasing of (n) .
    (3) The superimposed stress wave fatigue strength in the 90°C water can be estimated by using Yamada's evaluation equation of the mean stress and the modified Miner's rule.
    (4) Stress-strain relationships on the notch roots of the notched specimens can be derived from Neuber's equation.
    (5) The fatigue lives of the actual failed cylinder covers have good agreements with the estimated lives by using the above estimation method.
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  • Takeshi Hashimoto, Hitoshi Kaneko, Masahiro Sada, Kazusada Ikeda
    1981 Volume 16 Issue 10 Pages 873-882
    Published: 1981
    Released: May 31, 2010
    JOURNALS FREE ACCESS
    This paper describes the Totalization and Systematization of the following analyses on the marine engine field data (1400 samples) . They are Principal Component (PCA), Normal Probability Scale (NPS), Fundermental Original Statistiscs (FUNDOS) for Specialized Pattern Cluster Analysis (PPCLUST) .
    Having only an objective variable of Man-Hour per occurrence mhi, the five vector spaces of factor scores U with all the scores of the input variables Xi by PCA are represented by the several groups of factor score Uj which is corresponding to Zj; U1 by the group of input variables (X24, X34, X35) of hardware of ship and engine, U2 by (X1, X2, X3) of man-hour informations, U3 by (X6, X21, X32, X33) of software of engine plants system, U4 by (X4, X5, X7, X8) of major maintenance and U5 by (X18, X22, X25, X28) of hardware of engine plant system.
    An additional program FUNDOS is useful for beginner of this systematic program package due to the feasible fundermental statistics of original data.
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  • Minoru Nakashima
    1981 Volume 16 Issue 10 Pages 883-892
    Published: 1981
    Released: May 31, 2010
    JOURNALS FREE ACCESS
    The development of Sleeve Mounted Propeller have been proceeded to improve on fitting method of conventional propeller. This improved system, propeller secured on shaft with sleeve, has characteristics as follows;
    (1) Based facing up of propeller as the propeller can be faced up with the sleeve instead of the propeller shaft.
    (2) Simplified machining of the propeller shaft so as to get along without the tapered and screwed end.
    To prove the reliability, a model propeller was prepared and tested. As a result, the system was confirmed to be reliable and a great number of information for the design was obtained.
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  • Wasaburo Murai, Hideki Takagi, Shozo Kaneko
    1981 Volume 16 Issue 10 Pages 893-901
    Published: 1981
    Released: May 31, 2010
    JOURNALS FREE ACCESS
    As a consequence of growing trend in size of an electric distribution system at vessels, the ground fault will become unable to disregard since one-line fault current becomes higher, and necessity of introducing some supervisory or protective method against the fault, which is higher graded than ever, will be increasing. This time, we had an opportunity to research the ground fault phenomena at vessels. We report the results here, in which we have established the theoretical formula for the fault and carried out the numerical calculations at 440V AC 60Hz system, then confirmed those values on a vessel field. This study was also established on the basis of some aforegoing papers on the similar titles but further provides some practical method for calculating one-line fault current by utilizing materials of installation records of distribution system of a vessel, which will be applicable generally to vessels of any kind. In order to realize it, electrostatic capacitance against an earth or a hull on cables and various electrical machines were regulated for each size. Then the total capacitance of the experimental ship was calculated in the identical charging condition of circuitry at test and compared with that measured. A result was obtained that those two values were within a small tolerance.
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