Transactions of the Japan Society of Mechanical Engineers
Online ISSN : 2185-9485
Print ISSN : 0029-0270
ISSN-L : 0029-0270
Volume 30, Issue 216
Displaying 1-9 of 9 articles from this issue
  • Mikio HISHIDA
    1964 Volume 30 Issue 216 Pages 941-947
    Published: August 25, 1964
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    Boundary layer in the entrance region of a circular pipe is calculated using the Karman-Pohlhausen method. Velocity distribution in the boundary layer is approximated by a quartic. The coefficients of the quartic are the function of the K, which is a function of the acceleration of the core flow. The momentum equation is integrated approximately, and the results are represented by the polynomials. The results are compared with the values which are calculated by other's theoretical solutions, and also with those from the Nikuradse's experiment.
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  • Goro KAMIMOTO, Shozo FUJIWARA, Takashi SHIMIZU, Hiroshi OKAMURA
    1964 Volume 30 Issue 216 Pages 948-954
    Published: August 25, 1964
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    This paper deals with the two-dimensional potential flow around the guide vanes of water turbine. This method is based on the singularity-method, replacing the guide vanes with the vortices, sources and sinks distributed along the mean camber lines of the vanes. The numerical calculation is not yet successful in the case of guide vanes composed of a large number of vanes and with the small ratio of inner-outer diameter. The calculation was performed by the digital computer. The results of calculations agree well with those of air tests on the guide vane of Kaplan Turbine.
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  • Toshio SHINOHARA
    1964 Volume 30 Issue 216 Pages 955-964
    Published: August 25, 1964
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    In this paper the mutual interference between succeeding turbine blade rows, one is typical stator and another is typical rotor has been experimentally investigated. Nozzles and buckets were tested in tandem on the two dimensional wind tunnel. Both cascades remainded stationary during the test. Relative position of the two cascades were varied both in tangential and axial directions. The difference angle between the nozzle exit and bucket inlet and the ratio of blade spacing of two rows were also varied. As a result the general characteristics of mutual interference of between adjacent blade rows in turbine were clarified.
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  • Ichiro WATANABE, Ichiro ARIGA, Kunio FUJIE
    1964 Volume 30 Issue 216 Pages 966-976
    Published: August 25, 1964
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    Results of some experimental investigations of flow in rotating impeller passages of a radial turbine are presented. Velocity and static pressure measurements were made with a yaw meter probe fitted within the impeller channel of the rotating impeller. The influences of two performance parameters, i.e. non-dimensional weight flow and non-dimensional rotation speed on the flow behavior within the impeller passage are shown. Further, the flow patterns in blade-to-blade planes are shown for three different passage depthes. In addition, a theoretical analysis for mixed flow type is made, which includes the inward-flow type as a special case. For the necessary boundary values at inlet of the impeller in the theoritical study, we use the values observed in the experiment. Theoretical results show a fairly good agreement with the experimental data.
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  • Yasuo MORI, Wataru NAKAYAMA
    1964 Volume 30 Issue 216 Pages 977-988
    Published: August 25, 1964
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    The effect of curvature on heat transfer for fully developed laminar flow in curved pipes on the condition of constant wall temperature gradient is studied theoretically and experimentally. For the case of large Dean numbers Re√(a/R), a boundary layer is considered to exist along the pipe wall. The momentum and energy integral equations of the boundary layer are solved to the second approximation, and theoretical formulae for resistance coefficient and Nusselt number are obtained for a range of large Dean numbers. In order to ascertain the theoretical result, velocity and temperature distributions are measured in air flow through the pipe of radius ratio R/a=40 and of an inside diameter of 35.6 mm. From this experiment it is assured that the boundary layer approximation may be applicable to our case. Nusselt numbers obtained by the experiment are in good agreement with the theoretical results.
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  • Kaneyasu NISHIKAWA, Hisao KUSUDA, Ken'ichi YAMASAKI
    1964 Volume 30 Issue 216 Pages 989-994
    Published: August 25, 1964
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    A number of theoretical and experimental studies on growth and collapse of bubbles have been made in order to clarify the boiling phenomena. Almost of those experiments, however, have been made with heating surface of smaller size than bubble diameter. Authors have been doubtful of the validity of applying such experimental results to boiling with larger heating surface. In order to clarify the dependence of the bubble growth and collapse upon the shape and size of heating surface, they carried out experiments by means of heating surfaces of horizontal circular brass plates 10 cm and 14 cm in diameter respectively and of horizontal small platinum wire 0.5 nm in diameter. From their experiments following facts were made clear. (1) Bubble growth and collapse are independent of heat flux. (2) Bubble collapse is strongly influenced by the degree of subcooling. (3) Bubble growth and collapse which essentially dominate boiling heat transfer are considerab1y affected by the size of heating surface. According to the above-mentioned facts, it may be concluded that one must be careful of applying the experimental results with a heating surface of a size smaller than bubble diameter to boiling with a larger heating surface.
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  • Susumu KOTAKE, Keizo HATTA
    1964 Volume 30 Issue 216 Pages 995-1001
    Published: August 25, 1964
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    The mechanism of the generation and characteristics of the noise associated with combustion are studied. It is shown that the dominant factors on the generation of the combustion noise are the velocity turbulences and the entropy turbulences, acting as equialent acoustic dipole and source respectively. Especially, concerning the diffusion flame of premixed gases, the noise in the laminar flame is mostly due to the entropy fluctuation (source-like characteristics) and that in the turbulent flame is mainly attributed to the velocity fluctuation (dipole-like characteristics). The noise intensities are proportional to U2 and U4 respectively and to the cubic power of the diameter of the nozzle.
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  • Teturo NAKADA
    1964 Volume 30 Issue 216 Pages 1002-1009
    Published: August 25, 1964
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    In the present paper, the reflective conditions of pressure wave in the exhaust pipe systems with diffusers, nozzles, bends or elbows, and in the exhaust manifolds were measured by the shock-tube method. This method was based on the characteristic relation of pressure wave and the shock-tube principle. Some results obtained were as follows : 1) As to nozzle, the experiments showed the coincidence with the theory for a weak shock wave, but as strength of its incident pressure increased, the discharge coefficients became larger. 2) Judging from the theory and the experimental results, the diffuser effect could not be improved for the area ratio above 4. 3) As to bends or elbows, the experimental results agreed well with the theoritical one. 4) The results were able to clearly explain the phenomena in the last experiments using uniflow two-cycle diesel engine.
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  • Yoshiro MASUDA
    1964 Volume 30 Issue 216 Pages 1011-1016
    Published: August 25, 1964
    Released on J-STAGE: March 28, 2008
    JOURNAL FREE ACCESS
    It is known that volumetric efficiency at a given speed under full open throttle varies with the induction system attached to the carburetor. Then constant diameter of different length was used as simple added induction system. The relationship between the engine speed showing maximum volumetric efficiency and the length of these pipes was analysed in order to find out the equivalent acoustic characteristics applicable to the induction system from the carburetor to the piston. The equivalent acoustic system of engine having the same characteristic as above could be found, which consists of one chamber with certain amount of volume, one pipe and one venturi located between the two. In order to obtain improved volumetric efficiency under normal engine speed range, some experimental added induction systems were designed by simulating the equivalent acoustic system of the engine on an electric circuit, and the test results conformed to the practicability of the above analysis.
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