Journal of Japan Society of Fluid Mechanics
Online ISSN : 2185-4912
Print ISSN : 0286-3154
ISSN-L : 0286-3154
Volume 8, Issue 4
Displaying 1-7 of 7 articles from this issue
  • Isamu YABE
    1989 Volume 8 Issue 4 Pages 289-300
    Published: December 30, 1989
    Released on J-STAGE: March 07, 2011
    JOURNAL FREE ACCESS
    The present paper gives a brief review based on the author's studies mainly on the problems of the fluid dynamics and dispersion around a single gas bubble. This review is divided into three parts : the first relates to the investigation on the dispersion phenomena of gas molecules dispersing into the liquid using a color reaction method ; the second relates to the measurement of the velocity distributions around a gas bubble by the tracer method, and examination on the appropriateness of conventional models by comparing with the actual empirical evidence ; the third relates to the measurement of streamlines, vorticity and stress distributions around a gas bubble by the tracer method as well as discussion on the mechanism about the generation of vortex and separation of streamline.
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  • Satoshi SAKAI
    1989 Volume 8 Issue 4 Pages 301-310
    Published: December 30, 1989
    Released on J-STAGE: March 07, 2011
    JOURNAL FREE ACCESS
    Ekman's theory of ocean current driven by wind is reviewed. The theory is confirmed by a simple rotating tank experiment. The visualized flow in the tank fairly fits to the theory. The basic equation is also solved using the impulse response function to answer some basic questions on the curious flow in the rotating fluid.
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  • Mitsuaki FUNAKOSHI, Masayuki OIKAWA
    1989 Volume 8 Issue 4 Pages 311-335
    Published: December 30, 1989
    Released on J-STAGE: March 07, 2011
    JOURNAL FREE ACCESS
    Waves in a stratified fluid are described. First, linear wave theories are summarized for general stratifications. Secondly, mainly for a two-layer fluid, weakly nonlinear theories and fully nonlinear computations for steady progressive waves of large amplitude are reviewed. The similarity to or the difference from the case of surface water waves is also discussed.
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  • Yusuke FUKUSHIMA
    1989 Volume 8 Issue 4 Pages 336-347
    Published: December 30, 1989
    Released on J-STAGE: March 07, 2011
    JOURNAL FREE ACCESS
    The axisymmetric plumes and the axisymmetric jets are investigated analytically. The k-ε turbulence model is adopted in the analysis. Both axisymmetric plumes and jets satisfy the similarity solutions, which are independent on the Reynolds number and the Richardson number. Therefore the similarity solutions are expected to be applicable to the wide range of hydraulic conditions. The velocity distributions of the plume and the jet obtained herein explain well the experimental results. The distribution of relative density difference predicted for the plume also explains well the experimental data. The value of σt =0.4 for the axisymmetric plumes is somewhat smaller than the values of σt=0.8-1.0 for the inclined wall plumes and for the plane plumes. Thus it is concluded that the method of the similarity solutions can be used to obtain the velocity and temperature distributions.
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  • Yu FUKUNISHI, Takanobu OGAWA, Mikio HINO
    1989 Volume 8 Issue 4 Pages 348-358
    Published: December 30, 1989
    Released on J-STAGE: March 07, 2011
    JOURNAL FREE ACCESS
    A temporally growing turbulent plane mixing layer is simulated by “Vortex Stick method”, a 3-D Discrete Vortex Method. The growth of large-scale spanwise vortical structures, and the existence of streamwise vortices are observed. How the streamwise vortices are created from the originally spanwise vorticity components is shown : First the vortical segments change their directions, then they are stretched at the braid region in-between the large-scale spanwise vortices.
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  • Tatsuo NISHIMURA, Shinichiro MURAKAMI, Yuji KAWAMURA, Hisashi MIYASHIT ...
    1989 Volume 8 Issue 4 Pages 359-369
    Published: December 30, 1989
    Released on J-STAGE: March 07, 2011
    JOURNAL FREE ACCESS
    Flow patterns in a symmetrical two-dimensional wavy-walled channel were investigated by flow visualizations at low Reynolds numbers : 10-300. In the case of steady flow, we discovered a new flow structure consisting of a regular three-dimensional flow as the Reynolds number exceeds 27.5. In the case of oscillatory flow, the Reynolds number for transition from two-dimensional flow to three-dimensional flow increases with the Strouhal number.
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  • 1989 Volume 8 Issue 4 Pages 381
    Published: 1989
    Released on J-STAGE: March 07, 2011
    JOURNAL FREE ACCESS
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