KAGAKU KOGAKU RONBUNSHU
Online ISSN : 1349-9203
Print ISSN : 0386-216X
ISSN-L : 0386-216X
Volume 2 , Issue 4
Showing 1-18 articles out of 18 articles from the selected issue
  • Akira Kanagawa
    1976 Volume 2 Issue 4 Pages 325-330
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A discussion based on exact Mie theory calculations is given on light scattering aerosol measurements for absorbing aerosol particles. From the calculations of Mie's scattering light intensity functions for absorbing particles as a variable of imaginary part of refractive index, it has been found that the scattering light intensities vary abruptly with the variance of imaginary parts in the region from 0 to 0.2 of their value. Response calculations for the aerosol particle photocounter for particle sizing and the aerosol photometer for particle concentration measurement have been made for absorbing particles. As a result, it is pointed out that one should take into account the absorbing properties of aerosol particles on the light scattering aerosol measurement, particularly when the particle size is greater than 1 μm.
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  • Akira Kanagawa, Takeshi Takahashi
    1976 Volume 2 Issue 4 Pages 331-335
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A Owl-type photometer designed for measuring the particle size of monodispersed submicron particles was constructed and has been used experimentally for polystyrene latex hydrosols. The angular dependency of the ratio R1 of the long-wavelength scattering light intensity vertically polarized to the short one are measured and compared with the theoretical relations calculated from Mie's scattering theory.
    As a result, it was found that the pattern of the angular dependency of R1 varies regularly with particle size, and this photometer seems to be capable of the size determination roughly of monodispersed particles in hydrosols.
    Quite similar studies of the angular dependency of the polarization ratio of the scattering light were made also, and similar results were obtained.
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  • Hideto Yoshida, Takeshi Ohsugi, Hiroaki Masuda, Shinichi Yuu, Koichi I ...
    1976 Volume 2 Issue 4 Pages 336-340
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    To examine the error in measuring particle concentration due to anisokinetic sampling over a wide range of inertial parameters, theoretical and experimental studies have been conducted using methyleneblue-uranine aerosol generated by a spinning disk and lycopodium spores in the small and large inertial regions respectively. Theoretical results obtained under the assumption of potential flow are in good agreement with experimental data, and estimation of anisokinetic sampling errors may be possible. It is also recognized that concentration error becomes smaller as the sampling velocity becomes extremely high. The amount of particles deposited in the probe is also examined and interesting results are obtained such as the fact that the deposit shows the minimum value at Reynolds numbers from 2, 000 to 3, 000 and that the amount of particles deposited in an acrylic probe is larger than in a brass one.
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  • Koichi Iinoya, Kazutaka Makino, Yasushige Mori, Jun-ichi Okutani, Hiro ...
    1976 Volume 2 Issue 4 Pages 341-346
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Dust cleaning performance of collapse and mechanical shaking types of fabric filters were experimentally investigated. In the collapse type, dust scaling off occurs only in the initial cleaning stage, and part of the secondary dust layer remains on the filter surface despite infinite cleaning. The existence of an optimum local cleaning duration is found experimentally and can be estimated. In the mechanical shaking type, dust scaling off occurs throughout the whole cleaning process, so that the secondary dust layer is almost completely dislodged. For a fixed cumulative cleaning duration, division into shorter rather than longer local cleaning duration was found more effective.
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  • Tohru Niida, Tetsuo Yoshida, Kei Nishii
    1976 Volume 2 Issue 4 Pages 347-354
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Hydrodynamical characteristics of viscous, incompressible flows in cavities may be required to design scraper-type heat exchangers and reactors often used for processing very highly viscous fluids.
    In this work, stream functions and velocity components are obtained numerically by mean of a relaxation technique, for two-dimensional viscous flows in annular sectors bounded by a pair of co-axial circular walls (radii ratio, η) and by two radial walls (opening angle, 2α), of which the outer circular wall is rotating at a constant angular velocity.
    Results obtained here can be shown with some typical flow patterns according to the aspect ratio (1-η)/2α. In each flow pattern the circulation rate, location of the vortex center and stream functions are correlated with the radii ratio and the opening angle of the angle sector by the special values of the circulation rate, location of the vortex center and others.
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  • Kunio Kato, Yukio Osawa, Yukio Hiraishi, Junichi Funatsu, Utaro Ito
    1976 Volume 2 Issue 4 Pages 355-359
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    When the particles were fluidized with gas in columns packed with open-end cylindrical screen packing, the lowest pressure drop of the gas distributor which was required for good fluidization was measured. This pressure drop is defined as the critical pressure drop for good fluidization. The critical pressure drop in a screen-packed fluidized bed is influenced by the minimum fluidized gas velocity, bed diameter and fraction of open area in the distributor plate. Empirical correlations for critical pressure drop in the packed fluidized bed were obtained.
    When the particles were fluidized with gas under different fractions of open area in the gas distributor, the critical pressure drop decreased until a constant value was reached. This constant critical pressure drop is defined as the terminal critical pressure drop for good fluidization.
    In this study, empirical correlations for critical pressure drop in these two regions were obtained. At the same time empirical correlation between the pressure drop of a perforated gas distributor and operating conditions was obtained.
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  • Hajime Unno, Ichiro Inoue
    1976 Volume 2 Issue 4 Pages 360-365
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The behavior of an oil film on calm water surface in the surface tension-controlled time period was studied experimentally.
    Velocity distributions of oil film were measured by tracing the positions of talcum powder laid on the film surface. The maximum velocity was found in the intermediate region between the center and the periphery of oil film.
    The velocity distributions of oil film can be classified into two cases. One is the case where the relative velocity distribution is independent of time and the other is the case where it varies with time, where the relative velocity is defined by the velocity relative to the value at periphery of oil film. These two velocity distributions can be discriminated by a parameter which is the product of the oil viscosity and the final thickness of oil film divided by the spreading coefficient of oil film. The time dependency of the spreading velocity of oil film is concluded to vary with the type of velocity distribution.
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  • Yukinari Sato, Kazuo Yamamoto, Tokuro Mizushina
    1976 Volume 2 Issue 4 Pages 366-372
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    The laser Doppler technique for measuring fluid velocity has been investigated and developed by many groups of workers. It has several advantages over the other conventional methods, such as the Pitot tube and hotwire anemometry. By this technique, measurements of instantaneous local velocity components can be performed for fluid flow speeds lying between about 10-3cm/sec and supersonic velocities, without the insertion of a disturbance-producing probe into the fluid. However, the recent commercial instruments are very expensive.
    The authors constructed a simple and inexpensive instrument, which comprised He-Ne laser equipment, an optical system and a signal processing system. In this paper, details of the instrument and a few examples of measurements are described.
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  • Masaki Minemoto, Masayoshi Sadakata, Daizo Kunii
    1976 Volume 2 Issue 4 Pages 373-379
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    It is well known that Reynolds stresses which are expressed as double correlations of velocity fluctuations are the main controlling factors of momentum-transfer rates in a turbulent field. A universally applicable Reynolds stress model is required in order to describe the flow pattern in a turbulent flow. This study is aimed at making clear the applicability and universality of conventional phenomenological Reynolds stress models.
    A two-dimensional turbulence in homogeneous shear flow (Couette flow) being chosen as the simplest turbulent shear flow field, effects of turbulent eddy scales and time-mean velocity gradient on a Reynolds stress were investigated analytically and experimentally. Two conventional representative Reynolds stress models, namely a Kolmogoroff-type model and Bradshaw-type model, were compared with experimental results. The following conclusions were obtained.
    i) Where the velocity-gradient of time-mean flow is extremely smaller than that of turbulent eddy, the Kolmogoroff-type model is applicable.
    ii) Where the velocity-gradient of time-mean flow approaches that of turbulent eddy, both the Kolmogoroff-type model and the Bradshaw-type model are applicable.
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  • Takeichiro Takamatsu, Iori Hashimoto, Hirokazu Nishitani
    1976 Volume 2 Issue 4 Pages 380-386
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    A new optimization technique called the max-sensitive method has been developed for a class of single output optimization problems, that is, to obtain the optimal solution A* which minimizes g (A) subject to Ai≥0 (i=1, 2, …, n) when one system output Xout (A) =f (A) has been specified. Initially, the family of problems is formulated in which the original problem is imbedded. “Maximize Xout (A) =f (A) subject to Ai≥0 (i=1, 2, …, n), and g (A) ≥t, where t is increased from a lower bound t0 to an upper bound, tf.”
    The optimal solutions of this family of problems form an equi-sensitive line on which the sensitivities Si= (∂f/∂Ai) / (∂g/∂Ai) become equal to each other. A new algorithm for following the equi-sensitive line is presented, and the optimal solution of the original problem is then easily obtained. As well as the theoretical aspects of the method, numerical considerations of practical design problems are included. By applying this method to the design of complex heat exchanger systems, it has been shown to have many distinct advantages.
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  • Hisao Nakai, Hiroshi Shoji, Yoshiaki Yamada
    1976 Volume 2 Issue 4 Pages 387-393
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Uneven settlement of oil storage tanks has been a big social problem since heavy oil flooded into the Setonaikai Sea by an accidental oil tank rupture. Therefore, we tried to analyse the stress induced in an oil storage tank which has a record of uneven sinking into the foundation. The settlement of an oil storage tank which was constructed on December '61, and had shown uneven sinking when full of water is reexamined minutely and the data are used as input for the displacement constraint at the element node of the bottom plate in computer analysis. The verification of the program is carried out by solving for a circular plate on elastic foundation and under concentrated load.
    A detailed stress and deformation analysis is carried out by the finite element method. Numerical results elucidate the feature of deformation and stress distribution, and it is found that the maximum shearing stress exceeds the yield point in the annular region of the bottom plate. Thus welded specimen models of the most heavily stressed part are built and bending as well as fracture tests are conducted to assess the allowance for safety of the storage tank.
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  • Yasuharu Akagi, Tamiya Kishimoto, Teruo Takahashi
    1976 Volume 2 Issue 4 Pages 394-398
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    This study relates to establishing a forecasting method for conditions of air pollution at a seaside industrial area. Using data measured in the Mizushima industrial area, we investigated the relation of weather conditions and SOx concentrations. The distributions of SOx concentration were calculated by the plume model at the weather condition in which this area was polluted. And the optimum parameters of the plume model by which the error between measured and calculated SOx concentration became smallest were obtained. It was found that the optimum parameters could be correlated by the wind velocity.
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  • Masanobu Matsumura
    1976 Volume 2 Issue 4 Pages 399-404
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Experimental studies were conducted in a vibratory cavitation erosion facility at a frequency of 19.9 kHz and double amplitude of 28 μm for metals including aluminium, brass, iron and steels. Observing the life history of eroded holes on the specimen and of a certain single hole as well, two different types of damage were found and the following conclusions were obtained. (1) The mechanism of cavitation damage on the metals changes them from ductile to brittle with the lapse of testing time. A dimensionless number was introduced as a quantitative criterion to identify the degree of cavitation damage. (2) This transition of the mechanism depends upon the experimental conditions as well as upon the properties of the specimen. (3) A part of the variation in erosion rate is caused by this transition of cavitation damage mechanism.
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  • Masanobu Matsumura, Ken Tsuda
    1976 Volume 2 Issue 4 Pages 405-409
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Effects of experimental conditions of the vibratory erosion test upon the damage caused by cavitation erosion of metals were investigated. By use of a dimensionless number as a quantitative criterion of cavitation damage, the following conclusions were obtained. (1) Amplitude of vibration and diameter of test specimen exert decisive influence on the rate of erosion but not at all on the degree of damage. Temperature and pH of test liquid (corrosiveness of the test liquid), frequency of vibration and pre-strain on the specimen have influences on the degree of damage as well as on the rate of erosion. (2) In a vibratory cavitation erosion test it is quite feasible that damage may be caused to metals by any desired mechanism. Some characteristic features of damage were also revealed.
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  • Toshihiro Nakai, Kenji Tatsumi, Yoshio Sato, Kohei Urano, Hiromichi Yu ...
    1976 Volume 2 Issue 4 Pages 410-415
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    For the case of adsorption treatment of waste water with fixed bed, a calculation method for estimation of breakthrough curve was investigated.
    As each component in waste water is unknown, the breakthrough curve and the replacing adsorption zone for each component cannot be estimated. But it seems possible to estimate the breakthrough curve with the mean adsorption characteristics based on total organic carbon concentration for a substantial adsorbable component, applying the method indicated by K. Kawazoe.
    Using dyestuff synthetic waste water, these points were examined and the calculated curve nearly agreed with the experimental.
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  • Isao Endo, Ichiro Inoue
    1976 Volume 2 Issue 4 Pages 416-421
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Metabolic coefficients in a living system were elucidated in the form of a signal flow diagram. Based upon negative signs of the coefficients, an analytical method was proposed to predict both enzyme activities in loops and conversion amount at a confluent point in metabolic pathways.
    It was found that enzymatically activated loops and confluents varied depending on the growth phases in batch culture of yeast cells, i.e. adaptive, accelerative, logarithmic and stationary. It was also observed that the metabolic activities of yeast cells changed radically with some intervals of time. Predicted enzymatic activities in loops and confluents were discussed and compared with the other experimental data reported.
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  • Noriaki Wakao, Shigeharu Tanisho, Bunro Shiozawa
    1976 Volume 2 Issue 4 Pages 422-425
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
    Thermal response experiments were conducted for packed beds at low Reynolds numbers (Re<6). The experimental temperature signals (temperature-time curves) were compared with the theoretically predicted signal curves, and it was found that the axial thermal dispersion coefficients were anomalously high compared with the gas thermal diffusivity value.
    The particle-to-gas heat transfer coefficients were also found to be large; Nusselt numbers were not to be less than 0.1 at Reynolds numbers less than six. Interpretation was made for the reason of high axial thermal dispersion coefficients.
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  • Masabumi Nishikawa, Kumekazu Ashiwake, Noriaki Hashimoto, Shinji Nagat ...
    1976 Volume 2 Issue 4 Pages 426-431
    Published: July 10, 1976
    Released: October 21, 2009
    JOURNALS FREE ACCESS
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