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Masao YAMANOUCHI
1955 Volume 21 Issue 101 Pages
1-2
Published: January 25, 1955
Released on J-STAGE: March 28, 2008
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Syoji ITAYA, Toshio TAKENAKA, Tsuruo MIYAZAWA, Akira KUBO
1955 Volume 21 Issue 101 Pages
3-6
Published: January 25, 1955
Released on J-STAGE: March 28, 2008
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The authors determined experimentally the discharge coefficients of pipe orifices of oil flow from one inch to six inches in diameter. Experimental results are shown in Fig.6, and calculated values of the discharge coefficients by the experimental formula (4) are compared with experimental one in Table 2.
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Yoshimasa FURUYA
1955 Volume 21 Issue 101 Pages
6-12
Published: January 25, 1955
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This paper presents an analysis of the two-dimentional incompressible flow in turbulent boundary layer in diverging channel in particular for the effects of adverse pressure gradient on the shape of the velocity distribution. Semi-empirical formulas of the skin friction and the velocity distribution near the wall are expressed in terms of the Reynold's number and a single from parameter K=(u/U)
y=v that fixes the shape of the velocity distribution. By means of these equations and equation of motion, rate of change of the parameter K with x is developed. Comparing this method with the other methods used by previous workers, critical survey is given together.
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Tokio UEMATU, Keiji HATTA, Shigeru YAMAMOTO
1955 Volume 21 Issue 101 Pages
13-17
Published: January 25, 1955
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The method of solving the laminar boundary layer equations by the variational method, which has given an excellent result for the flow along a flat plate, is applied to the retarded flow. The variational problem is solved by Ritz's method. The condition for the stationary value of the functional of the velocity distribution gives a differential equation between the length along the wall and the thickness of the boundary layer, and this equation coincides with the equation of the balance of energy in the layer. Solving this equation, the stress on the wall is calculated as the stationary value of the functional. Some numerical examples are calculated and compared with the known solutions.
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Syoju ITAYA, Yukio TOMITA
1955 Volume 21 Issue 101 Pages
18-21
Published: January 25, 1955
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In order to establish on experimental method by the flowing water channel, we discussed various factors obstructing the analogy between the water flow with free surface and the two-dimensional gas flow. This paper shows that the velocity distributions of the undisturbed flow on a vertical section of the water channel obtained by the calculation are in good agreement with the experimental results.
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Yukio TOMITA
1955 Volume 21 Issue 101 Pages
22-29
Published: January 25, 1955
Released on J-STAGE: March 28, 2008
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In this paper, we show at first that the analogy between the water flow with free surface and the two-dimensional gas flow exists only when the water depth is below 6∼7 mm. Secondly, the method of determination of Mach number is given in the case where the velocity distribution of the undisturbed flow on a vertical section of the water channel is not uniform. Furthermore, it is shown that the inclination of the water tank does not exert any influence upon the approximate analogy.
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Eiji KASAHARA
1955 Volume 21 Issue 101 Pages
29-32
Published: January 25, 1955
Released on J-STAGE: March 28, 2008
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An extension of the Kutta-Joukowski theorem to cascades composed of thin airfoils in subsonic compressible flows holds with sufficient accuracy ; namely, [numerical formula] where L, ω
∞, ρ
∞ and Γ denote lift, velocity of vector mean flow, density corresponding to ω
∞ and circulation, respectively.
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Eiji KASAHARA
1955 Volume 21 Issue 101 Pages
32-38
Published: January 25, 1955
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In this paper the theory developed in the previous report is considerably simplified by using approximate boundary conditions of the same degree with the mapping function. These boundary conditions are able to determine explicitly necessary parameters involved in the mapping function. Thus the solution of 1st. approximation can be obtained in an explicit form. The successive approximation, if necessary, can be carried out to reach results with desired accuracy. Numerical computations are made to cascades of NACA 4412 and Clark Y 6%.
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Nagao MIZUMACHI, Naomichi HIRAYAMA
1955 Volume 21 Issue 101 Pages
38-44
Published: January 25, 1955
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The meanings of loss coefficients that have been adopted by some investigators is considered, and it is explained that they are approximate thrust loss coefficients or energy loss coefficients on some assumptions. The degree of each approximation, when it is applied to two-dimensional flows, is researched by the experiments. In case of two-dimensional measurement, a Pitot tube and a yaw meter are attached parallel, and in case of three-dimensional measurement, both parallel and normal, to the span of blades. The errors caused by two-dimensional measurement being applied to three-dimensional flow are calculated. Results are interesting.
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Atsushi MIYADZU
1955 Volume 21 Issue 101 Pages
45-51
Published: January 25, 1955
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This paper deals with the theoretical study of the pressure rise built up in the liquid trapped between the gears at the meshing point of a gear pump, taking both the local and the convective acceleration of the trapping flow into consideration, the latter of which has been ignored in the author's former paper. The main results are as follows : (1) The convective acceleration has the effect of raising the pressure rise, while the local acceleration has the effect of reducing it. (2) Both effects are comparable and neither of them may be ignored compared with the effect of viscosity. (3) As for the effect only of local acceleration, the present result shows the same tendency and order of magnitude as the former one.
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Masamichi HIRONO
1955 Volume 21 Issue 101 Pages
52-56
Published: January 25, 1955
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The purpose of this research is to solve how the close quantity which is formed between the contact points of gear teeth and the derived quantity of a gear pump are influenced by the amount of profile shift and the system of profile shifting applied to the gear designing. By the analytical study, the following results were obtained. Namely, applying T.NAKADA's Shifting Method, the closed quantity can be decreased distinctly by increasing the amount of profile shift, but this method has a tendency to decrease the derived quantity. While, the shifting method provided in German Industry Norm (DIN) is hardly useful for decreasing the closed quantity, but this increases the derived quantity. Besides, some data of the special involute profile shifted gear which may avoid the evile influence of closing could be obtained.
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Toshio TAKENAKA, Hirotarou NODA
1955 Volume 21 Issue 101 Pages
57-60
Published: January 25, 1955
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The authors gave a design formula of the axis screw pump using optimum depth and helical angle of the screw thread under the laminar theory. Experimental studies were made upon four screws.
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Tomo-o ISHIHARA
1955 Volume 21 Issue 101 Pages
61-67
Published: January 25, 1955
Released on J-STAGE: March 28, 2008
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Applying Euler's theory to the flow in annular circuit and taking the shock-and friction loss into consideration, the relation between the circulating velocity and the input-and output torque of general type hydraulic drive has been deduced. In order to carry out the numerical calculation and to discuss the characteristics of the hydraulic torque converter of all types systematically, a procedure finding out the reasonable arrangement of members in the circuit and the suitable shape of each vane has been derived as follows. Assuming that the shape of each member or vane may be expressed by radii and blade angles at its entrance and exit, and that the flow at the entrance of each member may be shockless at the specific operating condition which is named "reference point, " the energy equation, the shockless flow conditions and the conditions of maximizing the efficiency at reference point are obtained. Accordingly, the characteristics may be calculated numerically and systematically, by using the speed ratio and the circulating velocity at reference point as parameters. By way of example, the quantitative tendency of characteristics of single-stage torque converter for normal operation has been made clear.
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Tomo-o ISHIHARA
1955 Volume 21 Issue 101 Pages
68-73
Published: January 25, 1955
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It has been clarified that the calculating method described in the previous Report is applicable to the cases of multi-stage torque converter and reversing one. Hence the numerical calculations have been carried out to make clear the quantitative tendencies of characteristics of two-and three-stage torque converter for normal operation, and to examine how the reversing torque converter may be put to practical use. As a result, it has been concluded that : (1) Multi-stage torque converter may have higher stall torque ratio than single stage without depressing maximum efficiency. (2) Maximum efficiency of single-stage reversing torque converter may reach about 70% or more, provided that the members are arranged in the order of Pump→Stator→Turbine and the blade angles are suitable.
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Tomo-o ISHIHARA
1955 Volume 21 Issue 101 Pages
74-78
Published: January 25, 1955
Released on J-STAGE: March 28, 2008
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In this Report it has been discussed that (a) any sort of composition of converter circuit is suitable to normal or reverse operation and (b) any distribution of blade angle at leading or trailing edge over the width of flow path brings high efficiency. As the results of numerical calculation and theoretical consideration, it has been concluded that : (a) Pump→Turbine→Stator type is suitable to normal operation use and Pump→Stator→Turbine type to reverse operation, so far as only the single stage is concerned. (b) In order to guarantee that the efficiency of the whole flow path is equivalent to the value calculated on the design path, it is desirable that the condition of flow at the trailing edge of each member satisfies equation (rv
θ)
0=const., where r is radius, v
θ is circumferential component of absolute velocity at any point of trailing edge and suffix 0 represents the reference point.
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Taizo MURAKAMI, Setsuo FUKUNAGA
1955 Volume 21 Issue 101 Pages
78-84
Published: January 25, 1955
Released on J-STAGE: March 28, 2008
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In the first report, we mentioned about the classifying characteristics and its analytical method of our new designed classifier by using the cement powder which is passed through the sieve of 200 mesh Tyler Standard screen. In the above test, the cement powder was classified into four classes. But in the present paper, in order to make clear the foundamental principle with respect to classifying characteristics of our classifier, we further studied and introduced a theoretical fourmula concerning to the efficiency of classification and separable diameter of limit size of dust particle in most simplest case such that the cement powder to be classified into two classes ; the coarse and fine. The experimental results showed that the classifying characteristics of our 2 stages classifier was influenced by the lap of inner and outer pipes of classifier and their diameters, the fixed position of inlet guide vanes, the velocity of upward dust-laden air current, and the mixed ratio of dust-content to air.
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Mitsukiyo MURAKAMI
1955 Volume 21 Issue 101 Pages
84-88
Published: January 25, 1955
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In vibrations of the draft tube, there is a vibration of which frequency varies as the circulation of water, flowing through the tube. In this report, the author has investigated experimentally and theoretically how the character of the vibration changes in accordance with forms of the tubes, such as a conical type and a cylindrical one. If the circulation of water decreases to a certain limit this vibration is apparently observed no more. Some explanations are also given about the fact.
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Fumiki KITO
1955 Volume 21 Issue 101 Pages
89-93
Published: January 25, 1955
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We take up the case of hydro-electric power station having a branched penstock, which consists of a main pipe and two branch pipes connected to the main pipe. To each downstream end of branch pipes, water turbines are connected. At water-turbine side, a pressure-wave is generated (caused, for example, by vibration of water column in draft-tube) and this pressure wave propagates along the penstock. The Author has made a theoretical calculation of the distribution of amplitude of this pressure wave, along the length of penstock, for various frequencies and load conditions at turbine side. The result of calculation is shown by graphs.
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Syoju ITAYA, Toshio TAKENAKA
1955 Volume 21 Issue 101 Pages
94-96
Published: January 25, 1955
Released on J-STAGE: March 28, 2008
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The discharge coefficients K of oil flow of the 60° triangular weir were measured by authors. Experimental formula of K[formula (9)] correlated to Reynolds number coincides with the experimental results as shown in Fig.5, where B is the width of the channel.
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