The experimental results concerning the plastic behaviour of metals along the strain path with a corner have demonstrated some common and fundamental features of the induced plastic anisotropy of polycrystalline metals, for example, the fading memory, the saturation property of prestrain effect and the delay effect. It is shown that the mechanism of the induced plastic anisotropy is closely related with the internal stress due to the interaction among grains of deformed polycrystalline metals and the common features are related closely with the internal stress. Computations using a simple mathematical model of polycrystal proposed in relation to the idea of internal stress show a very good qualitative agreement with the experimental results obtained from some typical strain paths by using a thin-walled tubular specimen of brass.

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A new conformal transformation technique is applied to calculate the two-dimensional incompressible potential ; flow through a cascade. The cascade of arbitrary blades is conformally transformed into a row of circular cylinders and a general complex potential flow is obtained in the mapped plane by applying a perturbation method. The mapping distortion between the physical plane and the mapped plane, as the result of applying this new transformation, is exceedingly small. Therefore, the flow through a cascade whose solidity and/or stagger angle are high can be analyzed more accurately by this method than by the conventional methods ; namely, the method to transform the cascade blades into a single circular cylinder or into two concentric circular cylinders. In addition, the convergency of a series of this new transformation function is not affected by the cascade arrangement.

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This paper describes the effects of types of an approaching flow on the performances of straight conical diffusers. Also, the relationships among inlet boundary layer thickness, inlet swirling components and diffuser performances are investigated. Tests are carried out on straight conical diffusers with total divergence angles ranging from 6° to 18° and with diffuser area ratios ranging from 2.1 to 15.9. According to the result, good performances are obtained if the approaching flow has a symmetrical axial velocity profile with one directional swirling component or a distorted axial velocity profile with double spiral swirling components, and the performances are not so good if it has a simple distorted axial velocity profile without swirling components or with one directional swirling component.

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When a plane moving shock wave encounters an inclined wall, it is reflected by the wall. In these reflection problems, four different types of reflection have been observed in previous shock tube experiments. Namely, they are regular reflection, single-Mach, complex-Mach, and double-Mach reflections. However, in regard to these reflections, there are many questions which are not yet resolved. In the present study, the reflection phenomena of the shock waves have been investigated experimentally over a wide range of incident shock Mach numbers and wedge angles using air or chlorofluoro-carbon (Freon-12), as a working gas. In the experiment using Freon-12, a new type of reflection which cannot be classified into any one of the above four types has been observed. The domains where these five types of reflection can occur and the transition boundaries from one type of reflection to another have been discussed.

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Distorted pressure histories in a linear tapered tube equipped with a tank at the end are experimentally investigated by the step pressure input. And also this problem is theoretically solved by two methods, i.e., eigenfunction expansion and asymptotic expansion. The peak pressure in the tube can be controlled by the capacity of the tank. Large capacity leads to an open end situation. The height of the pressure wave is proportional to the inverse of the tube radius. A one dimensional wave equation including the viscous term in the equation of motion and the effect of the variable cross section is simplified by special transformation, and the simplified equation is solved by the method of the Laplace transform. The resultant analytical solution has a clearer representation than Schuder-Binder's solution.

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The instantaneous velocity distributions and pressure gradients in a reversing pulsatile flow and an oscillatory flow in which turbulent bursts follow by relaminarization in the same cycle are investigated. They are predicted with sufficient accuracy by the theory for a transient pulsatile laminar flow in the laminar phase. Meanwhile, in the phase where turbulence with higher frequency appears, they are well approximated by the well-known 1/7 power law and the turbulent quasi-steady friction law respectively.

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The equations governing the motion of viscous fluid across a plate orifice in a U-shaped tube are presented for laminar and turbulent regimes, respectively. Unsteady resistance across a plate orifice is assumed to be composed of two parts. One is proportional to acceleration of fluid and the other to the square of cross-sectional mean velocity. The coefficients in the expression for resistance are determined on the basis of the experiments made here or referring to the previous investigations in steady and unsteady flows. Within the range of the present experiments, the numerical results calculated by assuming that the unsteady resistance across a plate orifice is represented by the well-known quasi-steady relation agree well with the present observations made with video camera.

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The response of a hydraulic copying system degrades when input frequency increases beyond the break frequency of the system. Providing another flow input directly to the power cylinder of the copying system, the output displacement can be improved in a frequency range between the break frequency and the natural frequency of the hydraulic copying system. A new dislacement type flow generator was invented to supply the flow input, and combined with a hydraulic copying system. The new copying system was applied to turn an elliptical piston of automobile engines, where a fast reciprocating motion of cutting tool is generally required. The static and dynamic characteristics of the device coincided well with the theory in this paper. The results of machining were sufficiently accurate in all of test runs over half a year.

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The concept of negentropy was introduced with the intention of physically describing such terms as information, order, non-equilibrium and potential of work. Negentropy according to the new definition which was proposed in the preceding report represents those terms more adequately than according to the former definition. Among those terms, this report mainly intends to develop the relation between the negentropy according to the new definition and potential of work, and in this sense it means an application of negentropy to the field of thermodynamics. In this report, the problem how the negentropy moves among systems in the form of work, heat, or the change of volume is considered, then how the maximum work which can be taken out of a system is determined by the negentropy in the system is also considered, and further, the relation between negentropy and exergy is discussed.

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Experimental investigation was made into circumferential distribution of thicknesses of liquid film formed on the inner surface of a horizontal tube of 26.0 mm I.D. in which air and water flowed concurrently. Superficial velocities of both phases ranged 10∼50m/s for air and 0.006∼0.40m/s for water. The flow pattern concerned was mainly annular flow. The main results obtained are summarized as follows : (1) circumferential distributions of such film thicknesses as the mean, the maximum and the minimum are empirically formulated ; (2) two methods utilizing needle contact and constant current are compared for the measurement of film thickness, and both results are in satisfactory agreement ; (3) film thickness averaged over the entire circumference of the tube is approximately equal to the local mean film thickness at an angle θ=120°measured from the top of the tube cross section ; (4) the data of pressure drop and hold-up are sufficiently correlated by Lockhart-Martinelli parameters.

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The authors investigated possible influences of combustion chamber configuration on the engine performances displayed through the use of emulsified fuel. To modify the configuration of the combustion chamber, an adapter is fitted to the entrance of the BIP-type combustion chamber of a direct injection diesel engine. As a result of experiment, it was confirmed that the combustion chamber configuration with lower flow-through velocity at the combustion chamber entrance has a remarkable effect of reducing the NOx concentration and BSFC.

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In a rotating asymmetrical shaft carrying an asymmetrical rotor, there occur two types of unstable regions. These unstable regions change with the orientation angle ζ between the inequality of shaft stiffness and that of rotor inertia. The conditions under which unstable vibrations occur just as input energy into the rotating shaft system tends to increase the whirling amplitudes of the shaft, can be clearly ascertained. These conditions, which depend on the angle ζ, tend to show a good coincidence with those obtained by an analog computer. Moreover, when asymmetrical shaft stiffness Δ_ij and asymmetrical rotor inertia Δ₀ are chosen suitably, two types of unstable regions are eliminated.

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Various types of axisymmetric nonlinear forced oscillations are expected to occur in a circular plate subjected to harmonic excitation. The present paper concerns among others the summed and differential harmonic oscillations. Both theoretical and experimental analyses are conducted. The theoretical analysis, based on the von Karman equations, reveals that the oscillations can occur when the linearized natural frequencies p_n(n=1, 2, 3, ...) and the excitation frequency ω satisfy one of the following conditions : ω≒p_i+p_j, ω≒2p_i+p_j, or 2ω≒p_i+p_j The characteristics of the oscillations for each of these cases are obtained. The experimental analysis, performed by use of a steel plate, also ascertains the occurrence of the oscillations for all the cases predicted by the theory. The characteristics of the oscillations obtained by the theory and experiment are found to agree reasonably.

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In this paper, the authors investigate the axisymmetric vibrations of a vessel with variable thickness composed of a cylindrical shell and two circular plates as its lids. They obtain the Lagrangian of the vessel expressed by quadratic forms of unknown boundary values and obtain the frequency equations from the minimum condition of the Lagrangian. Effects of the variations of thickness of circular plates and a cylindrical shell, of the length of a cylindrical shell etc.upon natural frequencies and mode shapes are clarified in discussions of numerical results.

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It is a purpose of this paper to present a means of handling both turbulent and inertia effects on the dynamic characteristics of finite width journal bearings. In the analysis turbulence is treated by means of turbulent coefficients and inertia forces are approximated by mean velocities averaged across the fluid film. Assuming a small displacement of journal center, the dynamic coefficients such as spring, damping and acceleration coefficients and the onset whirl frequencies of rotors are computed The results obtained show that the dynamic characteristics as mentioned above are affected by inertia forces.

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An analytical method of two-dimensional vibration of interacting columns for aseismic design of a high temperature gas-cooled reactor core with block-type fuel has been developed. In the analytical method, blocks are treated as rigid bodies and a spring dashpot model is used for the collision process between blocks. Analytical results are compared with experimental ones and both are found to be in good agreement. The analytical method can be used to predict the behavior of the high temperature gas-cooled reactor core under seismic excitation.

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The purpose of the present paper is to examine the influence of centrifugal force on stresses at each position of a force-fitted gear under running condition, and to discuss on safe designing of a force-fitted gear when the influence of centrifugal force is considered. The following conclusions are obtained. (1) The stress caused by centrifugal force becomes maximum at the position where the center line of tooth space crosses the root circle, and the stresses at each position of gear and the decrease of interference at force-fitted surface are proportional to square of number of revolutions. (2) A practical formula to decide the maximum stress, the fillet stress at the position where Hofer's weakest section crosses the trocoid curve at the root fillet of tooth and the decrease of interference can be introduced.

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A device to produce pistons with elliptic cross section has been developed. The device is mounted on a lathe. Principal part of the device consists of two copying syetems, one of which controls the mean position of a turning tool, and the other controls the amplitude of oscillating motion of the turning tool. Design values of a piston shape will be expressed on two templates which are followed by the hydraulic copying systems. A method of measurement and data analysis based on the finite Fourier series on the cross sectional figure of a turned piston is also discussed. Inspection on the produced piston based on the discussed method of analysis and measurement revealed good accuracy of the turning.

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Strengthening of pressed components has recently been reqired to husband natural resources and save energy. Unfortunately, any strengthening of sheet metals generally causes a decrease in their ductility and formability. Therefore, it is very important to find out the optimum forming conditions. In the present study, the optimum conditions for increasing the critical forming depth in pure stretch forming are clarified, using several punches with an ellipsoidal profile, seven kinds of sheet metals and four kinds of lubricants. The optimum punch profile and the optimum frictional coefficient for increasing the critical forming depth were found by both numerical analysis and experiments. In addition, it was confirmed that the critical forming depth could be increased by applying a low friction lubricant (PTFE and Bright stock) to the central region of the punch and a high friction lubricant (Rosin) at the outer region.

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