A plane-strain compression test was made to investigate the Bauschinger effect in aluminum single crystals which deform by multiple slip. First, the testing method, especially as to the clearance and the lubrication between crystal and die, was discussed in comparison with torsion test. The Bauschinger curves of crystals with various non-symmetrical orientations were represented by the shear stress and the shear strain determined from the forward and the reverse compression data using the analysis of Taylor-Bishop-Hill. Here, in the reverse compression the free plane of crystal in the forward compression was compressed without changing the restricted plane. The analysis did not always produce satisfactory results in the permanent softening. This is due to the lattice rotation during deformation. Nevertheless, the average curve of single crystals was found to be in good agreement with the Bauschinger curve of polycrystal. Furthermore, the dislocation structure was examined by transmission electron microscopy and also an examination of slip system derived from the analysis was tried.

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In this paper an elastic stability analysis has been developed for spherical shell segments with fixed or horizontally removable edges. The shells are subjected to external hydrostatic pressure or the combination load, namely, hydropressure and frictional resistance. And when these forces act nonconservatively on the surfaces of the shells. It is shown, the dynamic (flutter type) instabilities as well as static (divergence type) instabilities often take place. The authors consider that these analytical results give some contributions to the study of elastic shell stability.

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A frictionless axisymmetric contact problem is considered of an elastic layer which is resting on a rigid base with a cylindrical protrusion or pit and is indented by a rigid stamp. The problem is reduced to a solution of two infinite systems of simultaneous equations by the assumption that the normal displacement on the lower face of the layer may be expressed as an appropriate series. The size of the contact area and the distribution of the contact stresses are studied, and some numerical results are obtained.

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In measuring in-plane deformation by using diffraction beams, fringes corresponding to contour lines of various strain components can be obtained. Measurement of normal strain (or the first order derivative of displacement) is rather simple, and the authors reported on the method for it already. In this paper a new method of measuring shear strain is proposed, in which a modified Sciammarella's optical system (1967) is used and the double exposure processing is applied. In this method sensitivity in measurement is twice that of the recent moire method using diffraction beams, or 6 times that of the conventional moire method using interference of grating lines. Further, errors in moire fringes due to mis-adjustment of an optical system, non-uniformity of thickness of film (specimen grating), etc. are compensated almost completely.

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The pressure distributions of hydrofoils in dilute polymer solutions were measured. The cross sectional shapes of hydrofoils were NACA-0006 and NACA-2412 profiles. The differences between the characteristics of hydrofoils in dilute polymer solutions and those in pure water were classified. Furthermore, the mechanism of the change in characteristic was investigated by measuring the velocity distribution in the boundary layer with a Laser Doppler Velocimeter. The results show that the performances of the foils depend on the development of a boundary layer. The lift coefficient of NACA-0006 section increases and its drag coefficient decreases because of a decrease in scale of a separation bubble on the suction side. The lift coefficient of NACA-2412 section decreases at small incidence angles because of an increase in thickness of the boundary layer, and increases at larger incidence angles due to a downward movement of the separation point.

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On the basis of subchannel analysis, a simple model to predict the flow distribution and the pressure drop for a turbulent flow through rod bundles is developed. The model is applicable to an isothermal, fully developed flow. The most significant feature of it is that the geometry factor of a turbulent flow for a subchannel is evaluated from that of a laminar flow. The proposed model is tested by the experimental data of the other investigators as well as the authors. The calculated values of the flow distribution and the pressure drop are in good agreement with the experimental data. The dissipation of energy due to wall friction in a rod bundle is discussed. The result shows that the condition of the minimum dissipation is equivalent to that of equal frictional pressure gradient in each subchannel.

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Flow characteristics of a two-dimensional air jet issuing from a nozzle of 5mm in height and impinging against an inclined wall, which has the vertical distance L between its leading edge and the jet axis plane and an angle θ of 15°-45° against the plane, have been experimentally and analytically investigated. The maximum velocity profile in the flow direction was predicted semi-theoretically in the upper stream area and analyzed in the wall jet area by the same numerical method as taken in our previous report. The momentum flux decreases along the wall owing to the impingement and so on, the coefficient of the momentum decrease ηm at the cross section of s/t=140(s:distance along the main stream line, t:nozzle height) is in the range of 0.85 to 0.55.

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The primary concern of this paper lies in providing an exact description to the transitional wave flow in the 'transient' end correction problem. For this purpose, attention is first paid to propagation of a transient 'non-plane' wave in a tube generated by a step change of its cross-section. The multi-mode wave equation is applied to the analysis together with the Laplace transformation, yielding series expansions by Bessel functions as solutions. After the transient properties of an indivisual higher-mode wave are made clear, some intriguing behaviors of the entire non-plane wave in a tube are also revealed. With a tube radius infinitely augmented, these results turn out useful for describing an expanding wave flow around an aperture in an infinite plane wall. Finally the pressure and velocities in the flow are determined in terms of definite functions through reduction of the infinite series.

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In this paper numerical analysis has been performed on mass transport from daughter channel wall to pulsatile flow through a two-dimensional orthogonal branch. The transport of a substance such as cholesterol from artery to blood flow is modeled, and is examined by numerically calculating the nonlinear mass transport equations for convective and diffusive processes. Particular attention is paid to the variation of mass transport at the separated region on the daughter wall of branch. The steady flow is calculated so that the effects of pulsation can be assessed. Consequently, the following results are obtained: 1. The mass transport is strongly dependent on flow region and pulsation. 2. Reduction of the mass transport occurs at the separated region on the daughter wall of branch. 3. In a simple pulsatile flow, the mass transport at this separated region on the daughter wall steeply changes at the time when the flow rate increases from zero flux.

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As a means for an augmentation of heat transfer, a strip 10 mm wide was inserted in the turbulent boundary layer on a heated plane surface. Distributions of the local heat transfer coefficient on the plane surface were measured when both the inclination angle of the strip φ and the clearance c between the surface and the strip were varied. When the clearance is increased while keeping the angle φ constant, the distribution of local heat transfer coefficients undergoes similar changes in distribution pattern irrespective of the angle φ, although the magnitude of the clearance causing the change in the pattern is different. The mean heat transfer coefficient over a surface of length x^^- downstream from the strip varies with x^^-, and the mode of variation depends heavily on the clearance and the inclination angle. One of the most preferable distributions in this experiment was obtained when φ=45° and c=4 mm.

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A simple theoretical model is proposed for flow patterns around the louvers of compact heat exchangers in air-conditioners. The purpose of this paper is to determine the louver arrangement having the highest heat transfer coefficient and the lowest static pressure drop. Experiments using a scaled-up modeling technique employing thermistor plates point to the existence of a specific fin configuration and louver angles that bring forth optimum heat transfer and static pressure drop characteristics. Performance of a newly-designed, inclined louvered fin and a flat tube heat exchanger was clarified using a steady state hot water-to-air testing technique. The heat transfer coefficient and static pressure drop of an optimally inclined louvered heat exchanger is 16% higher and 2127% lower than those for conventional louvered heat exchangers.

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Rapid combustion of lean mixtures in a spark ignition engine is a concept promising for the fuel economy as well as the emission control. Torch ignition and/or the use of nonhomogeneous mixtures such as a stratified charge may be the means of their rapid burning. The flame propagation characteristics of nonhomogeneous mixtures were experimentally estimated by a constant volume combustor equipped with a single-shot fuel injection system and a prechamber. This combustor enabled preparation of various nonhomogeneous states of the mixture to be burned by a torch. It was found in such a nonhomogeneous state a formed by the direct injection of fuel that even fairly lean mixtures could be burned as rapidly as the stoichiometric mixture.

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A novel laser diffraction technique is applied to an investigation of spray vaporization phenomena in hot gas stream. Measurements are made of local droplets size and their distribution in volume element within a quasi two dimentional spray generated from Fan Spray nozzle. The results indicated that the uniformity of the size distribution is improved under the vaporizing conditions in hot down gas stream. The presented technique provides information and useful data on spray vaporizing processes and it will be useful in studying the spray vaporization model and combustion model.

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A measurement method for spray droplet evaporation rate constant was shown. In this study a novel laser diffraction technique was applied to the investigation of spray vaporizations. Measurements were made of local spatial size and distribution in volume element within a quasi two dimentional spray generated from Fan Spray nozzle. Detected diffracted total light energy and its relative diffracted light energy were defined. To predict the evaporation rate constant, the detected relative light energy was compared with the total light energy in vaporizing spray in hot gas stream. For ethanol cloud spray, evaporation rate constant was given as 0.04-0.1mm²/s (373K-573K). It is found that this method is available to estimate the evaporating rate constant of liquid spray.

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In a small type spark ignition engines with carburetor, the mixture strength charged into the cylinder, that is, the combustion state and the exhaust characteristics under transient running are remarkable influenced by instantaneous behavior of the fuel liquid-film flowon the inner wall of intake pipe. Accordingly, the authors carried out some experiments and numerical analysis in order to clarify the instantaneous mixture formation in cylinder, under the transient operation as the carburetor throttle valve is stepwise closed.

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An application of solutions of linear Mathieu equation by a new method gives approximate solutions in a parametrically excited self-excitation system with dry friction. Steady solutions and the stability in the regions of parametric resonance of first and second orders are determined. Solutions outside the regions of parametric resonances are approximated by two limit cycles. One corresponds to a stable solution and the other corresponds to an unstable solution. Beyond a certain value of dry friction self-excited vibrations are completely suppressed and a parametric resonance of second order soon disappears, so that only a parametric resonance of first order remains within a certain interval of frequency. Numerical results by the present analysis almost agree with those by Runge-Kutta method and it is seen that the proposed approximate methods have high accuracy.

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In parametrically excited self-excitation systems with dry friction, approximate solutions outside the regions of parametric resonance of second order are obtained and it is ascertained that they are reasonable approximate solutions. Approximate solutions in the neighborhood of parametric resonance of firs order are obtained and critical frequencies where beat vibrations occur and disappear can be determined by the points of intersection of these solutions and parametric resonance curves of first order. By numerical results it is ascertained that this determination method of critical frequencies has high accuracy and the interaction between parametric excitation and self-excited vibration is discussed.

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This paper is concerned with the coupled lateral-torsional vibration of rotors trained by gears. First, numerical calculation technique using transfer matrix method is presented to obtain both free and forced vibrations, where, for the simplicity of analysis, tooth rigidity is assumed to be a linear spring, and backlash and tooth profile error are neglected. Then the numerical calculations were carried out in three cases; (1) the force acting on the contact line is only a function of rotations at gears, (2) the force acting on the contact line is a function of both the rotations and the flexure at gears, and (3) two rotors are not coupled. The eigenvalues, eigenmodes, and the responses of unbalanced mass are calculated and the results are discussed.

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This paper deals with rotor vibration caused by seismic wave, the influence of gyroscopic force on the response and an aseismic design method using a stopper with clearance. An analysis is presented for calculation of the response of a general flexible rotor excited by an arbirtary external force such as seismic wave. Modal techniques and step by step numerical integration are employed. The calculation method is applied to a rotor with a strong gyroscopic force. The computational results of a harmonic excitation indicate that there exist two resonance frequencies corresponding to forward and backward whirl motions. The numerical history response indicates that even non-circular one-directional stopper is sufficient for aseismic design to keep the clearance induced vibration small. A pump rotor is chosen to demonstrate the seismic resonance of a rotor with a weak gyroscopic force. Then the pump rotor dynamics become very similar to structural dynamics. but the clearance induced vibration of pump rotor exhibits a whirl orbit motion which characterizes the rotor dynamics.

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By way of basic research on vibration and noise of internal combustion engines, the vibration analysis of the piston-crank system of an engine is made. The piston-crank system is composed of three substructures, namely a piston, a connecting rod, and a combined system of a crankshaft and a flywheel. The transfer functions of each substructure are obtained by the reduced impedance method and so on. The transfer functions of a bearing, which is a boundary part between one substructure and another, are obtained experimentally by the harmonic exciting test. Natural frequencies, natural modes and transfer functions of the whole body are determined with the transfer functions of each substructure and bearing parts by the building block approach. The calculated results agree well with experimental ones.

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When a train is running over sharp curves, the noise is mainly caused by the flexural vibration of wheels. The noise radiating area of a spoke type wheel is smaller than that of a convensional web type wheel. Then, the spoke type wheel is supposed to reduce the noise at curves. In this paper, the characteristics of the noise radiation of the spoke type wheel is experimentally investigated, and it is found that the noise generated by the spoke type wheel is considerably smaller than that by the web type wheel. Its flexural vibration is analyzed theoretically. In this analysis, the wheel is assumed to be an annular Mindlin plate which is elastically supported by springs which simulate the spokes.

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The mechanism of specific squeal frequency was investigated by an apparatus with a steel rod and a thin steel disk. Squeals of higher modes occur in rods with smaller sectional areas and squeals of lower modes occur in large rods. Squeal is generated at specific contact positions on a rod. From the theoretical results, it was found that a squeal of the frequency near the contact frequency of the rod and disk occurs. The theoretical results on squeal frequency agree with the experimental results. Thus, squeal frequency for any contact load and position can be predicted theoretically.

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This paper deals with a theoretical research of an oil damper, whose piston is vibrating in a viscous fluid filling a fixed circular cylinder. In the previous report, transforming the annular clearance between the cylinder and the piston into a straight channel, the authors induced a drag force acting on the piston from an equation of motion of the fluid expressed in Cartesian coordinates. Therefore the result of this analysis contained an error due to the transformation. So in this report, the authors try to derive a more exact value using an equation represented in cylindrical coordinates. Comparing this solution with the former one, they proved that these are very close to each other, if there is not so much difference between the diameter of piston and the inner diameter of cylinder.

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In order to achieve energy savings, ships are now being designed with larger propellers operating at lower speed. such designs impose a heavier load on the stern tube bearing. The shaft alignment calculations have been made taking oil film characteristics of stern tube bearing into consideration. The oil film characteristics have been analyzed applying the finite width hydrodynamic theory to the curved shaft in the stern tube bearing. This theoretical analysis has made it possible to elucidate the oil film characteristics of the stern tube bearing. The optimum width-diameter ratio of stern tube bearing at lower speed has been also obtained by this analysis.

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To apply the approximate calculation formulae for tooth fillet and root stresses of a thin-rimmed gear ⁽³⁾ to the case of an internal gear, it is necessary to obtain the nominal stresses of rim. A general method to calculate the nominal stresses of rim of an internal gear has been shown for the case of an internal spur gear which is fixed or supported by different methods, e.g., for the case of bolt fixing and/or geared coupling supporting of the internal gear. The tooth fillet and root stresses obtained by this calculation method for an internal gear which is fixed bolts have shown fairly good agreement with the results of the FEM calculations and those of the stress measurements. Using this simple calculation method, influences of rim thickness and umber of teeth in the internal gear and number of fixing bolts on the stress state at fillet and root areas have been illustrated.

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In the rolling finish of gears, the tooth profile of gear is affected by the end effect at tooth tip or root. In the present study the compression test between a die roller and rectangular bars is performed at five points having different distances from the end of test piece. The range subjected to end effect is unaffected by the width of test piece. The increase of deformation due to the end effect varies almost linesrly with the increase of compressive load at every loading position but independently of the width of test piece.

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The links of planar mechanism are arranged on some parallel planes, which are called here layers, to avoid their mutual interferences. The minimum number of layers required to construct mechanisms with revolute pairs is determined from incidence matrices. All possible layer arrangements of links under the minimum number of layers are also obtained from the incidence matrices with consideration of full rotations of revolute pairs. A criterion based on layer-distances of adjacent links is proposed to select the best one out of many arrangements. Then, profiles of links are determined with aid of graphic display of relative loci of pairing points so that the links arranged on the same layers may not interfer with each other during a cycle of motion.

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In designing a bolted joint, it is important to estimate the force ratio. But this force ratio is the factor to be considered in the case where a load is applied only in the axial direction, but it is not considered when an external bending moment is applied on an assembly. In the previous paper, in the case of T-flanges, a force ratio for the external bending moment, which is the ratio of the increment of bolt axial force to the external bending moment, is introduced. In this paper, the force ratio for the external bending moment is analyzed in the case of circular flanges. The effect of the circular pitch diameter on the force ratio for the external bending moment is discussed. In addition, the stresses produced in bolts are analyzed. Then, in order to verify these analyses, experiments are carried out. Comparing these results, they are in a fairly good agreement.

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