The problems of the interference of notch and loaded ends which must be considered especially in the material test are discussed quantitatively. For this purpose, in the 2nd report, the cases of a circular cylinder having semicircular groove under several tensile load conditions on its partial surfaces, with the positions varied, are taken up. For the analysis, the point matching method is adopted to obtain the stress field superposed two solutions for each cylinder loaded on its partial surfaces. Furthermore, by the same method of solution, the problems of stress concentration due to circular groove are treated.

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There are two points to which special attention should be paid in the design of flanges ; the failure of the flange due to high stresses and the leakage of inner fluid through the gasket seat. The formulas for calculating flange stresses given in the conventional Standards are so approximate as to require further investigation. In this report, the stress distributions in a standard integral flange are analyzed by Finite Element Method, and the effects of the design factors (especially fillet radius and hub taper) on the stress concentration at the fillet are clarified. Then, the stress values obtained by Finite Element Method are compared with the values obtained by ASME and JIS Standards, and it is found that the maximum meridional stress is about one and a half times larger than the maximum stress obtained by ASME or JIS Standard.

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The leakage of inner fluid through the gasket seat is influenced by the gasket material, inner fluid, the fastened force of the bolts, etc. Especially, the pressure distribution on the gasket seat is considered the most important factor for the leakage. In this report, the effective seating width of the gasket was analyzed by FEM and was compared with the values given in JIS and ASME Standards. Moreover, the minimum number of bolts required to get almost uniform pressure on the gasket seat was determined. The effect of the number of bolts on the flange stress was also analyzed and discussed.

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This paper gives a three-dimensional solution for the stresses and displacements around an elastic spherical inclusion perfectly bonded to an infinite circular cylinder, when the cylinder is under transverse bending. The analysis is based upon Dougall's stress function approach referred to the cylindrical and spherical harmonics. The boundary conditions on the surface of the cylinder and the contact surface are well satisfied by using the relations between the cylindrical and spherical functions. Numerical results are given for various rations of the elastic moduli of the inclusion and the cylinder and four different radii of the inclusion.

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Presented in this paper are the results of an experimental investigation of a two-dimensional turbulent boundary layer disturbed by a rectangular cylinder attached to a smooth plane wall with the axis normal to the direction of the main flow. Turbulent energy, turbulent shear stress, probability density of fluctuating velocities, spectra of stream-wise turbulent energy, intermittecy factor, correlation function and integral scales of turbulent eddies are measured in detail with constant-temperature hot-wise anemometers. The main features of the disturbed turbulent boundary layers are also discussed in comparison with those of equilibrium turbulent boundary layers.

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The present work is done to explain the characteristics of a flow field affected by an interference between a nonuniform cross flow and unheated jets issued from a single circular orifice or a single row of equally spaced circular orifices on a flat floor. Data from measurements of the total pressure and the flow direction and those from flow visualization experiments are presented for a low velocity ratio of 2. In the jet region downstream of a point, at which the minimum jet spread appears in the plane of symmetry of jets, there are large differences between characteristics of a single jet and a component jet of a multiple jet. The floor boundary layer downstream of jet orifices is affected greatly by a circulating flow, which is a vortexlike flow induced within the cross flow. The origin of the circulating flow also is discussed. The mutual interference between component jets of the multiple jet has a great influence on their spreads.

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In a volute pump the periodic fluctuation of the velocity and the pressure behind the impeller are one of the major sources of vibration and noise of blade passing frequency. Therefore knowledge on the fluctuating flow behind the impeller is important for the noise reduction of pump. Experimental investigation was performed to detect the flow behind the impeller. Velocity fluctuations are much affected by the viscous wakes and the effects of the viscous wakes increase with a decreasing flow coefficient. Static pressure fluctuations are less affected by viscous wakes and they show good agreement with the predictions by the potential flow theory. Behaviors of the fundamental and harmonics of the fluctuations are also described.

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An experimental investigation has been made on the structure of fluctuations of short duration time-mean-velocity, which are primarily due to fluctuations of the turbulent boundary layer thickness, and their effects on the fine structure of turbulence in the entrance region of a pipe. Both the shape of spectrum and the dominating frequency range of mean velocity fluctuations differ markedly from those of the relevant turbulence-velocity component. A slow variation of mean velocity with time induces a similar variation of turbulence intensity over the entire portion of the boundary layer. In the inner layer, the "production effect" caused by mean velocity fluctuations changes the structure of turbulence, while in the outer layer the "convection effect" induced by mean velocity fluctuations governs the overall characteristics of turbulent velocity field.

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The purpose of this is to make clear the flow instability problem in two-phase flow systems. In this first report, an experimental study was conducted on the oscillatory flow instabilities in an airwater two-phase flow system with upstream compressible volume. The flow pattern during the oscillation and the effects of the compressible volume and the average superficial velocity on the limit cycles were investigated. The periods of the oscillations were well correlated by two characteristic parameters obtained from a simple non-linear analysis.

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This paper presents the performance characteristics of gas turbine cycles with supercritical back-pressure and several condensation cycles, using carbon dioxide as a working fluid. They are computed from the data on the thermodynamic properties of CO₂. As a result, it is shown that thermal efficiency in CO₂ cycles increases at the rate of ( 3 4 ) % in proportion to a turbine inlet temperature rise of 100 °C and is little affected by turbine inlet temperature rise of 100°C and is little affected by turbine inlet pressure higher than 200 ata. Also, thermal efficiency of CO₂ gas turbine cycle with supercritical back-pressure is lower by ( 6 9 ) % than that of CO₂ condensation cycles. Some CO₂ condensation cycles exhibit a better performance than the conventional steam power-plant cycles at a turbine inlet pressure of about 250 ata and turbine inlet temperatures higher than 600 °C.

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Further improvements in thermal efficiency of steam and nuclear power plants are an important problem in the present energy crisis. Following the 1st and 2nd reports⁽¹⁾⁽²⁾, this paper presents a performance analysis of condensation cycles using carbon dioxide as a working fluid. The approximate equations of sufficient accuracy are derived for the enthalpy, the entropy, the mechanical works and cold end (minimum) enthalpy difference in regenerators in order to analyze CO₂ cycle performance. By utilizing these approximate equations, the performance characteristics of CO₂ condensation cycles with non-regenerator, 1-regenerator and 2-regenerator, and values of optimum reheat pressures have been analyzed and discussed. As a result, the effects of cycle parameters on the cycle performance can be expressed by an equation. This method makes it easier to understand the effect of each parameter on the CO₂ cycle performance owing to the expression by analytical equations than the direct calculation method from the data on the thermodynamic properties.

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Temperature distribution and thermal correlation of piston rings and piston in high speed diesel engines under actual operating conditions, in spite of their importance, have not been clarified due to the difficulties involved in the measurement. Authors overcame the difficulties and the temperatures were measured directly and precisely by means of thermocouples. As the result, concerning the heat flow pattern and the flow rate, interesting differences among the top, the second and the oil rings, and also between the plain and the taper faced ring were revealed. In addition, the amount of heat transferred to the piston, and the parcentage of each heat released from the piston to other parts were determined.

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The analysis of a gas exchange process by computer simulations of an engine cycle shows that the total amount of heat transferred from a cylinder wall during the intake process is related to the product of volumetric efficiency and an average gas temperature in an inlet port, independent of the heat transferred in the exhaust process. An average heat transfer coefficient in an intake process is obtained on this principle, heat transfer coefficient in an intake process is obtained on principle. based on the result that the calculated volumetric efficiency agrees very well with the experimental value under the condition that the heat transfer is negligible. An average heat transfer coefficient in the exhaust process obtained from an average exhaust gas temperature is less than that in the intake process over most of the engine speed range tested.

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It is well known that diesel knock intensity can be reduced by appropriate double injection. The authors have made an optical and theoretical investigation of the combustion mechanism of the pilot fuel. It is known that the pilot fuel burns with a different mechanism corresponding to the injection timing. In the case of retarded pilot injection, e. g., 30°BTDC or later, the ignited mixture initially burns rapidly with intense luminosity under near-stoichiometric conditions. However, the amount of fuel is so small that pressure rise is not sufficient to cause diesel knock. When the pilot injection timing is earlier, weak luminosity is observed because of the relatively weak mixture and low burning velocity, but the flame has enough energy to ignite the main fuel. When the pilot fuel is injected at the scavenging top dead center, intermediate products which show no luminosity shorten the ignition lag of the main fuel.

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This paper presents some results or the experimental investigation on the effect of initial temperature on the diesel combustion processes carried out in a constant volume combustion chamber. The flollowing conclusions can be drawn from the experiments : (1)The initial temperature has an influence on ignition delay, illumination delay, pressure rise delay, first flame formation, brightness of flame and rate heat release. (2)As the initial temperature decreases, the flame formation can be observed as dark luminous dots and a unique combustion like twinkling stars can be found. (3)The empirical relationship between illumination delay τ_i and ignition delay τ_id, and initial pressure p₀, initial temperature T₀ and oxygen concentration φ can be presented by the following forms : τ_i, τ_ed ∝ p₀ ⁿφ^cexp(B/T₀) .

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The continuous mass distribution of an overhanging coupler in a four-bar linkage is replaced by a lumped mass model, and the ordinary differential equations of motion for transverse vibration of the coupler are derived employing finite difference approximations. Comparison shows very good agreement between the numerical solutions of the these equations and the experimental results for the coupler with an overhanging end at crank side in a crank-lever mechanism. According to the numerical and experimental examination, the overhanging coupler is greatly influenced by the mass of overhanging portion and there is a suitable range of the masses to decrease the bending deflection and strain due to transverse vibration of the coupler.

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The static characteristics of outwardly pumping spherical spiral groove bearings are investigated. Solving the differential equation for a bearing which has an infinite number of grooves, we obtain the axial load capacity and the total liquid flow under radially concentric operating conditions. The effects of the bearing parameters on the load capacity and the liquid flow are examined. The experimental results are in good agreement with the theoretical ones. Although the axial load capacity of an outwardly pumping spherical spiral groove bearing is a fraction of that of an inwardly pumping one, and outwardly pumping spherical spiral groove bearing has enough load capacity.

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It has been already pointed out and investigated in the studies of dynamic behavior of gear system that the distinctive phenomena such as jump phenomena or subharmonic oscillation, which are peculiar to nonlinear systems, occur. These phenomena are considered to be caused mainly by the backlash of gear pair. In this paper, the relation between the phenomena and the gear system parameters and the geometrical behavior of the phenomena on the phase plane, which have been little discussed in the past, are investigated by applying the method of harmonic balance and the transformation theory.

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A finite element technique was used to obtain two-demensional stress distributions in gear tooth fillets. In this study we have treated the case of a crack type flaw existing normal to the free surface at the most critically stressed point in the tensile fillet. The Mode I and Mode II stress intensity factors were computed for the leading edges of hypothetical cracks by using finite element techniques. The results show that stress intensity factors for the opening fracture mode are significantly greater than those for the edge sliding mode for all cases investigated. The computed stress intensity factors were utilized for the following purposes : 1. a simulation of crack propagation in the tensile fillet, 2. a computation of the allowable load for a gear having a crack in the tensile fillet, and 3. a computation, for a given load condition, of the residual life of a gear having a crack in the tensile fillet.

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