Showing papers in "Jsme International Journal Series B-fluids and Thermal Engineering in 1964"
TL;DR: In this paper, the authors investigated the relation between the profiles of velocity and temperature of the air flowing in a vortex chamber and the dimensions of the main tube, nozzle, cold-end orifice, etc.
Abstract: In this paper, the author tried to investigate the relation between the profiles of velocity and temperature of the air flowing in a vortex chamber and the dimensions of the main tube, nozzle, cold-end orifice, etc. He obtained data for designing a standard type of vortex tube with high efficiency of energy separation. He also obtained formulae for the profiles of velocity, temperature and energy of the air flowing in a standard vortex chamber, considering the air flow in the annular region as a wall jet. Unlike the formulae represented hitherto, these formulae do not include factors such as radial velocity component or turbulent diffusivity and so may be used to predict the performance or efficiency of a standard vortex tube under any working conditions.
52 citations
TL;DR: In this paper, the effects of time and magnitude of stretching are studied experimentally and theoretically in the case of forming a sheet into cylindrical surface by stretching the sheet in circumferential direction under various conditions, and the experimental results reveal that the springback decreases with an increase of the tensile force and the amount of it is minimized when the sheet is only stretched after bending.
Abstract: In the case of forming a sheet into cylindrical surface by stretching the sheet in circumferential direction under various conditions, the effects of time and magnitude of stretching are studied experimentally and theoretically. The experimental results are well explained by the results of theoretical calculations. The obtained results reveal that the springback decreases with an increase of the tensile force, and the amount of it is minimized when the sheet is only stretched after bending. It is also found that the difference in the springback between stretching after bending and stretching with bending is small for materials having a remarkable Bauschinger effect and large for materials having little such effect. Furthermore, it is found that if it is necessary to stretch the sheet during bending, in order to decrease the springback it is desirable that the tensile force be maintained as small as possible during bending and finally a large tensile force is worked after release of the first force.
35 citations
TL;DR: In this article, the dominant factors on the generation of combustion noise are the velocity turbulences and the entropy turbulence acting as equivalent acoustic dipoles and monopoles, respectively.
Abstract: The mechanism of the generation and the characteristics of the noise associated with combustion are studied. It is shown that the dominant factors on the generation of the combustion noise are the velocity turbulences and the entropy turbulences, acting as equivalent acoustic dipoles and monopoles, respectively. Especially, concerning the diffusion flame of rich-premixed gaseous fuel, the noise in the laminar flame is mostly due to the entropy turbulences and of monopole-like characteristic, and that in the turbulent flame is mainly attributed to the velocity turbulence and of dipole-like characteristic. The noise intensities are proportional to the second and the fourth power of the mean flow velocity, respectively, and to the cubic power of the diameter of the nozzle.
20 citations
TL;DR: In this article, experiments were carried out on 11 types of straight-edged nozzles and 11 kinds of rounded-ged nozzels which have an inner diameter of about 2 mm and were used for the air-micrometer.
Abstract: Experiments were carried out on 11 types of straight-edged nozzles and 11 types of roundedged nozzles which have an inner diameter of about 2 mm These are the nozzles used for the air-micrometer, and the experiments were carried out in the case of the ratio of gap and inner diameter up to 01 using distilled water up to 3 m head and using low pressure air up to 500 mmAq differential pressure, and the discharge characteristics were investigated The results are summarized as follows : 1 Excepting the friction loss and the discharged velocity energy loss, the additional loss of head which had not been clear was determined 2 The values calculated using this result agree very well with the measured ones So, unlike the former characteristic equations, the characteristics of double-disc nozzle with a large gap can be accurately calculated, especialy when the nozzle is sharp-edged
19 citations
TL;DR: In this paper, the stresses in cemented joints, especially those by scarf and butt bondings, were studied photoelastically, and the results revealed that the stress concentrations were comparatively small on the scarf or butt bonding.
Abstract: The stresses in cemented joints, especially those by scarf and butt bondings, were studied photoelastically. The photoelastic models were made of epoxy resin and epoxy rubber, or epoxy resin and metal, namely, each material had respective elastic constant. Tests were carried out under tension and bending on a bar bonded at various angles. Some results of experiments revealed that the stress concentrations were comparatively small on the scarf or butt bonding. The other results had revealed that the stresses on bonded boundary were not uniform under tension and bending, and that in the joints with a soft adhesive layer bonded to hard adherends, the stresses concentrations were found on the end of bonded boundary with an obtuse angle, and in those with a hard adhesive layer bonded to soft adherends, found on the end of bonded boundary with an acute angle.
15 citations
TL;DR: In this paper, the thermocouple-wires were put on a spring which was fixed to the piston skirt at one end and to the crank case wall at the other end.
Abstract: The piston temperatures of two 4-stroke agricultural engines and a 2-stroke motor cycle engine were measured accurately by means of the thermocouple method, in which the thermocouple-wires were connected with the moving piston and a fixed point without any joint on the way. For this purpose we used the following two devices : (i) The thermocouple-wires were put on a spring which was fixed to the piston skirt at one end and to the crank case wall at the other end. (ii) A conduit containing the thermocouple-wires was movable with the piston through the combustion chamber. With the former device, the measurement was carried out at the speed up to 4000 rpm for a 4-stroke engine of stroke 65 mm, and with the latter, at the speed up to 8000 rpm for a 2-stroke engine of 40 mm stroke.
15 citations
TL;DR: In this article, the bending stress concentration factors of a single throw steel crank were investigated on a single-throw steel crank and the crankpin diameter was 80 mm, and the empirical formula of the stress concentration factor of crankshaft was given as follows: αk=Cf1 (ρ/d) f2 (ρd·δ/ρ·(ρ·s/d).
Abstract: The bending stress concentration factors were investigated on the single throw steel crank specimens (solid), of which crankpin diameter was 80 mm. As the result of these investigations the empirical formula of the stress concentration factor of crankshaft is given as follows : αk=Cf1 (ρ/d) f2 (ρ/d·δ/ρ·s/d) f3 (b/d) f4 (t/d) f5 (t/d·s/d) C=4.84 f1 (ρ/d)=0.420+0.160√(d/ρ-6.864) f2 (ρ/d·δ/ρ·s/d)=1+81 [0.769-(0.407-s/d)2]·δ/ρ·(ρ/d)2 f3 (b/d)=0.285 (2.2-b/d)2+0.785 f4 (t/d)=0.444 (d/t)1.4 f5 (t/d·s/d)=1-(s/d+0.1)2/(4t/d-0.7) (8gd/ρg27, 0gδ/ρg1, -0.3gs/dg0.3, 1.2gb/dg2.1, 0.36gt/dg0.56) where, αk=πd3σm/32MW, d : crankpin diameter, σm : maximum stress at crank fillet, MW : bending moment at center of web thickness, ρ : fillet radius, δ : recessed depth at fillet, b : web breadth, t : web thickness, and s=(d-dj)/2-r, dj : crankjournal diameter, r : a half stroke. The limit of uncertainty of the above formula based on 95 percent confidence limits is 6 percent, and this value is enough for practical application.
13 citations
11 citations
TL;DR: In this article, the amplitude error due to the passage was evaluated by comparing the pressure diagrams obtained by the use of a passage, with the accurate diagrams from these, it was confirmed that a diagram available for practical use was possibly obtained by raising the period of vibration twice as much as the rising time of pressure and by making the period lower than 2 to 3 degrees in crank angle.
Abstract: It is often compelled to attach an indicator passage to the pressure sensitive element in measuring the cylinder pressure of an internal combustion engine A vibration caused in the passage, however, often injures the fidelity of pressure indicated In this paper, the gas system inside the passage was firstly studied from the viewpoint of frequency-and transient-responses, and thus the relationship between the course of pressure in cylinder and the pressure indicated was derived Then the amplitude error due to the passage was evaluated by comparing the pressure diagrams obtained by the use of a passage, with the accurate diagrams From these, it was confirmed that a diagram available for practical use was possibly obtained by raising the period of vibration twice as much as the rising time of pressure and by making the period lower than 2 to 3 degrees in crank angle Further, damping effects of connecting passage were experimentally examined for improving the diagram accuracy, and an approximate formula was given to find out the optimum damping
11 citations
TL;DR: In this article, the authors studied the effect of fin pitch and height on heat transfer and pressure drop on the extended heating surfaces with transverse fin for flow direction placed in the air channel of rectangular cross section.
Abstract: The heat transfer and the pressure drop are experimentally studied on the extended heating surfaces with transverse fins for flow direction placed in the air channel of rectangular cross section. From the results of experiment on the effects of fin whose pitch and height are p and l respectively, channel height and Reynolds number, empirical equations for the heat transfer coefficient and the friction factor are presented. It has been shown that the ratio of fin pitch to fin height p/l is a most important factor for the heat transfer and pressure drop performance. In the case of the value of p/l=1.2∼1.6, the finned surface shows the most effective performance. The flow patterns between fins of the surface are observed and the effect of fin materials is also studied experimentally.
10 citations
TL;DR: In this paper, the fundamental equations of nonlinear flexural vibration for a rectangular elastic plate are solved approximately by employing a method of successive approximation, and the influences of temperature changes and large amplitudes on the period of free vibrations are established.
Abstract: The fundamental equations of nonlinear flexural vibration for a rectangular elastic plate are solved approximately by employing a method of successive approximation, and the influences of temperature changes and large amplitudes on the period of free vibrations are established. Some numerical examples are given for a plate with hinged and immovable edges, and it is shown that the above effects are considerably large and cannot be neglected even when the temperature changes are small.
TL;DR: In this paper, the Mises' yield condition was used to solve the fundamental equations corresponding to the ranges of the elasto-plastic bending and the pure elastic bending continuously.
Abstract: The elasto-plastic bending of a clamped circular plate under a partical circular uniform load is investigated by the total strain theory and the Mises'yield condition. To solve the fundamental equations corresponding to the ranges of the elasto-plastic bending and the pure elastic bending continuously, a new paramater which indicates the appearance of the plastic region on the plate is used to rewrite the fundamental equation in the pure elastic bending range. The distribution of the bending moments and the deflection in the plate, the development of the plastic region in the meridian section, the relation between the load and the mode of development of the plastic region are discussed in regard to the ratio of radii of the loading circle and the plate.
TL;DR: In this article, a theoretical analysis of heat transfer from an inclined thin flat plate by natural convection is presented, by using the same analytical method as the author did for the heat transfer of a horizontal thin flat flat plate.
Abstract: This paper deals with a theoretical analysis of heat transfer from an inclined thin flat plate by natural convection, by using same analytical method as the author did for the heat transfer from a horizontal thin flat plate. If the laminar boundary layer exists all around the plate, the local heat transfer coefficient increases at a place near the lowest point of plate, and the difference of the coefficient between the upper and lower surface decreases as the inclined angle from the horizontal plane is increased. The average heat transfer coefficient of the lower surface is larger than that of the upper surface, and the average coefficient increases as the plate approaches to the vertical position.
TL;DR: In this paper, the authors measured the temperature distribution of the piston, piston rings, cylinder wall and gas in the crank case and compared the results with Ibrahim's calculated results on the gasoline engine.
Abstract: As for as the past investigations on the heat flow from the piston are concerned, there have been few reports on the gasoline engine. So, in this report, the following are described : (1) The measurement of the temperature distributions of the pistons, piston rings, cylinder wall and gas in the crank case. (2) The measurements of the rates of heat flow from the each part of a piston at each speed of 1500, 2500 and 3500rpm, and their comparison with Ibrahim's calculated results. (3) The comparisons of piston temperatures, using various piston rings. As the result, the following were attained : (1) The rate of heat flow from the piston rings and ring lands to the cylinder wall reach as much as 81% at a speed of 3500rpm under full load. (2) The heat transfer coefficient on the back of the piston is 35∼60 kcal/m2h°C, (3) and besides the valuable data on the use of piston ring for the cooling of piston have been obtained.
TL;DR: In this paper, a number of theoretical and experimental studies on the growth and collapse of bubbles have been made in order to clarify the boiling phenomena, however, most of those studies have been conducted with heating surfaces of smaller size than bubble diameter.
Abstract: A number of theoretical and experimental studies on the growth and collapse of bubbles have been made in order to clarify the boiling phenomena. Most of those experiments, however, have been made with heating surfaces of smaller size than bubble diameter. Authors have been doubtful of the validity of applying such experimental results to boiling with a larger heating surface. In order to clarify the dependence of the bubble growth and collapse upon the shape and size of heating surface, they carried out experiments by means of the heating surfaces of horizontal circular brass plates 100 mm and 140 mm in diameter respectively and of horizontal small platinum wire 0.5 mm in diameter and found that : (1) Bubble growth and collapse are independent of heat flux. (2) Bubble collapse is strongly influenced by the degree of subcooling. (3) Bubble growth and collapse which essentially dominate the boiling heat transfer are considerably affected by the size of heating surface.
TL;DR: In this paper, a JIS orifice was fitted at the outlet of a vertical 1 inch bore pipe through which the airwater mixture flowed upward, and the pressure at a point immediately before the orifice recorded and analyzed.
Abstract: In contrast to the single-phase flow, the gas-liquid two-phase flow is generally accompanied by violent pressure fluctuations. If the fluctuation is found to follow a certain law, the law may be useful in measuring the component flow in the two-phase mixture. From this view point, the pressure fluctuation was analyzed. This paper is the first report on the result of this analysis. A JIS orifice was fitted at the outlet of a vertical 1 inch bore pipe through which the airwater mixture flowed upward. The pressure at a point immediately before the orifice was recorded and analyzed. It was found that the pressure was either larger or smaller than the time-average pressure, and never stayed at the average amount. Therefore the time rate during which the pressure was larger than the average was definitely measurable. This quantity was named the liquid-phase time ratio, and its properties were examined. If the flow rate of each component of the gas-liquid mixture was given, the new quantity was found to have a definite amount.
TL;DR: In this paper, it was shown that the micro-hardness increased rapidly at first with the increasing of test load in the small load range, then decreased gradually and became independent of the test load.
Abstract: Several experiments of micro-hardness have been performed on Al and Mg single crystal in order to clarify the effect of test conditions. The micro-hardness increased rapidly at first with the increasing of test load in the small load range, then decreased gradually and became finally independent of the test load. Such phenomena were observed in the test conditions. Firstly, it was supposed that the phenomenon of increasing micro-hardness in the small load range was caused by the external vibrations which originated from the experimental station. Secondly, it was verified that the load-dependency of micro-hardness which showed that the micro-hardness decreased with the increasing of test load was due to the heterogeneous deformation of indentation and the dissimilar indentation with respect to the indentation. So, for the micro-hardness testing it is recommended that the loading rate be kept at about 10μ/sec and the loading time of indenter kept below 10 sec.
TL;DR: In this article, the authors measured the piston temperatures of a Nissan-Automobile E-type 1200 cc gasoline engine and examined the influences of the pistion speed, load, cooling water, ignition advance, and mixture ratio upon the piston temperature.
Abstract: The piston temperatures of a Nissan-Automobile E-type 1200 cc gasoline engine were measured by the thermocouples, of which the lead-wires were passed through the combustion chamber and led to the stationary position. The influences of the pistion speed, load, cooling water, ignition advance, knocking and mixture ratio upon the piston temperature were examined. The following was worth noticing. (1) When the engine speed was 4 500 rpm under full load, the maximum temperature was about 200°C at the center of the piston head. (2) When the ignition timing was advanced, the piston temperature proportionally rose. Especially when knocking occurred, its maximum temperature reached 260°C, which was 60°C higher than that in case of the normal operation. (3) With weak mixture ratio, the temperature of exhaust gas rose, but there was little influence upon the piston temperature.
TL;DR: In this article, the experimental characteristic formulas of nozzles or orifices and double-disc Nozzles were combined for low-pressure and high-pressure air-micrometers.
Abstract: Combining the experimental characteristic formulas of nozzles or orifices and double-disc nozzles which were obtained in the last four reports, characteristic equations were worked out for the low-pressure type and high-pressure type air-micrometers. The values calculated from these characteristic equations are in good agreement with the measured ones and these equations make it possible to calculate accurately the characteristics of air-micrometer in accordance with the types of nozzle or orifice and double-disc nozzle. Using these experimental formulas, some design charts can be prepared and any desired air-micrometer can be readily designed by using these charts.
TL;DR: In this paper, the moment coefficient of a rotating disc in a closed grooved vessel with axial clearance S, pitch p and depth T of grooves has been investigated, and it was shown that axial clearances have little influence on the moment coefficients.
Abstract: Experiments on a rotating grooved disc in a closed grooved vessel were carried out with various clearances, especially very small axial clearances, and over a wider range of Reynold's numbers. From these results the effects of axial clearance S, pitch p and depth T of grooves on the moment coefficient are determined as follows : (1) When the axial clearances are very small and the surfaces are smooth, the moment coefficient Cf is proportional to R-5/6 in laminar flow region, and to R-1/4e in turbulent flow region, and independent of Re in transitional region. (2) Cf takes a minimum value at S/d≒0.0066, where d is the disc diameter, irrespective of the existence of grooves. In general, grooves have little influences on S/d. (3) Cf of a smooth or grooved disc in a grooved vessel takes a minimum value, when p/d=0.088, T/d=0.0066. The combination of a smooth disc and a grooved vessel is desirable in order to decrease Cf in laminar flow region. on the other hand, in turbulent flow region, the combination of a grooved disc and a grooved vessel is preferred.
TL;DR: In this paper, the authors made experiments on some typical hydraulic control valves, and compared the results with those of analyzing all performances of the valve to make their performances clear ; they are the performances of direct and pilot valve type relief valve, the reducing valve, and the second pressure of which is constant, the flow control valve with pressure compensator and the spool valve.
Abstract: Oil hydraulic control valves are used in an oil hydraulic system with an oil hydraulic pump or an oil hydraulic motor, etc. From the view-point of their functions they are roughly classified into three types, that is, pressure, flow and directional control. The author made experiments on some typical hydraulic control valves, and compared the results with those of analyzing all performances of the valve to make their performances clear ; they are the performances of the direct and pilot valve type relief valve, the reducing valve, the second pressure of which is constant, the flow control valve with pressure compensator and the spool valve.
TL;DR: In this article, the authors performed experimental and theoretical research on the cold-roll forming of metal strips to the cross section of circular arc through a set of the upper roll and the lower.
Abstract: The experimental and the theoretical researchs were performed on the cold-roll forming of metal strips to the cross section of circular arc through a set of the upper roll and the lower. From the experiment, it was found that the membraneous strain in the strip was negligibly small as compared with the bending strain. Therefore, the cold-roll forming was treated as a biaxial bending problem. The roll force and torque were analyzed by means of the strain energy method. The theoretical results were in good agreement with the experimental results.
TL;DR: In this paper, the size effect of fatigue strength is discussed by calculating the probability of flaws on the surface which affect the fatigue strength of materials by 1/(1+2μ) under bending and by 1/2μ under twisting.
Abstract: The relation between the twisting fatigue strength and the bending fatigue strength varies with temperatures and specimen sizes, as well as with presence of notches, flaws, and environments. In the present paper, the size effect of fatigue strength is discussed by calculating the probability of flaws on the surface which affect the fatigue strength of materials by 1/(1+2μ) under bending and by 1/(1+μ) under twisting. And fatigue tests are carried out at elevated temperatures and at a low temperature for smooth specimens and also for notched specimens under bending and twisting moments. These results and the various past experimental results are applied to the calculation of the size effect discussed above, and the following explanation is given in a unified form : the relation of size effect under bending fatigue and under twisting fatigue, the size effect of smooth specimens and notched specimens, the effect of flaws, environments, and temperatures on the fatigue strength and notch factor, and the distribution of the fatigue strengths for various sizes of specimens.
TL;DR: In this paper, the authors proposed a method by which the flatness of a surface plate can be found mechanically by measuring the spirit level of the surface plate using the two-point connecting method.
Abstract: In the case of measuring flatness of a surface plate by sensitive spirit level method, i.e., the so-called two-point connecting method, a series of level readings made in each position are connected. But their connection is generally troublesome. In this paper, the author proposes a method by which the flatness of a surface plate can be found mechanically.
TL;DR: In this article, a simple flow model was proposed, by means of which the quantities defined in the previous report were theoretically correlated, and it was proved that the actual slug flow could be fundamentally represented by the proposed flow model.
Abstract: For the two-phase slug flow in the vertical tube, a simple flow model was proposed, by means of which the quantities defined in the previous report were theoretically correlated. A series of experiments was carried out, and it was proved that the actual slug flow could be fundamentally represented by the proposed flow model. Also the two-phase discharge coefficient of the orifice was defined and experimentally correlated with the component volume flow. It was found that the component flows could be estimated by measuring the average pressure drop across the orifice and the time ratio or the void ratio.
TL;DR: In der vorliegenden Arbeit befassen sich the Verfasser mit dem Druckabfall, the Geschwindigkeit der Teilchen and der Geschindigkeitsverteilung der Forderluft in der lotrechten Rohrleitung, sowie dem Druckerfall and the Geschnitt-Gebruch in Krummer as discussed by the authors.
Abstract: In der vorliegenden Arbeit befassen sich die Verfasser mit dem Druckabfall, der Geschwindigkeit der Teilchen und der Geschwindigkeitsverteilung der Forderluft in der lotrechten Rohrleitung sowie dem Druckabfall und der Geschwindigkeit der Teilchen im Krummer. Von den Verfassern ist die empirische Formel fur den Druckabfall in der lotrechten Rohrleitung erhalten worden. Es stellte sich aus den Versuchsergebnissen heraus, daβ der Druckabfall im Krummer von der Waagerechten in die Lotrechte nach oben groβer ist als der im Krummer von der Lotrechten nach oben in die Waagerechte, und daβ die Geschwindigkeit der Teilchen in der lotrechten Rohrleitung ganz anders ist als die in der waagerechten Rohrleitung. Bei kleiner Beladung bewirken die im Gase enthaltenen Teilchen fast keinen Einfluβ auf die Geschwindigkeitsverteilung der Forderluft in der lotrechten Rohrleitung