-
Toshio YOSHINO, Toshihisa OUTSUKA
1982 Volume 25 Issue 202 Pages
485-492
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
A cross-section of the plane-woven fiber cloth reinforced plastic laminates was modelled. This model of the cross-section was composed of longitudinal glass fiber crooked thick strands and transverse strands with elliptical cross-section and matrix resin. When the model was loaded the stress state in the model was analysed with F.E.M. (finite element method) On the other hand, photoelastic specimens which had the same geometries and properties as the F.E.M. model were prepared and analysed experimentally. As a result, the cause of debonding between fiber strand and matrix resin was revealed analytically. And results of photoelastic experiments coincided qualitatively well with those of numerical computation by F.E.M. analysis.
View full abstract
-
Eiichiro TSUCHIDA, Yoshiyuki SAITO, Ichiro NAKAHARA, Masao KODAMA
1982 Volume 25 Issue 202 Pages
493-500
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
This paper presents an exact three-dimensional solution for the stresses arising in a semi-infinite elastic body having a prolate spheroidal cavity under all-round tension. The solution is based upon Boussinesq's stress function approach and is deduced by making use of the cylindrical and prolate spheroidal harmonics. The boundary conditions on the surfaces of the semi-infinite body and of the cavity are well satisfied with the aid of the relations between the cylindrical and prolate spheroidal harmonics. Numerical results are given for some different major semiaxes and shape ratios and the stress distributions around the cavity are shown graphically.
View full abstract
-
Naoki ASANO
1982 Volume 25 Issue 202 Pages
501-507
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
A finite element method applicable to an analysis of elastoimpact contact structures with a translational motion is formulated by use of the virtual work principle for two elastoimpact bodies in a contact state, which the author has presented. The method is applied to a two-dimensional behavior for longitudinal impact of two uniform rods with an equal cross section. Although the contact stresses by the method fluctuate periodically due to the lateral effect of inertia, their mean value agrees well with that by the theory of propagation of a one-dimensional elastic stress wave. Moreover we investigate the stick, slip and separate states on the impact surface between the two rods. Hence the use of the method makes it possible to calculate contact and separate states of various elastoimpact contact structures.
View full abstract
-
Takao HIGASHIMACHI, Masaru NAKAZAWA, Sueo KAWAI
1982 Volume 25 Issue 202 Pages
508-512
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
A new stress analysis program SAPRUN-2 is developed to enable analysis of the elastoplastic behavior of centrifugal compressor impellers. In this program three-dimensional curved elements are used and structural periodicity is duly considered. The stiffness matrix is stored in a one-dimensional array. This program has the practical usability from the viewpoints of solution accuracy and computation time, and gives the prediction of the critical angular velocity at the plastic collapse. The numerical results are compared with the experiment and discussed.
View full abstract
-
Tomitaro TOYOKURA, Junichi KUROKAWA, Yutaka KIMOTO
1982 Volume 25 Issue 202 Pages
513-520
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
In order to determine the flow characteristics of the laminar and the turbulent boundary layers on rotating blades of an axial-flow turbomachine, a theoretical analysis was performed taking the chord-wise pressure gradient into account with the aid of the rotating helical coordinates. Comparison of the calculated results of rotating blades with those of two-dimensional stationary ones showed that the secondary flow induced over the rotating blades has strong effect of suppressing the boundary layer growth, which results in that the transition and the separation of the boundary layer are much delayed. This effect increases with an increase of attack angle. To prove the validity of the theory, measurements were performed with an axial blower equipment. The measured results showed that the present analysis is well applicable to the estimation of the flow characteristics of the boundary layers on relatively thin and small-cambered rotating blades to the chord length.
View full abstract
-
Hisayoshi MATSUFUJI, Eiji HASEGAWA
1982 Volume 25 Issue 202 Pages
521-527
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
The process of the particle collision with a plane wall is theoretically examined in an oblique stagnation flow under the action of gravity. It is shown that a particle motion in an oblique stagnation flow can be reduced to a motion in a normal stagnation flow using a transformation. Then equations of motion in the direction perpendicular to the wall and parallel to it are independent of each other and are separately solved. The critical condition of the collision with the wall of a particle with a co-ordinate and a velocity given initially is obtained. Under the action of gravity, characteristics of the particle collision are determined depending on whether the flow of the stagnation point is normal or oblique. For several practical cases, the influence of the direction of the oblique stagnation flow and of gravity is studied, and the critical condition of a particle collision, the collision time and the position of the collision are obtained.
View full abstract
-
Tamotsu IGARASHI
1982 Volume 25 Issue 202 Pages
528-535
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
Experimental investigations were carried out on the flow characteristics around a circular cylinder with a wake splitter plate in the range of 1.3×10
4≤Re≤5.8×10
4. The gap between the cylinder and the platehaving O.29≤a/d≤1.76 long was varied. It is found that the effect of the length of the plate is divided into two types at a/d=1.O3 which have several remarkable flow patterns depending on the gap. Flow characteristics of those patterns were clarified.
View full abstract
-
Munekazu OHMI, Manabu IGUCHI, Ikuo URAHATA
1982 Volume 25 Issue 202 Pages
536-543
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
Velocity distribution and pressure gradient in an oscillating pipe flow are measured over wide ranges of Reynolds numbers and dimensionless frequencies. Wall shear stress is determined by substituting experimental values of cross-sectional mean velocity and pressure gradient into an unsteady momentum integral equation. From these experimental quantities frictional losses and four characteristic parameters describing the flow pattern are calculated. They are well represented by the known laminar theory in a laminar regime and by the turbulent quasi-steady relations in a turbulent regime. Here, turbulent quasi-steady state is defined as the state in which relationship between cross-sectional mean velocity and wall shear stress for steady turbulent pipe flow holds at any moment in a cycle.
View full abstract
-
Shinhaeng KIM
1982 Volume 25 Issue 202 Pages
544-551
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
A perturbation solution is obtained for the flow of a viscoelastic fluid through a channel whose radius varies slowly in the direction of the flow. The perturbation expansion is carried out in a small parameter used by Manton for a Newtonian flow which prescribes how slowly the radius of the channel varies. An integral rheological model with no shear thinning is used for the viscoelastic fluid. The solution is applicable to flows of low Reynolds number and low Weissenberg number. The normal and shear stresses at walls of the channel are also presented as well as the stream function. The solution is illustrated for two examples : a locally constricted channel and a converging channel, and it is generally discussed how the difference in behavior between viscoelastic and Newtonian fluids depends on the shapes of channels.
View full abstract
-
Morimatsu OHKI
1982 Volume 25 Issue 202 Pages
552-561
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
A linear theory for unsteady flow of a viscous, incompressible fluid in a semi-infinite circular tube with a porous, elastic wall is developed. The tube radially contracts or expands keeping its axial length constant. The fluid is assumed to pass through the porous wall under a certain defined condition of injection. Laminar similar solutions with respect to space and time are obtained. Velocities, pressures, frictional drags, powers and works of fluid are analyzed. A rapid contracting motion of a tube results in separating the flow into a core region and the boundary layer, while a rapid expanding motion brings about a remarkable compensating flow in the center of the tube. The conditions of elastic motions together with the conditions of injection give a classification of pumping action of a porous, elastic tube.
View full abstract
-
Morimatsu OHKI
1982 Volume 25 Issue 202 Pages
562-569
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
Linear theory for unsteady flow of a viscous, incompressible fluid through a semi-infinite circular tube with porous, elastic wall whose radius together with its length contracts or expands elastically, is considered together with the effects of injection into the wall.Laminar similar solutions with respect to space and time are obtained. Velocities, frictional drags, power and work of fluid are analyzed. There are three critical conditions of injection into the wall. The conditions of injection together with the conditions of motion of the tube either contracting or expanding, diversify the induced flow fields.
View full abstract
-
Eiji HASEGAWA, Kaoru MURATA
1982 Volume 25 Issue 202 Pages
570-575
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
Taking into account the viscosity of the fluid, the stability of a system of two different fluids being separated horizontally by a thin elastic plate in a gravitational field is studied on the basis of a linear theory. These fluids are incompressible. The plate is infinite in extent and acted on by an in-plane force. The instability considered here arises from the density difference between two fluids and the compression in the plate. In the case of a long wave, the growth rate of the disturbance depends on the density difference, not on the viscosities and the properties of the plate. In the case of a moderate wave length, the viscosities have a stabilizing effect in the sense of decreasing the growth rate, but have no influence on the critical wave number.
View full abstract
-
Koji TAKAHASHI, Tetsuhiro TSUKIJI
1982 Volume 25 Issue 202 Pages
576-582
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
This paper deals with the unsteady free jet issuing from a spoolvalve opening which varies sinusoidally. The flow pattern of the free jet is analyzed using conformal mapping, where the flow is assumed nonviscous. Experiments were conducted to visualize the flow inside the spool-valve. The theoretical results agree fairly well with the experimental ones. The following conclusions are drawn ; (a) The unsteady velocity component ν
x1 in the axial direction at infinity takes a maximum at ΩΞ2αf/ν
∞=0.3∼0.4 where a is the width of the jet at infinity, f the frequency of the valve opening and ν
∞ the steady flow velocity at infinity. (b) The increase of the clearance between the valve body and the spool land decreases ν
x1 for Ω>0.18 and increases it for Ω<0.18. (c) The phase lag of ν
x1 to the velocity U of the boundary wall increases with Ω or h/l for Ω>0.3. (d) The amplitude of the jet angle increases with the amplitude of U.
View full abstract
-
Masahide MIYAMOTO, Takanori AKIYOSHI
1982 Volume 25 Issue 202 Pages
583-590
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
Free convection heat transfer near the leading edge of semi-infinite vertical thin flat plate with uniform heat generation, has been analyzed numerically by the finite-difference method for Pr=0.72. For uniform heat flux case, the present Nusselt number distribution of free convection heat transfer is approximated well by the following equation : [numerical formula] The surface temperature distribution near the leading edge of the flat plate with uniform heat generation, which is placed vertically in air, has been calculated by considering not only free convection heat transfer but also thermal radiation and axial heat conduction in the plate. The effects of axial heat conduction in the plate on the surface temperature distribution near the leading edge are expressed in terms of the dimensionless parameter KD. The calculated temperature distributions agreed well with the experimental results using a Mach-Zehnder interferometer.
View full abstract
-
Akio SAITO, Ryusuke SHIMOMURA, Fumio KURIYAMA, Kozo KATAYAMA
1982 Volume 25 Issue 202 Pages
591-598
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
In this paper, one-dimensional transient solidification process with supercooling is discussed analytically and experimentally. Based on the results of observations, the solidification process with supercooling is classified into four processes : (a) liquid state, (b) partial-solidification state, (c) coexisting state of partial solidification and dense solidification, and (d) dense solidification state. A numerical method, which covers all the above processes, was proposed. The results of calculation by this method showed very good agreement with experimental results using pure water.
View full abstract
-
Masataka SATO
1982 Volume 25 Issue 202 Pages
599-605
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
The previous definition of negentropy by attaching the minus sign to entropy is not sufficient for the purpose of understanding such terms as information, order, non-equilibrium, and work in a unified manner. This paper proposes a new definition, a modification of the former one, which introduces a quantity which represents more adequately the above terms. This quantity, named negentropy in the system, is a function of the system. It is important to make it possible to describe the behavior of negentropy when two or more systems are involved, and mutual negentropy among systems, which is also derived from the new definition, is introduced in order to deal with such cases. Negentropy has a wide range of applicabilities in possibility. But since the close relation between negentropy and work is shown by giving the new definition, the application to the problem about the work is mainly discussed here.
View full abstract
-
Yukio SAKAI, Hiroshi TSUJI
1982 Volume 25 Issue 202 Pages
606-611
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
Experimental studies were made of NO
x formation in and its emission from a diffusion flame matrix burner, which is known as a typical shortflame burner. Profiles of temperature, stable-species and NO
x concentrations were measured in detail for methane flame at atmospheric pressure, and the process of NO
x formation and the NO
x emission characteristics were examined. Measurements were made under various conditions of the air and fuel ejection-velocities for several types of burner matrices, and the effects of these parameters on the NO
x formation in the flame zone and on the NO
x emission were investigated. Results show that the formation of NO
x is confined to a very narrow region about the flame zone and the NO
x formation and emission are controlled mainly by the air ejection velocity. The NO
x emission levels are found to be lower than those of usual combustion appliances.
View full abstract
-
Minoru TSUKAHARA, Tadashi MURAYAMA, Yasufumi YOSHIMOTO
1982 Volume 25 Issue 202 Pages
612-619
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
The authors investigated the influence of fuel properties on combustion with various emulsified fuels in a direct injection diesel engine. Results show that water-to-C heavy oil emulsion reduces NO
x, CO and smoke as water-to-gas oil and water-to-C heavy oil emulsions do. The improvement of the specific fuel consumption, however, is less remarkable than expected. This is because the effect of water vapour explosion is smaller than in the other emulsified fuels.
View full abstract
-
Kimihiko YASUDA, Nobukazu HAYASHI
1982 Volume 25 Issue 202 Pages
620-630
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
Axisymmetric subharmonic oscillations of a unifromly prestressed circular plate subjected to harmonic excitation are investigated theoretically and experimentally. In the theoretical investigation, modal equations are derived from the von Karman dynamic equations and solved by the method of averaging. The theoretical analysis reveals that subharmonic oscillations of orders 1/2 and 1/3 can occur, and that they are greatly influenced by the prestresses due to internal resonance. Experiments are conducted on a steel plate. The occurrence of the subharmonic oscillations is ascertained experimentally. The theoretical and experimental results are found to agree qualitatively.
View full abstract
-
Yoichi TATARA, Nobuyasu MORIWAKI
1982 Volume 25 Issue 202 Pages
631-637
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
Although current equations for coefficient of restitution in the central impact of solid spheres were presented only empirically as a function of the impact velocity v., theoretical equations for the coefficients of restitution as a function of v
i for the impact of spheres of equal diameter and equal material are presented in this study under the assumption that the separation of the impacting spheres is determined at the zero relative displacement. Through comparison of results measured here using two ball pendulums for spheres of brass, lead, glass, porcelain and agate, the viscous nature of the materials is estimated.
View full abstract
-
Kiyohiko UMEZAWA, Masayuki KOBAYASHI, Haruo HOUJOH
1982 Volume 25 Issue 202 Pages
638-645
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
To study acoustic transmission path from the inside to the outside of rectangular enclosures, a simple gear box model made of 1.1mm, 2.3mm and 9.0mm steel plates, has been examined by means of acoustical holography. The behavior of sound radiation depends on the relation between the bending wave length in plate (λ
pl) and the sound wave length in air (λ
air). The high frequency sound (λ
pl/λ
ajr>1.5) is radiated from all over the plate according to its resonant mode. However, the sound in the lower frequency range (λ
pl/λ
air>1.5) is apparently radiated only from the edges with less power than that of the former condition. This is attributed to the radiation in the tangential directions of side plates. The result would be applicable to designing a gear system for noise attenuation.
View full abstract
-
Ken IKEUCHI, Haruo MORI, Toshihumi OKUBO, Shuzo ICHI
1982 Volume 25 Issue 202 Pages
646-652
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
In this paper, circular squeeze films between a rigid plane and an elastomer attached on a rigid base or a thin circular plate under periodic motion are analyzed, and the film thickness, the film pressure, the load capacity and the absorbed power are calculated. In the experiment, thrust bearings with two kinds of compliant surfaces are vibrated and the floating height and the film pressure are measured to confirm the theory. The principal conclusions reached are ; (1) A periodic circular squeeze film has load carrying capacity and cavitation is prevented by inward pumping. (2) The power absorbability of an elastomer as a damper takes maximum value with load. (3) The theoretical power absorbability of a thin circular plate increases with load, and actually it is limited by cavitation.
View full abstract
-
Hiromu HASHIMOTO, Sanae WADA
1982 Volume 25 Issue 202 Pages
653-662
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
It is a purpose of this paper to discuss both turbulence and inertia effects on the static and dynamic characteristics of high speed journal bearings. Because of the difficulty of analysis, infinitely long and short width bearings are dealt with analytically instead of finite width bearings. It is found that the static characteristics such as the Sommerfeld number and the locus of shaft center are affected mainly by turbulence but the dynamic ones such as the spring, damping and acceleration coefficients of lubricant film and the stability of rotors are affected by inertia.
View full abstract
-
Yutaka MIYAKE, Nobuyoshi KAWABATA, Akira T0MINAGA, Susumu MURATA
1982 Volume 25 Issue 202 Pages
663-670
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
A two-dimensional analysis is presented for the dynamic performance of spiral groove spherical thrust bearings. The analysis is carried out to obtain the dynamic stiffness and damping factor for the case of vertical and translatory oscillations and the reaction forces of the film in the case of whirl motion. The analysis is restricted to the case where the centers of the rotating and stationary spheres coincide. New equations based on the narrow groove hypothesis are derived and numerical examples are presented. The results are compared with those of the two-dimensional analysis to demonstrate the accuracy.
View full abstract
-
Toshimi TOBE, Noboru MARUYAMA
1982 Volume 25 Issue 202 Pages
671-678
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
Bending fatigue tests of spur gear teeth made of normalized O.45% carbon steel (JIS S45C) are performed and several cumulative damage rules are examined taking account of the scatter of fatigue strength. The effect of the pattern of time variation of the tooth fillet stress is also investigated. Program loading tests with variation coefficients 1/12 and 1/9 indicate that Miner's rule is adaptable in time endurance region. The effect of the pattern of fillet stress on fatigue damage is observed in time endurance region, which cannot be explained by the count method such as peak method and full wave method.
View full abstract
-
Tae-Hyong CHONG, Toshiyuki SUZUKI, Toshio AIDA, Hiroshige FUJIO
1982 Volume 25 Issue 202 Pages
679-686
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
The influences of rim thickness of an internal spur gear on tensile and compressive bending stresses at tooth fillets and bottoms are discussed. The stress measurements by strain gages, the photoelasticity experiments, and stress analyses by use of the finite element method showed that the position where the maximum stress appears in an internal gear is different from that of an external gear. Especially when the rim thickness of an internal gear is thin, the maximum tensile stress appears at the center of the bottom of the tooth space, which is apart from the loaded tooth. As the rim thickness becomes thinner, the maximum compressive stress at the fillet of the loaded tooth increases sharply, while the maximum tensile stress hardly changes. As meshing proceeds, the tooth fillet and bottom stresses of a thin-rimmed internal gear alternate more strongly than those of a solid or thicker rimmed gear.
View full abstract
-
Yoshio TERAUCHI, Kazuteru NAGAMURA, Hiromitsu SAIJO
1982 Volume 25 Issue 202 Pages
687-695
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
In a previous paper, the authors have already reported on the design of an involute-cycloid composite tooth profile gear having larger bending and contact strengths than the involute gear. In the present paper, the surface durability of the involute-cycloid composite tooth profile gear is investigated by carrying out a pitting test, and the experimental result explaines the growth of a pitting of this gear. Furthermore, the superiority of the surface durability of the involute-cycloid composite tooth profile gear is confirmed experimentally, compared with the durability of the involute gear measured at the same time.
View full abstract
-
Muneharu SAIGO, Tsuneji YADA
1982 Volume 25 Issue 202 Pages
696-703
Published: 1982
Released on J-STAGE: February 15, 2008
JOURNAL
FREE ACCESS
This paper deals with the theoretical analysis and experimental results concerning to a tentatively designed variable transmission for the flywheel vehicles. This transmission is constructed of two devices. One is a 2-degrees-of-freedom epicyclic gear system including planet gear with unbalance mass and the other is a torque rectifier system consisting of two sets of one-way clutches. While this epicyclic gear is running, an alternating torque is generated. The rectifier system rectifies the alternative torque to a directional one. The authors analyzed the velocity change process of two flywheels connected by this transmission and conducted numerical simulation of this process. The authors also made an experiment of this system and compared the results with the simulation ones. Both results have shown good agreement.
View full abstract
