Cylinder Body Research Articles

反応焼結法によるＮｉ基高耐食耐摩耗合金の開発

A corrosion-and wear-resistant alloy for plastic shaping machines was developed by powder metallurgy including a HIP (Hot Isostatic Pressing) process. The results were obtained as follows:(1) The composition of the new alloy was Ni-17.5 mass%Cr-24.0 Mo-3.6 B-2.9 Si-1.0 Cu. A reaction sintering method was applied to produce the new alloy. Ni-Mo-Si-Cu alloy powder and CrB powder were reaction sintered by the HIP process. CrB particles were transformed into M3B2 particles during HIP.(2) The corrosion resistance of the new alloy was 6, 45 and 100 times superior to that of centrifugal cast alloy, respectively, and almost the same as that of Hastelloy C. It was concluded that the high corrosion resistance of the new alloy was due to the addition of Cu which inhibited the preferential corrosion of the matrix by a electrochemicalcell corrosion mechanism.(3) The wear resistance of the new alloy was 3 times superior to that of centrifugal cast alloy and 150 times superior to that of Hastelloy C. This high wear resistance of the new alloy was due to fine dispersion of M3B2 particles.(4) The new alloy was reaction sintered and bonded to the inner surface of steel cylinder body. This bimetallic cylinder can be used for plastic shaping machines.

Viscous heating of a cylinder with finite length by a high viscosity fluid in steady longitudinal flow—1. Newtonian fluids

The viscous dissipation heating of a finite length cylinder exposed to a steady uniform velocity Newtonian fluid is analyzed numerically. The solution determines the elliptic, velocity and temperature field, of a high viscosity fluid about an axisymmetric cylinder. Computations are performed for different values of the Reynolds number, Prandtl number, the probe radius to length ratio and the ratio of cylinder conductivity to fluid thermal conductivity. With polymer processing in mind the Reynolds number is varied between 10 −4 and 2 × 10 −1 and the Prandtl number between 10 5 and 10 9. The results also determine the increase in the cylinder wall and tip temperature due to viscous frictional heating. Strong elliptic effects on the velocity extend over 100 radius lengths upstream from the cylinder. The velocity field results indicate a nearly ‘creeping flow’ type velocity distribution about the cylinder body. In contrast, the temperature field is confined to a very narrow region of high deformation rates around the cylinder surface.

ＨＩＰ法による粉末冶金複合製品の開発

A new method to produce bimetallic cylinders for injection molding of engineering plastics has been developed. Co based alloy was designed to improve corrosion-and wear-resistance, and fine powders having this composition were made by Ar gas atomization. Prealloyed powders were bonded to the inner surface of the cylinder body by the HIP process.Currently, these new cylinders are actually operating in the Japanese engineering plastic industry and are showing a good performance.And further, a new valve-body was produced by the same HIP process and the various properties were also discussed.

Strain Distribution and Ultimate Strength of Leg Fixing Device of Jackup Rigs

A leg fixing device, which connects together the leg and the hull of a jackup rig, is indispensable when the jackup rig develops oil and gas in harsh environment such as the North Sea, and it takes severe load through its several teeth in contact with the several teeth of the opposite leg rack. Accordingly, it is very important to know the strain distribution, deformation and ultimate strength of one pair of mutually contacting opposite teeth, and the load distribution and ultimate strength of several pairs of mutually contacting opposite teeth from the design point of view.In this paper, four kinds of scale models of leg fixing device, three were 1/4 scale (one pair of opposite teeth) and the rest 1/8 scale (six pairs of opposite teeth), were tested up to the ultimate load state, and the analysis of the models was performed by the finite element method as elasto-plastic contact problem. The results of calculations were compared with those of experiments and the following conclusions were obtained.(1) Characteristics of strain field of one pair of opposite teeth from elastic state to ultimate strength state were shown by the calculation and the calculated equivalent plastic strain distribution showed that the mechanism of failure of one pair of opposite teeth derives from shear.(2) Like the contact problem of circular cylinder and flat body, both calculations and experiments showed that the relation between load and displacement of one pair of opposite teeth was concave in elastic state and changed convex after elasto-plastic state started.(3) Both calculations and experiments confirmed that the ultimate strength of one pair of opposite teeth was obtained by the simple equation proposed in Ref. 1).(4) Simplified analysis method to estimate the load distribution of several pairs of opposite teeth was shown and found useful by the comparison between the results of calculation and experiment.(5) Concerning n pairs of opposite teeth, the calculation showed that uneven distribution of tooth load in elastic state became almost even in ultimate strength state and both the calculation and experiment showed that the ultimate strength of n pairs of opposite teeth was n times the ultimate load of one pair of opposite teeth.

Study on the vibration reduction of concrete breakers (2nd report, Vibration reduction due to the dynamic balancer driven by positive cam, and vibration isolation due to the elastic coupling between crank shaft and motor.

In the previous paper, a survey was reported on the vibrations of electrical concrete breakers, one of the typical piston-operated vibrating tools. From various analyses of vibration measurements, it was confirmed that the main cause of vibration sensitivity was the reaction force of the connecting rod via the piston, resulting from rapid air compression rather than the impingement of the chisel for the chisel holder on the front of tool. Based on such a conclusion, two kinds of system were adapted on the vibration reduction and vibration isolation of the breakers. One of them consists of the dynamic balancer driven by the positive cam, and the other consists of the elastic coupling between the crank shaft incorporated in the cylinder body and the motor section. The former was not always effective in reducing vibration in handles because of the restricted size and weight, but the latter was considerably effective in isolating vibration in handles, about 6∼10 dB smaller in vibration level than conventional ones.

Interstitial high dose-rate brachytherapy: Principle, practice and first clinical experiences with a new remote-controlled afterloading system using Ir-192

In our newly developed remote-controlled afterloading system, a single Ir-192-source is moved within hollow stainless steel needles, which are arranged strictly parallel and are uniformly spaced. Dose calculation is performed by an especially designed computer program using geometrical bodies (ellipsoid, cylinder and plane parallel body) as idealized tumor shapes. Reference points for calculation are defined on the surface of the chosen geometrical body. Theoretical base, principles of dosage, handling and first clinical experiences after treatment of 28 patients are presented.

Hydraulilc cylinder for generating vibrations

A hydraulic cylinder for generating vibrations which comprises: a cylinder body; a hollow piston rotatably mounted in said cylinder body; and a valve rotor rotatably engaged within said hollow piston, said valve rotor having a change-over valve portion adapted to be rotated for applying hydraulic loads to said piston alternately in axially opposite directions.

Numerical simulation of steady supersonic flow over spinning bodies of revolution

A recently reported parabolized Navier-Stokes code has been employed to compute the supersonic flowfield about a spinning cone and spinning and nonspinning ogive cylinder and boattailed bodies of revolution at moderate incidence. The computations were performed for flow conditions where extensive measurements for wall pressure, boundary-layer velocity profiles, and Magnus force had been obtained. Comparisons between the computational results and experiment indicate excellent agreement for angles of attack up to 6 deg. At angles greater than 6 deg discrepancies are noted which are tentatively attributed to turbulence modeling errors. The comparisons for Magnus effects show that the code accurately predicts the effects of body shape for the selected models.

Quasilinearization method for coupled dynamic problems of thermoviscoelasticity

Use of the quasilinearization method is proposed for the solution of coupled dynamic (particularly, quasistatic) problems of thermoviscoelasticity under cyclic loading. The coupled problems under consideration here include vibrations of a one-dimensional body (beam, plate, shell) and shear vibrations of a hollow cylinder made of a material with temperature-dependent properties, with the principle of temperature-time analogy applicable in the latter case. The quasilinearization method is shown to be a fast converging one when applied to the solution of these problems.

Experimental Investigation on the Boundary-Layer Flow over a Rotating Cone-Cylinder Body in a Uniform Stream

The pressure distribution and the boundary-layer flow on the surface of rotating cones or cone-cylinders having vertex angles of 15°and 30° in a uniform stream were measured, and the effects of the vertex angle, the velocity of uniform stream and the presence or lack of a cylindrical body were studied. It was concluded that the pressure on the rotating cone is not changed by the velocity of the uniform stream and the rotation, and the pressure over the rear part of cone decreases when the cylinder body is present. The relation between velocity components u and v in the boundary-layer depends upon the ratio (λ) of the circumferential velocity to the velocity of uniform stream. But the curves expressed by this relationship are similar for the same value of λ and independent of the vertex angle, the presence of lack of cylinder body, and the laminar of turbulent state. The value of λ at the transition point increases as the vertex angle and the negative pressure gradient increase.

On the Stress Distribution of Elastic Contact between Flat End of a Circular Cylinder and an Elastic Plane : 2nd Report, Non-Axisymmetrical Contact between Right Cylinder and Semi-Infinite Body by Eccentric Load

On the Stress Distribution of Elastic Contact between Flat End of a Circular Cylinder and an Elastic Plane : 2nd Report, Non-Axisymmetrical Contact between Right Cylinder and Semi-Infinite Body by Eccentric Load

An integral equation approach to heat and mass transfer problem in an infinite cylinder

In this paper the authors have developed a method of integral equations to obtain the transfer potentials for heat and mass in a body of unidimensional infinite cylinder under the influence of the most general type of boundary conditions. An approximate solution, applicable for small values of generalized time has also been worked out for the system.

Newtonian lift and drag of blunt-cone cylinder bodies.

5 Jones, R. T., Theoretical Determination of the Minimum Drag of Airfoils at Supersonic Speeds, Journal of the Aeronautical Sciences, Vol. 19, No. 12, Dec. 1952, pp. 813-822. 6 Carmichael, R. L., Castellano, C. R., and Chen, C. F., Use of Finite Element Methods for Predicting the Aerodynamics of WingBody Combinations, Analytic Methods in NASA SP 228, 1969, pp. 37-51. 7 Smith, J. H. B., Lift/Drag Ratios of Optimized Elliptic Wings at Supersonic Speeds, The Aeronautical Quarterly, Vol. XII, Aug. 1961, pp. 201-218. 8 Jones, R. T., Aerodynamic Design for Supersonic Speeds, Proceedings of the First International Congress in the Aeronautical Sciences, Advances in Aeronautical Sciences, Pergamon Press, New York, 1959, pp. 34-51. 9 Kuchemann, D., Aircraft Shapes and Their Aerodynamics, Proceedings of the 2nd I.C.A.S., Advances in Aeronautical Sciences, Vol. 34, Pergamon Press, New York, 1962, pp. 221-252. 10 Holdaway, G. H. and Hatfield, E. W., Transonic of Yawed Wings of Aspect Ratios 3 and 6 With a Sears-Haack Body and With Symmetrical and Asymmetrical Bodies Indented for a Mach Number of 1.2, RM A58C03, 1958, NACA. 11 Campbell, J. P. and Drake, H. M., Investigation of Stability and Control Characteristics of an Airplane Model With Skewed Wing in the Langley Free-Flight Tunnel, TN 1208, 1947, NACA. 12 Lee, G. H., comments appended to Kuchemann, D., Aircraft Shapes and Their Aerodynamics, Proceedings of the 2nd I.C.A.S. Advances in Aeronautical Sciences, Vol. 3-4, Pergamon Press, New York, 1962, pp. 221-252. 13 Lee, G. H., Slewed Wing Supersonics, The Aeroplane, Vol. 100, March 1961, pp. 240-241.

Aerodynamics of Finned Missiles at High Angle of Attack

A theoretical and experimental investigation of the aerodynamics of finned missiles at high angle-of-attack is presented. The interaction of the body vortex wake region with the missile fins aiid the resulting effect on the forces and moments produced by the fins is studied. An aerodynamic flow model is derived for a circular cylinder body at high angle-of-attack in subsonic or supersonic flow. The forces and moments produced by the fins in subsonic flow are calculated by utilizing the present flow model and present lifting theory. The experimental investigation consists primarily of strain gage measurements on a finned body in subsonic flow. The present aerodynamic flow model is compared with experimental crossflow data and good agreement between theory and experiment is obtained. Extensive comparison is made between the present force and moment predictions and available experimental data. Generally good agreement is obtained between theory and experiment for all of the forces and moments. Results given particular attention are nonlinear rolling phenomena, induced side force, and fin Magnus.

Stability of Finite-Difference Equation for the Transient Response of a Flat Plate

ment is obtained throughout the supersonic range of M = 1.0 to 4.0. Figure 2 shows the effect of varying the over-all fineness ratio for ogive-cylinder combinations at freestream Mach numbers from 1.5 to 3.0. The effect of ogive-to-cylinder length ratio is small as compared to the effect of the over-all fineness ratio, which affects average skin friction greatly below an over-all fineness ratio of approximately 7. Figure 3 compares the effects of various body shapes on local skin-friction coefficient, for a typical freestream Mach number of 2.0. The ogive cylinder, cone, and parabolic body of revolution show somewhat the same general skin-friction distribution along their forebodies where pressure gradients are favorable (dp/dx < 0). The effects of the adverse pressure gradients on the local skin-friction distribution are most pronounced on the parabolic body of revolution which has a rapidly increasing pressure near the aft end. This creates a rapidly falling skin-friction coefficient that approaches the point of separation. The calculation procedure appears to be capable of estimating the separation point, in the case of adverse pressure gradient, although no attempt to verify its accuracy is made.

A Dynamic Theory of Piston-Ring Lubrication : 3rd Report, Measurement of Oil Film Thickness

Some experimental studies are made on the oil film thickness of the piston-ring which was obtained theoretically in the 1 st Report. The same apparatus as in the 2 nd Report is used, and the 1 st method of this work is a measurement of the electric resistance between the cylinder and whole body of the piston-ring or its certain local parts, and the 2 nd method is a measurement of the circumferential displacement of the gap of ring. From these experiments, it is shown that the appearance of variation and the absolute value of the thickness of oil film measured against the phase of a stroke and a μU/W which is determined by the running condition coincide approximately with the result of theoretical calculation.

A Dynamic Theory of Piston-Ring Lubrication : 3rd Report, Measurement of Oil Film Thickness

Some experimental studies are made on the oil film thickness of the piston-ring which was obtained theoretically in the 1st report. The similar apparatus as in 2nd report is used, and the 1st method of this work is the measurement of the electric resistance between the cylinder and whole body of the piston-ring or its certain local parts, and the 2nd method is the measurement of the circumferential displacement of the gap of ring. From these experiments, it is shown that the appearance of variation and the absolute value of the thickness of oil film measured against the phase of a stroke and a μU/W which is determined by the running condition coincide approximately with the results of theoretical calculation.

On the Cause of Fracture of Various Bricks for Bottom Casting Pit in Teeming of Molten Steel

Studies on the main cause of fracture of various bricks for bottom casting pit and the physical-mechanical load taking place at the time of teeming of molten steel have been carried out.The distribution of internal stress in hollow circular cylinder bodies of various bricks due to the pressure of molten steel was calculated. Comparing the internal stress with the mechanical strength it was confirmed that the pressure of molten steel is not the immediate cause of the fracture of bricks. And, on the basis of above results, the economic lower limit of wall thickness of the bricks for standing the pressure of molten steel has been worked out.Then, an analysis of temperature gradient and thermal stress developing in a brick due to the rapid heating by molten steel at the time of teeming was carried out, and it was made clear that the immediate cause of fracture is the thermal stress.It was found by dimensional analysis that the factor f in the thermal stress equation is the number of dimensionless products, and that it's factor is expressed byf=c(r/K1/2⋅ρ-1/2⋅Cp-1/2) or f=c′(rh/K)a′.The effect of pyroplastic property, which fire clay bricks show at higher temperatures, on the distribution of thermal stress was estimated. And the author was able to elucidate the importance of the pyroplastic property for taking the preventive measure of the fracture of fire clay bricks.