bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Various Grinding Conditions Upon Residual Stresses in Titanium
Authors: Clorite P. A. , Reed E. C. 
Published: January 2022

Abstract
Grinding conditions may be expected to affect residual surface stresses from any particular grinding operation. Stresses were measured in titanium test bars, surface-ground with various wheels, speeds, grinding fluids, down-feeds, and crossfeeds. Results suggest that, with suitable precautions, titanium alloys may be ground under either “near-normal” or “low-speed” conditions with acceptable grinding ratios and with low residual stresses.
Measurements of the Total Absorptivity for Solar Radiation of Several Engineering Materials
Authors: Birkebak Richard C. , Hartnett J. P. 
Published: January 2022

Abstract
Values are presented of the total solar absorptivity of several porous materials presently being considered for transpiration cooling of high-speed vehicles. To specify these surfaces photomicrographs and a chemical analysis are presented. Two schemes used in the measurement of the absorptivity values are described in the text, a comparison technique and an integrating radiometer method.
Algebraic Approach to Design of Automatic Controls
Authors: Oldenburger Rufus 
Published: January 2022

Abstract
The solution of linear problems in automatic control is generally reduced to the study of ordinary differential equations and thus to characteristic equations, which are algebraic. It is then necessary to solve an algebraic equation to predict the transients for a given controlled system. Whether or not the system is stable can be determined from the simple test of Routh. Because of the great difficulties encountered in the past in solving algebraic equations, especially in the case of all roots complex, resort has been made to qualitative methods of automatic control design based on frequency response and other techniques. The author applies to algebraic equations for stable systems certain procedures, including a right to left synthetic division, which enable the engineer to approximate some of the roots, after which the solution for all of the roots can be obtained readily. From the roots, the analyst can tell what the transients will look like. Good transients are necessary for good control. The author’s method, in use at the Woodward Governor Company for several years, is applied to the design of a governor for a gas turbine.
Statistical Treatment of Sampled-Data Control Systems for Actual Random Inputs
Authors: Mori Masahiro 
Published: January 2022

Abstract
Fundamental statistical relations of sampled-data systems in terms of the correlation functions of time series, the pulse spectral densities, and the modified z-transform are presented. If one is interested in signals between sampling instants, the modified z-transform method can be applied easily to the statistical treatments, as are presented in the paper. The relation between this method and the analysis on the basis of variable-system theory is proved. Examples are given discussing discrete compensation of sampled-data control system from the statistical standpoint.
The Time and Temperature Dependence of Thermal Stresses in Cylindrical Reactor Fuel Elements
Authors: Merckx K. R. 
Published: January 2022

Abstract
A method of calculating the thermal stresses in cylindrical shapes is developed in this paper which uses a material model relating strain rate, temperature, strain, and stress. The material model, evaluated for unirradiated uranium, is used with this method to obtain the build-up and decay of the thermal stresses and strains in a solid-uranium fuel element operating in the temperature ranges of 100 to 350 C and 350 to 600 C during a 25-min period of increasing power generation and 700-min period of steady-state operation. During the period of increasing power generation, the elastic surface stresses are predicted to relax 60 per cent for the 100–350 C example and 48 per cent for the 350–600 C example. Further relaxation of 11.5 per cent for the 100–350 C case and 40 per cent for the 350–600 C case is calculated during the period of steady-state power generation.
Shear-Zone Temperature in Metal Cutting and Its Effects on Shear-Flow Stress
Authors: Kececioglu Dimitri 
Published: January 2022

Abstract
Relationships are given from which the mean shear-zone temperature in oblique, as well as in orthogonal cutting, can be calculated. The mean shear-zone temperature, developed when machining SAE 1015, 118 Bhn seamless-steel tubing under a wide range of cutting conditions, is calculated and is found to vary from about 410 to 840 F. The effect of the mean shear-zone temperature on the mean shear-flow stress is studied. In general, the mean shear-flow stress is found to decrease by about 1800 psi for a 100-deg F increase in the mean shear-zone temperature within the range of 410 and 840 F. This compares with the little or no effect of the mean shear-zone temperature on the mean shear-flow stress reported by Shaw and Finnie (1) and Chao and Bisacre (2), respectively. A more comprehensive approach is proposed to establish the effect of the important shear-zone factors on the mean shear-flow stress.
Heat Transfer in Liquid Metals
Authors: Lykoudis P. S. , Touloukian Y. S. 
Published: January 2022

Abstract
The problem of heat transfer in liquid metals is studied for the case of a fully developed turbulent flow in cylindrical pipes of constant diameter, the fluid under consideration being heated (or cooled) by a constant and uniform heat input at the wall. In the analysis, the similarity theory between heat and momentum transfer is used. A theory is presented which gives the ratio of eddy diffusivities for heat and momentum transfer as a function of the Prandtl modulus. It is shown that heat transfer in liquid metals can be analyzed universally in terms of a dimensionless parameter called the “generalized Peclet modulus” and defined by the relationNPe​*=(NRe​*)(NPr​*)=[NRe(f/2)1/2](NPrσ) Temperature profiles are presented and the limiting cases for NPr = 0 are studied.
On the Stability of Boiling Heat Transfer
Authors: Zuber Novak 
Published: January 2022

Abstract
Boiling heat transfer in the nucleate region is reviewed. The transition film-boiling region is analyzed by considering the stability of a plane vortex sheet separating two inviscid fluids. Using the classical results of Helmholtz, Kelvin, and Rayleigh, expressions have been derived that predict the maximum and minimum heat-transfer rates in the nucleate and the film-boiling regimes, respectively. The model exhibits the essential features of the phenomenon and shows good agreement with experimental data.
Combined Free and Forced Convection in a Constant-Temperature Vertical Tube
Authors: Jackson T. W. , Harrison W. B. , Boteler W. C. 
Published: January 2022

Abstract
An experimental study of superposed free and forced convection for air in a vertical tube is examined. The Nusselt modulus, based on the log-mean-temperature difference, ranged from 15.0 to 57.1; the Graetz modulus, based on the bulk or average temperature of the air, ranged from 40.2 to 1710; and the Grashof-Prandtl D/L modulus, based on properties of air at the wall temperature, ranged from 1.05 × 105 to 1.30 × 106. The Martinelli equation for heating fluids flowing vertically upward does not correlate the data satisfactorily. An analysis of the system from a macroscopic viewpoint leads to the derivation of an equation which fits the experimental data.
Theoretical and Experimental Analysis of Hydrodynamic Gas-Lubricated Journal Bearings
Authors: Sternlicht B. , Elwell R. C. 
Published: January 2022

Abstract
In recent years, gas-lubricated bearings have aroused a great amount of interest. The interest is centered on the advantages of gas bearings for four major applications: (a) High-temperature devices, for which there is yet no lubricant available. (b) Radioactive atmospheres, where conventional lubricants may break down. (c) Applications sensitive to contamination, such as jet engines, where fouling from lubricating oil becomes serious. (d) Low-friction devices—an especially important advantage because of the trend to high-speed machinery.
This paper presents a numerical solution for finite-width journal bearings and results of experiments conducted with air-lubricated hydrodynamic journal bearings. Comparison is made between theoretical and experimental results. Design formulas and recommendations for future studies also are included.
Laminar Film Condensation of Pure Saturated Vapors on Inclined Circular Cylinders
Authors: Hassan Kamal-Eldin , Jakob Max 
Published: January 2022

Abstract
Laminar film condensation of pure saturated vapors on inclined circular cylinders is treated analytically. The analysis is based on, and made under the same assumptions of, Nusselt’s theory of film condensation. Experiments were performed to check the analytic results.
In the analysis, the problem is expressed in terms of dimensionless groups and the solution gives, in these terms, the local film thickness at any point on the surface of a cylinder. From the results of the analysis one can obtain the local film coefficient, and hence a mean film coefficient for the entire surface of any cylinder at any inclination.
The analysis shows that every tube has an optimum inclination at which the rate of condensation on the entire tube is a maximum.
The experiments were carried out by condensing steam on the inside surface of a thick copper tube 1¼ in. diam and about 8⅛ in. long. The actual film coefficients obtained during the experiments were 28 to 100 per cent higher than those predicted by the theoretical analysis. The deviation from the theory increased with the inclination of the tube and the temperature difference between the tube surface and the steam.
The Third Law of Thermodynamics: A Half-Century Appraisal of the Nernst Heat Theorem
Authors: Potter J. H. 
Published: January 2022

Abstract
Fifty years have passed since Nernst formulated his “New Heat Theorem,” which he subsequently referred to as the “Third Law of Thermodynamics.” The several statements of the theorem are examined in the light of classical thermodynamics, quantum considerations, and recent low-temperature experiments. The limitations under which the heat theorem may be considered a basic scientific law are cited.
The Effect of Tool-Chip Contact Area in Metal Machining
Authors: Takeyama H. , Usui E. 
Published: January 2022

Abstract
This paper stresses the effect of the tool-chip contact area in metal machining. Little attention has been paid to this variable in analyzing machinability. According to authors’ tests, the tool-chip contact area is closely related not only with the machining performance, but with the tool life. This paper treats the former subject summing up the results obtained by the experiments using special devices.
Influence of Pressure and Temperature on Oil Viscosity in Thrust Bearings
Authors: Sternlicht B. 
Published: January 2022

Abstract
A theoretical study to determine the influence of pressure and temperature on oil viscosity in finite-length thrust bearings. This paper points out that it is theoretically possible to determine the influence that pressure and temperature play on oil viscosity and, in turn, on bearing performance by solving the energy and Reynolds equations simultaneously.
Symposium on Welded Spiral Cases from the Consulting Engineers’ and Users’ Viewpoint: Welded Spiral Case Construction Procedures
Authors: Latham G. R. 
Published: January 2022

Abstract
This paper discusses comparative costs between riveted and welded spiral cases, suggests specific requirements for insuring satisfactory welded spiral cases, under varying erection conditions, and sets forth construction and welding procedures being carried out on three different examples.
The Transient Response of a Two-Fluid Counterflow Heat Exchanger—The Gas-Turbine Regenerator
Authors: Cima R. M. , London A. L. 
Published: January 2022

Abstract
Presented are some solutions for the transient behavior of a two-fluid direct-transfer counterflow gas-turbine regenerator, obtained experimentally using an electrical analog system. While restrictions were imposed on certain parameters with the gas-turbine-regenerator problem in mind, these results, presented in nondimensional form, are also of limited use for other two-fluid exchanger problems. A set of seven independent nondimensional parameters is proposed for general use. These include the three commonly associated with the steady-state performance plus four additional parameters unique to the transient problem. The electrical analog system is described in the Appendix and the associated experimental uncertainties are considered.
Sulfuric Acid Corrosion in Oil-Fired Boilers—Studies on Sulfur Trioxide Formation
Authors: Anderson Donald R. , Manlik Frank P. 
Published: January 2022

Abstract
Experimental studies on economizer and air-heater corrosion resulting from the formation of sulfuric acid in residual-oil-fired boilers are described. Factors controlling the oxidation of sulfur dioxide to sulfur trioxide have been investigated in a small experimental boiler. The fuel used was a distillate oil to which synthetic compounds were added to simulate the sulfur and metallic components commonly found in residual oils. The sulfur trioxide content of the flue gases was determined indirectly by measuring the corrosion of and sulfate deposition on a steel specimen maintained at a controlled temperature.
In an initially clean boiler, approximately equal quantities of sulfur trioxide formed in the flame, furnace, and convection sections, while less formed in the economizer-air heater section. Nickel, iron, sodium, and vanadium in the fuel each decreased the corrosion normally experienced by the test specimen, the magnitude of the effect increasing in the order given. Deposits of these metallic fuel-ash components in the boiler had a relatively small effect on the corrosion of the test specimen. Only the iron deposits indicated significant catalytic activity for the oxidation of sulfur dioxide to sulfur trioxide.
Combinations of sodium and vanadium in the fuel were found to decrease corrosion in an initially clean furnace, but boiler deposits from certain combinations of these elements were found to increase corrosion substantially. This catalytic effect is predominant over extended periods of time.
An Investigation of the Variation in Heat Absorption in a Pulverized-Coal-Fired Slag-Tap Steam Boiler at Blaine Island, Charleston, W. Va.
Authors: Orning A. A. , Weintraub M. , Schwartz C. H. , Mihok E. A. , McCann C. R. , Harrold W. C. 
Published: January 2022

Abstract
This paper resulted from the sixth in a series of investigations of heat absorption in large steam-boiler furnaces, sponsored by The American Society of Mechanical Engineers Special Research Committee on Furnace Performance Factors. The furnace heat absorption was determined from the furnace exit-gas composition and temperature in 18 tests on a steam generator rated at 250,000 lb of steam per hr at 675 psi and 670 F. The furnace was fired with pulverized coal, through opposed burners with reinjection of fly ash, over a refractory-insulated slagging bottom. Furnace heat absorption, at various loads and excess air values, was correlated with the adiabatic flame temperature and the residence time of combustion products in the furnace. The furnace performance was found to depend upon burner adjustments, but did not significantly depend upon recirculation of fly ash.
Effects of Stage Characteristics and Matching on Axial-Flow-Compressor Performance
Authors: Stone Aubrey 
Published: January 2022

Abstract
The use of stage characteristics obtained from test data in the performance analysis and development of an axial-flow compressor is described. The discussion is illustrated by an analysis of the general trends in relative stage matching as shown by an idealized example and also by test experience. Factors governing major performance parameters are discussed and certain development problems and possible solutions are reviewed.
Application of the Analog Computer to Product Dynamic Performance in Typical Hydraulic Circuits
Authors: Reethof Gerhard 
Published: January 2022

Abstract
The successful use of electronic-analog-computing techniques in the simulation of typical hydraulic systems is demonstrated. As an example, the instabilities of a certain open-center hydraulic-booster system are simulated, and corrective action is indicated and verified. The study involves the analysis of a grossly nonlinear system and methods of function generation are given.
Thermal Transfer in Turbulent Gas Streams—Effect of Turbulence on Macroscopic Transport From Spheres
Authors: Sato Kazuhiko , Sage B. H. 
Published: January 2022

Abstract
The rate of thermal transport from spheres in a flowing stream is of interest in many industrial operations. Limited data are available concerning the effect of turbulence level on this transfer process. Measurements of the thermal transport from spheres to an air stream at four levels of turbulence were made at four velocities varying between 4 and 32 fps. Results are presented in terms of the Nusselt number. The experimental work is a portion of a detailed study of the local thermal and material transport from spheres in turbulent air streams. The data indicate a significant increase in the thermal transport with an increase in the level of turbulence at a constant Reynolds number. For example, the Nusselt number was increased from 53 to 62 upon an increase in the level of turbulence from 0.05 to 0.12 at a Reynolds number of 7200.
Effect of Vibration on Heat Transfer From a Wire to Air in Parallel Flow
Authors: Anantanarayanan R. , Ramachandran A. 
Published: January 2022

Abstract
Studies on the effect of vibration of the heat-transferring surface on convective heat transfer are few and limited to natural-convection conditions. The present investigation deals with the influence of vibration on heat transfer from an electrically heated nichrome wire to parallel air streams. Air velocities ranged from 34 to 63 fps. At each air velocity, frequencies ranging from 75 to 120 cycles per second and different amplitudes were employed as vibrational variables. Both frequency and amplitude increased the heat-transfer coefficient. An increase as high as 130 per cent was obtained. The correlation of the experimental data shows that the proportional increase in heat transfer was controlled by the ratio of the mean vibrational velocity to the air-stream velocity.
Local Laminar Heat Transfer in Wedge-Shaped Passages
Authors: Eckert E. R. G. , Irvine T. F. , Yen J. T. 
Published: January 2022

Abstract
Heat transfer in noncircular passages recently has received increased attention in connection with various engineering applications, especially with nuclear-reactor technology. The present paper presents the results of calculations for heat transfer connected with steady laminar flow through ducts whose cross sections have the shape of circular sectors. Hydraulically and thermally developed flow is assumed. The temperature field, peripheral distribution of inner-duct surface temperature and of heat flux, as well as heat-transfer coefficients and friction factors, are presented for two boundary conditions: Peripherally constant heat flux and peripherally constant surface temperature, both with longitudinally constant heat flux. It is found that even average heat-transfer coefficients may be different by an order of magnitude for these two conditions. For this reason, it is pointed out that solutions for a class of boundary conditions can be obtained by linear superposition of the results obtained for the two conditions mentioned.
Survey of Mathematical Methods for Nonlinear Control Systems
Authors: Loeb Julien M. 
Published: January 2022

Abstract
This paper is a survey of presently known mathematical methods applicable to nonlinear control problems. After emphasizing the need for general theories which alone can facilitate equipment design, the author discusses: a Phase-plane and phase-space methods for graphical representation of general system behavior; b describing-function analysis of limit cycles; c piece-wise linear analysis; d probability calculus for the study of noise and random inputs in nonlinear systems; and e energy-balance and stroboscopic methods which apply to particular features of a system.
Theory of Oil Whip for Vertical Rotors Supported by Plain Journal Bearings
Authors: Ørbeck Finn 
Published: January 2022

Abstract
This paper endeavors to show that by considering the pressure forces, the viscous drag forces, and the centrifugal forces acting on the journal in a plain journal bearing in oil whip, it is possible to obtain a rational explanation of this phenomenon. The conditions of force equilibrium of the journal lead to two equations, the first of which determines the ratio of frequency of whirl to frequency of rotation in terms of the eccentricity ratio. The second equation relates the eccentricity ratio to the frequency of rotation. These equations therefore suffice to describe oil whip in frequency and amplitude. Numerical studies of the problem indicate some agreement with published experimental studies.
Solution of the Tapered-Land Sector Thrust Bearing
Authors: Pinkus O. 
Published: January 2022

Abstract
Reynolds’ equation in polar co-ordinates was solved on a digital computer for the actual sectorial geometry of finite thrust bearings. The oil-film shape is that of a uniform taper in the circumferential direction. Minimum film thickness, side and end leakage, power loss, and centroids are given in general dimensionless form as functions of a dimensionless group (μN/P) (L/b)2. A wide range of bearing parameters is covered and solutions are given for very heavy unit loadings. A short discussion is included on how to perform thrust bearing calculations using the results and expressions derived in the paper.
Contribution to the Stability Theory of Systems of Surge Tanks
Authors: Jaeger Charles 
Published: January 2022

Abstract
The paper develops and discusses the theory of stability for two surge tanks in series on the same tunnel. The number of free parameters involved in the analysis is reduced to the point where a general discussion becomes possible. The effect of relative tank locations, diameters, and periods is discussed, and the importance of friction losses on the over-all stability.
Water Hammer in Nonuniform Pipes as an Example of Wave Propagation in Gradually Varying Media
Authors: Paynter H. M. , Ezekiel F. D. 
Published: January 2022

Abstract
Wave disturbances propagate down a fluid pipe, whose characteristics vary only gradually over a single wavelength, in nearly the same manner as a uniform pipe of the same total transmission time. However, the variations in pressure and flow along the pipe are modified directly and inversely, respectively, with the square root of the change in characteristic impedance level. This generally useful “Green’s Law” approximation is checked against exact solutions and other methods of approximation.
Three-Dimensional Photoelasticity and Its Application in Machine Design
Authors: Leven M. M. , Wahl A. M. 
Published: January 2022

Abstract
The simplest equipment, the best model materials, and the most effective techniques for three-dimensional photoelastic tests are described. The optical equipment involves only a simple diffusion polariscope using only a single camera lens. Phthalic anhydride-cured epoxy resins, which are relatively easy to cast in large sizes, have much superior properties for photoelastic tests than previously used materials. A simple technique of using surface slices and normal incidence of light will give adequate results for the stresses on free surfaces. At interior points, the effective stress can be obtained by measuring the retardation and isoclinic parameters on the three faces of random oriented small cubes. Some discussion is given regarding methods of applying the photoelastic results in practical design applications where fatigue, repeated strain cycling, plastic flow, and creep-rupture effects may occur during operation.