bluuebunny/crossref_metadata_2025_split huggingface dataset:
Engineering Features of the Union Oil-Shale Retort
Authors: Reed H. C. , Berg Clyde 
Published: July 2022

Abstract
The retorting of shale requires an operation combining very good heat and fuel economy with low capital investment. In order to meet these demands the Union Oil Company developed its novel underfeed retorting method, which was publicly demonstrated in 1950 in a 50-ton per day unit. The retorting unit employs countercurrent flow of shale and air in a kiln utilizing bottom feed of solids. Ash and clinkers are removed overhead, and the oil drained from the bottom of the unit is cooled by countercurrent heat exchange with the incoming shale. No water is required for process operation. Movement of the shale through this unit is effected by a hydraulically operated underfeed mechanism. The shale kiln employs an external retorting section with cowling to direct air flow over the fins and to control shell temperature. Unlike conventional retorts, fusion of ash is not considered a problem in the operation of the Union retort since specially designed sodium-filled plows carry out a scraping action in the plastic ash-fusion zone, maintaining uniform bed porosity and size range of the discharged ash. It has been estimated that a typical commercial shale mine can produce approximately 20,000 tons per day of shale. The shale-retorting plant designed to handle this production would employ a battery of retorts, each having a capacity of 1000 tons per day, and centralized gas-handling and hydraulic power-supply systems.
Full-Scale Fatigue Testing of Compressor Cylinders
Authors: Kuivinen T. O. 
Published: July 2022

Abstract
Present needs for higher-pressure compressor cylinders for natural-gas pipe lines introduce complexities of design and manufacture. Through full-scale fatigue testing, designs incorporating high-strength cast irons are proved suitable at considerable saving to the user. Comparison of the fatigue-test failure of the design to the fatigue strength of the material used indicates the maximum safe working pressures permissible for various suction pressures. In this manner a new design is evaluated, eliminating the risks involved in former practice where field service was the only criterion of performance.
On the Solution of the Reynolds Equation for Slider-Bearing Lubrication—III: Effect of Transverse Curvature
Authors: Charnes A. , Saibel E. , Ying A. S. C. 
Published: July 2022

Abstract
The effect of transverse curvature on the properties of a rectangular slider bearing with side leakage is studied for film thickness varying exponentially in the direction of motion and symmetrically perpendicular to this direction. A perturbation technique allows the expression of the results in terms of the same type of simple solution previously obtained without transverse curvature. Thus the solution is convenient for all length to width ratios and entrance to exit clearances.
Vibrations in Knee-Type Horizontal Milling Machines
Authors: Bendixen Ivar 
Published: July 2022

Abstract
This paper outlines a series of tests on vibrations in knee-type horizontal milling machines, especially in the knee system. The amplitude of the vibrations was determined by means of a capacitive pickup. Systematic investigations on the importance of clamping and unclamping the various elements are made. The influence of damping in the case of resonance is pointed out. An explanation of the vibration accompanying entrance and exit of the milling cutter is indicated. A theory for the presence of low natural frequencies in the knee system is developed. Up- and down-milling are compared.
Mechanical Properties of Glass-Cloth Plastic Laminates as Related to Direction of Stress and Construction of Laminate
Authors: Werren Fred 
Published: July 2022

Abstract
Methods are available for predicting the directional properties of glass-cloth plastic laminates from a knowledge of the properties associated with their natural axes. The mechanical properties of cross-laminated or composite laminates may also be calculated from the basic properties of parallel laminates made of the component fabrics. Tests at the Forest Products Laboratory have shown that the suggested methods are reasonably correct for the range of glass-cloth plastic laminates presently being used in aircraft.
Contamination of Condensate by Heat-Exchanger-Tube Alloys
Authors: Ristroph J. D. , Powell E. B. 
Published: July 2022

Abstract
Results are presented from condensate contamination studies conducted at two steam power stations to evaluate the influence of temperature of condensate, of differing dissolved gas content, and of cumulative service time upon the degree of metallic contamination to be expected in steam condensate of the general character described from flowing contact with tubing of twelve alloys commercially used in power-plant heat exchangers. The influence of cyclohexylamine on the rates of contamination is also indicated. The testing procedures are briefly described.
Creep of Neoprene in Shear Under Static Conditions; Ten Years
Authors: Keen W. Newlin 
Published: July 2022

Abstract
This paper, representing more than a decade of research on the static creep of neoprene vulcanizates, supplements a previous paper by the author. The test procedure is given, and the effects of composition, age, and temperature on the creep characteristics of the vulcanizates are reported. The author’s data indicate that neoprene vulcanizates can be designed with creep-resistant properties equal to or superior to those of natural rubber.
The Venturi as a Meter for Gas-Solids Mixtures
Authors: Farbar Leonard 
Published: July 2022

Abstract
This investigation was undertaken to determine the behavior of a Venturi tube when metering the solids phase in a gas-solids mixture for the condition of constant gravimetric gas-flow rate. The Venturi tubes were used in both a horizontal and vertical section of 17-mm-ID glass conduit and had throat diameters of 0.500 in. and 0.375 in., respectively. The gas-solids mixtures consisted of air and alumina-silica catalyst (an aggregate mixture containing a size range varying from 10 to 220 microns) with solids loadings as high as 10 lb of solids per lb of air. Results on four different gas-flow rates indicated a linear relationship between the Venturi pressure differential and the solids-flow rate over the range of loadings attainable with the experimental equipment. The linear relationship was observed for each Venturi size in both the horizontal and vertical location; the slope of these lines increased with increased air-flow rate and decreasing Venturi throat diameter. Pressure recovery in the diffuser section of the Venturi was observed and found to vary in nonlinear fashion with the solids rate. It appears that the Venturi may be used with satisfactory results in the metering of a solids phase in a gas-solids mixture when the gravimetric gas-flow rate is held constant. In plants and pilot plants handling powdered solids by pneumatic conveyance, the Venturi may serve as a useful tool in indicating any instantaneous changes in the solids-flow rate as well as the gas-flow rate.
Pressure Distributions on the Blade of an Axial-Flow Propeller Pump
Authors: Morelli D. A. , Bowerman R. D. 
Published: July 2022

Abstract
Propeller pumps with small numbers of blades are usually designed by applying airfoil-strip theory using the tabulated properties of airfoils in a linear flow field of infinite extent. The velocity at each radius is taken as the relative velocity obtained by vector combination of the tangential velocity, the axial velocity, and the induced velocity at the mid-chord of the blade. For few blades the induced velocity at a blade resulting from the presence of other blades usually is ignored. Since the facilities and techniques at the authors’ disposal make it relatively easy to obtain pressure distributions on the moving elements of hydraulic machinery, a comparison was made between the calculated and measured pressure loading on a single-bladed axial-flow impeller. The results show that the design method used, which differs only in a minor way from the usual method given in the technical literature, gives a close approach to the actual loading at the design point. The experimental data are presented in sufficient quantity to show how the blade loading varies with flow rate over the whole of the blade and that the free-vortex condition is fairly well achieved in the neighborhood of the design point. Generally, it is concluded that the airfoil theory can give a close approximation to the performance and loading of a blade of a propeller pump in spite of the considerable departure from the ideal conditions for which it was developed.
A Lathe Test for the Evaluation of Cutting Fluids
Authors: Oathout J. D. , Howell W. C. , Hamer J. P. , Leland H. L. 
Published: July 2022

Abstract
A full-scale lathe test procedure is described which offers a sound and reproducible laboratory method for evaluating cutting-fluid performance. This test is based on tool-life measurements in a single-point turning operation on steel. Testing technique and data treatment are presented. Results show excellent general correlation with field-performance tests under widely varied cutting conditions.
Power Required by Carbide-Tipped Face-Milling Cutters
Authors: Gilbert W. W. , Boston O. W. , Siekmann H. J. 
Published: July 2022

Abstract
Fundamental data on high-speed milling were derived from two research projects conducted in the period 1944–1946, the results of which were made available by this Society in the form of data sheets. However, these individual data sheets have been difficult to use because of their large mass and lack of correlation. The data dealing with the power requirements as influenced by the setup conditions when face-milling with sintered-carbide tools have been organized and are presented in this paper.
The Lubrication of Gyroscopes
Authors: Brophy J. E. , Romans J. B. 
Published: July 2022

Abstract
The lubrication requirements of a number of gyroscopes have been studied as a prerequisite to the development of improved rotor-bearing lubricants and with the additional objective of replacing proprietary lubricants by one or more lubricants to be specified in the future. The gyroscopes studied included both air-driven and electrically driven types. Measurements were made of bearing temperatures, rotor speed, rate of deceleration, power input, and bearing noise level, the noise components being analyzed. A small high-speed evacuated gyro failed by the time 650 hr of operation had been reached. The other gyros studied all operated without bearing failure for a minimum of 10,000 hr on the specified lubricants. Two electric gyros have operated satisfactorily for 10,000 hr on synthetic diester-type lubricants. Gyro repair facilities reported that the paramount problem in overhaul work is that of obtaining suitable replacement bearings. It has become evident that causes of abnormally short rotor-bearing life include the use of inferior replacement bearings, poor overhaul techniques, and careless handling of equipment. Some of the proprietary lubricants are not suitable for use in instruments which are in storage for long periods.
Some Vibration Effects on Surfaces Produced by Turret Lathes
Authors: Eisele P. T. , Griffin R. F. 
Published: July 2022

Abstract
This paper shows the nature of the turned surface produced by a turret lathe under some low-frequency vibration conditions. In shop language the surface is referred to as a “barber-pole finish” or a “spiral cut.” Conditions causing this type of surface are shown together with a theoretical analysis. Some data on vibration magnitude and surface roughness are given. A discussion is included on the degree of balance obtained in commercial motors and its effect on surface finish.
Calculation of Transpiration-Cooled Gas-Turbine Blades
Authors: Livingood J. N. B. , Eckert E. R. G. 
Published: July 2022

Abstract
Methods for an analytic determination of the local coolant flow required to maintain a constant prescribed wall temperature for a transpiration-cooled gas-turbine blade are discussed. In the laminar-flow region, approximations for bodies of arbitrary shape obtained at NACA from wedge-type flow solutions are employed. In the turbulent-flow region, the Rannie-Friedman theory for a transpiration-cooled flat plate is used. Calculations for an arbitrarily chosen transpiration-cooled gas-turbine blade are presented. Recovery factors for a transpiration-cooled flat plate and verification of an existing method for correlating flow data for porous surfaces are included. Finally, a discussion of some of the difficulties associated with the problem of obtaining the proper local coolant flow is given.
Local Heat-Transfer Coefficients on Surface of an Elliptical Cylinder, Axis Ratio 1:3, in a High-Speed Air Stream
Authors: Drake R. M. , Seban R. A. , Doughty D. L. , Levy S. 
Published: July 2022

Abstract
Local heat-transfer coefficients and thermal-recovery factors from a 1:3-axis-ratio elliptical cylinder to air are presented for angles of attack of +6 deg, 0 deg, and −6 deg with reference to the wind-tunnel center line. Air speeds ranged from 150 to 440 fps, yielding Reynolds numbers based on the major axis of the cylinder of 4.34 × 105 to 1.28 × 106. The heat transfer was measured experimentally for the primary purpose of providing results which would be a basis for a check of the approximate methods for predicting the heat transfer in the laminar-boundary-layer region. This check has been made for one method of prediction with satisfactory results for the various flow geometries.
Investigation of Flame Temperatures in a Single-Cylinder Spark-Ignition Engine
Authors: Potter J. H. , Dillaway R. B. 
Published: July 2022

Abstract
The measurement of flame temperatures in the cylinder of an internal-combustion engine has enlisted the interest of many researchers. This paper reports on experimental flame-temperature determinations in a spark-ignition engine using the electro-optical system proposed originally by Graff. For calibration, the sodium D-line-reversal technique was employed. Statistical methods were applied to the temperature-crank angle and pressure-crank angle oscillograms obtained from the electro-optical technique, to reduce individual cycle values to average engine levels. The importance of the Graff method as a research tool is reviewed.
Dynamic Operation of a Force-Compensated Hydraulic Throttling Valve
Authors: Bower J. L. , Tuteur F. B. 
Published: July 2022

Abstract
If the characteristics of a hydraulic control valve are fairly regular, a linear analysis can be applied provided that the input is of low amplitude. Such an analysis reveals that the valve can be considered as a fairly simple feedback loop, particularly if valve and load are approximately symmetrical. Application of standard techniques used in feedback circuits indicates one cause for valve instability and also yields an expression for the valve-transfer function. The analysis may be broadened considerably by use of analog computing techniques which make it possible to remove the requirement on small input amplitudes.
Quick-Starting of Large High-Pressure High-Temperature Boilers
Authors: Falkner Jefferson C. 
Published: July 2022

Abstract
In the near future the Consolidated Edison’s generating stations will be faced with routine week-end 24 and 48-hr shutdowns of large, single-unit, high-pressure, high-temperature turbines and boilers. As a result of week-end load drop and the opening of the new Astoria Station— with heat rates approximately 20 per cent better than those of existing plants—the annual number of starts from cold on high-pressure boilers will increase greatly. It is with this prospective situation in mind together with a conviction that quick-starting from cold of large high-pressure boilers, when properly handled, is less rigorous on the expanding boiler structure than present 5 to 6-hr starts, that this investigation was carried out. By means of test results this paper demonstrates that safe operating procedures can be developed to bring 1,000,000 lb of steam per hr, high-pressure, high-temperature boilers equipped with high-pressure-drop superheaters from a cold condition to on-the-line in 1 to 2 hr. The paper explains some of the operational techniques and fundamental concepts relative to such accelerated starts. It also presents data on the handling of both the topping and condensing turbines in connection with cold boiler starts.
Quick-Starting of High-Pressure Boilers—Discussion: Factors Involved in Starting and Subsequent Loading of Modern Steam Turbines
Authors: Elston C. W. 
Published: July 2022

Abstract
Increasing numbers of high-pressure high-temperature turbines are being subjected to frequent shutdowns, in many cases nightly. Designers and operators of these units must give careful consideration to the factors involved and by co-operative effort develop optimum techniques and procedures for starting and loading steam turbines. Suggestions are given in this paper of such procedures.
Large-Extrusion-Press Operation and Production Problems
Authors: McCormick T. F. 
Published: July 2022

Abstract
Giant presses now under construction or planned in this country will enlarge by severalfold the size of light-metal shapes and tubes that may be extruded. The operation of the new presses will present many production problems, both predicted and unpredicted, but at the same time will permit the extrusion of large or intricate shapes which lead to economy and versatility in aircraft construction. A review of operating techniques and problems associated with present large extrusion presses points out some of the expected problems and emphasizes the increased scope of the extrusion process to provide metal shapes designed for the utmost usefulness.
Forces in Dry Surface Grinding
Authors: Marshall E. R. , Shaw M. C. 
Published: July 2022

Abstract
A dynamometer is described for measuring independently the normal and tangential forces in surface grinding. These forces are correlated with such variables as wheel speed, table speed, depth of cut, direction of table motion, grit material and size, specimen hardness and dressing technique. Specific energy is found to be the best criterion for interpreting grinding data. X-ray diffraction methods are employed to study the surface stresses and the depth of cold work induced by grinding.
Surface Temperatures in Grinding
Authors: Outwater J. O. , Shaw M. C. 
Published: July 2022

Abstract
Heat-transfer theory involving a moving heat source is applied to the grinding process to obtain an equation for the mean surface temperature in grinding. This equation predicts surface temperatures as high as 3000 F for a representative fine grinding operation. The analysis shows that in finish-grinding the surface temperature is reduced by decreasing the chip depth of cut but in snagging operations the surface temperature may be reduced by increasing the chip depth of cut. Representative values of the mean temperature between the chip and the grinding wheel obtained by the toolwork thermocouple technique are presented and discussed. The role of the grinding atmosphere in the production of sparks and in determining the energy involved in grinding is illustrated by experimental data. When the oxygen concentration of the atmosphere is very low, the specific grinding energy is found to be unusually high. The existence of high surface temperatures in fine grinding operations is demonstrated by the presence of a transformed surface layer that is largely retained austenite.
Centrifugal Jet-Pump Combinations
Authors: McConaghy J. W. 
Published: July 2022

Abstract
The widespread use of the water jet combined with a centrifugal pump to create what is commonly called a “jet pump” for domestic water systems, directs attention to the determination of its operating characteristics in terms of its components. The relative importance of this type of pumping equipment is illustrated by Department of Commerce data which show that in 1948 fifty-six companies shipped 649,143 units having a factory value of $50,704,294. Of these, 325,220 were of the jet type valued at $27,298,250. While the units are usually small and can be tested readily to obtain data on the operating characteristics, an engineering analysis would serve to emphasize the essential design constants.
Catalytic Effect of Several Metals on the Oxidation of Lubricating Oils
Authors: Sawyer D. W. 
Published: July 2022

Abstract
Considerable evidence has accumulated to show that aluminum is especially well adapted for the construction of many types of equipment for handling lubricating oils such as sumps, coolers, pistons, pumps, crankcases, and tubing. Therefore, to gain more quantitative data, a study has been carried out at the Aluminum Research Laboratories to compare the effects of various metals and alloys on the properties of lubricating oils at several temperatures. On the basis of this investigation, it appears that aluminum alloys and stainless steel have only a very slight or no catalytic effect on the oxidation of mineral oils and are more resistant than many of the other metals evaluated. Copper and low-carbon steel were found definitely to have an adverse effect upon the properties of the oils.
The Creep and Stress-Rupture Testing of Steam-Boiler Materials
Authors: Romer J. B. , Newell H. D. 
Published: July 2022

Abstract
This paper points out the necessity of having adequate data on the high-temperature properties of metals used in steam-boiler construction. The significance of the time factor in testing in relationship to long-life high-performance steam-generating equipment is discussed as are the general effects of metal oxidation from steam and combustion atmospheres. Metallurgical stability of steels is important in maintaining creep strength and is necessary to prevent severe modification of mechanical properties through effects such as spheroidization of carbide phase, graphitization or formation of sigma phase in highly alloyed steels. The relative merits of long-time creep tests and stress-rupture tests are considered, and typical test data are cited for each form of test. These data are necessary for design of superheater tubes and headers, alloy baffles, hangers and fittings, and are an aid to the Code Committee in assigning suitable stress allowances for materials. The paper gives suggestions for temperature limits for superheater-tube materials and a résumé of field experience on carbon and alloy steels. Conclusions are drawn that high-temperature creep and rupture testing have been very useful in evaluating the relative strength of steels for high-temperature use, in aiding in the development of superior materials, and in permitting the increases in steam temperature and pressure which have led to much greater economy in power production. Further advances are forecast for the future through a well-co-ordinated program of metal testing now in progress.