bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Note on Limiting Laminar Nusselt Number in Ducts With Constant Temperature Gradient by Analogy to Thin-Plate Theory
Authors: Marco S. M. , Han L. S. 
Published: July 2022

Abstract
In this paper it is pointed out that the existing solutions for the deflections of thin plates under uniform lateral load and simply supported along all edges can be applied to the determination of the limiting temperature distributions in a fluid flowing in laminar motion in ducts of the same cross sections as those of the plates. The direct application of this solution is permissible only when (a) the axial temperature gradient is constant, with respect to both flow length and cross-section position. This implies uniform heating or cooling. (b) The cross section is a polygon. When the cross-section boundary contains curves, the constants of integration must be adjusted so that the boundary condition of nonslip flow is satisfied. Since the temperature and velocity distributions obtained by this analogy are expressed analytically, values of local heat transfer at any point in the cross-section boundary can be calculated. Examples are given for four cross sections, namely, rectangular, equilateral triangular, right-angled isosceles triangular, and semicircular. The heat-transfer distributions on the boundaries are calculated for square and equilateral triangular cross sections.
Dynamic Loads on Spur and Helical-Gear Teeth
Authors: Reswick J. B. 
Published: July 2022

Abstract
A simple model gives physical insight into the dynamic behavior of gears. Relationships developed from consideration of this model indicate that design criteria are significantly different in heavily loaded gears from those which are very lightly loaded. Results show that dynamic loads may be ignored in many heavily loaded gears, but that dynamic loads provide an important basis for the design of lightly loaded gears.
Effect of Supersonic Flight on Power-Plant Installation Systems
Authors: Keusch R. B. 
Published: July 2022

Abstract
This paper treats power-plant installation-system problems either brought on or aggravated by supersonic flight. These problems are in addition to those (treated elsewhere) of the basic engine; their magnitude and possible effect on the aircraft mission are treated. Among the power-plant installation-system areas considered are fuel systems, lubrication systems, power transmission, engine placement, air-induction systems, and cooling systems.
Temperature Problems of Equipment in High-Speed Aircraft
Authors: Adams H. W. 
Published: July 2022

Abstract
This paper takes an over-all look at the heat problem facing the equipment in the high-speed aircraft of the future. It discusses briefly the basic problem—the high temperatures that result when a body moves rapidly through the air; the kind of airplane and equipment that might be faced with the problem; methods of combating the problem; and the alternatives that are available to the airplane designer. The author concludes that up to speeds of 2 or 3 times the speeds that we are now flying, aircraft need not be limited by the high temperatures encountered.
Design of Offshore Drilling Structures
Authors: Howe R. J. 
Published: July 2022

Abstract
This paper is a condensation of part of the vast amount of published engineering information which applies to the design of offshore drilling and production structures. Owing to the rapid development within this field, the correlation between the theoretical and actual conditions has not been established firmly; however, additional experimental and operating information which will become available in the next few years should aid this problem considerably. The wind and wave forces which act on offshore structures are described in detail together with the soil reactions which hold the structures in place. The internal effects such as deflections, stresses, and natural frequencies also are discussed for a number of special cases. In addition, methods for calculating the floating stability of mobile units are presented. A general classification of offshore structures is given to illustrate the relative advantages of certain general types of structures.
The Statistical Nature of Friction
Authors: Rabinowicz E. , Rightmire B. G. , Tedholm C. E. , Williams R. E. 
Published: July 2022

Abstract
Sliding experiments have been carried out using copper surfaces in solid contact, and the friction traces have been analyzed statistically to study the spontaneous fluctuations in the friction force. The results suggest that the calculation of the standard deviation of the values of the instantaneous friction force can yield much information about the nature of the sliding process. High loads and smooth surface finish produce very steady traces for well-lubricated surfaces, while for unlubricated surfaces a rougher finish is required.
Compressibility Deviations for Polar Gases
Authors: Hall N. A. , Ibele W. E. 
Published: July 2022

Abstract
The departures of compressibility factors of polar gases from generalized compressibility charts have been noted by previous studies of gas compressibility as reaching such magnitudes as to reduce seriously the utility of such charts in describing the behavior of polar gases. Employing an “extended law of corresponding states,” this paper shows that polar-gas compressibility departures correlate with the “reduced dipole moment,” a parameter which is closely related to the molecular dipole moment of the particular polar gas. Charts are presented which permit the calculation of compressibility factors for polar gases by applying a polarity correction to the compressibility as given by a standard chart.
Total Normal Emissivity Measurements on Aircraft Materials Between 100 and 800 F
Authors: Snyder N. W. , Gier J. T. , Dunkle R. V. 
Published: July 2022

Abstract
The results of techniques developed and used to determine the mean effective emissivity of different surfaces over a range of temperatures from 100 to 800 F are presented. The measurement of radiant energy from the surfaces is accomplished by means of a 160-junction silver-constantan directional thermopile radiometer. Serious errors are noted and accounted for when improper use is made of polished shields in the experimental arrangements. This represents a refinement over previous techniques used; further refinements are anticipated with the ultimate aim of checking against integrated spectral data. However, the data presented are useful aids as a phase of the technique of evaluation of equilibrium temperatures of different surfaces exposed to solar irradiation.
The Short Bearing Approximation for Plain Journal Bearings
Authors: DuBois G. B. , Ocvirk F. W. 
Published: July 2022

Abstract
A method of analysis of short plain journal bearings is presented which eliminates the need of leakage factors and makes use of charts which have both analytical and experimental support. Eccentricity ratio, oil-film thickness, peak pressure, friction, and oil flow are obtainable for a given temperature. A method of estimating a maximum bearing operating temperature is suggested. Methods of evaluating the effect of elastic deflection and misalignment are also included. A method of determining a factor of safety is explained.
On the Solution of the Reynolds Equation for Slider-Bearing Lubrication—IX: The Stepped Slider With Adiabatic Lubricant Flow
Authors: Osterle F. , Charnes A. , Saibel E. 
Published: July 2022

Abstract
Treating viscosity as a function of temperature and pressure and taking approximate account of the variation of density, the load-supporting capacity of the stepped slider bearing with adiabatic lubricant flow is found. The importance of the “density-wedge” effect is noted and a numerical example is worked out illustrating the effect of different locations of the step on load capacity and comparing the performance of the stepped slider with the flat inclined-plane slider.
A Theory of the Fluid-Dynamic Mechanism of Regenerative Pumps
Authors: Wilson W. A. , Santalo M. A. , Oelrich J. A. 
Published: July 2022

Abstract
A hypothesis of operation of the regenerative pump is presented which reflects the experimentally observed characteristics of the flow inside the pump. An analysis based on the hypothesis leads to a series of expressions for pump performance over the entire operating range in terms of only three empirical constants. The relationship of these parameters to the prior art of hydrodynamic machinery and to those geometric features peculiar to regenerative pumps is developed. Experimental corroborations of the results are presented.
Thermal Conductivity of Gases
Authors: Keyes F. G. 
Published: July 2022

Abstract
A paper presented before the Heat Transfer Division at the 1953 Annual Meeting contains a description of the below-ice-point temperature apparatus for measuring thermal conductivities of gases and liquids, and a few results for neon were reported. During the past year low-temperature measurements have been made on the remainder of the rare gases, and also on other gases. Reliable results from thermal-conductivity measurements now appear to be forthcoming with the high-temperature apparatus to temperatures of 1380 F.
Heat Transfer and Fluid Friction for Fully Developed Turbulent Flow of Air and Supercritical Water With Variable Fluid Properties
Authors: Deissler R. G. 
Published: July 2022

Abstract
A previous analysis for fully developed turbulent flow and heat transfer in smooth tubes with variable fluid properties for a Prandtl number of one is generalized in order to make it applicable to air and supercritical water. Calculated velocity and temperature distributions as well as relations among Nusselt number, Reynolds number, and friction factor for both air and supercritical water with variable fluid properties are presented. Experimental local heat-transfer coefficients, friction factors, and velocity and temperature distributions, which were measured for air flowing turbulently in a smooth tube with heat transfer at large temperature differences, are included and compared with the analysis. Good agreement between analytical and experimental results was obtained for Reynolds numbers above 15,000.
The Unsteady-Flow Water Tunnel at the Massachusetts Institute of Technology
Authors: Daily J. W. , Deemer K. C. 
Published: July 2022

Abstract
A project to investigate fluid friction and cavitation phenomena in unsteady motion is under way in the Hydrodynamics Laboratory at the Massachusetts Institute of Technology. Its objective is to obtain for transient-flow conditions through conduits and around immersed bodies the same kinds of basic information that have been determined for steady-flow cases. A pilot-model water tunnel of unconventional design has been developed to produce flow in which the basic motion is accelerating or decelerating. It is of the blowdown type and consists essentially of two tanks 20 in. diam and 6 ft 8 in. long mounted vertically, one above the other, and connected by a tube, or working section of 1 in. ID. The velocity and acceleration of the flow through the tube are governed by the difference in air pressure above the water surfaces in the upper and lower tanks. This differential pressure, in turn, is controlled by a servosystem. High-frequency-response electronic cells were developed for measuring differential water pressures directly. These cells have been employed in experiments to determine loss of head along the test section and for measuring the instantaneous average velocity.
Reduction of Condensate-Line Corrosion
Authors: Jensen Scott , Lang E. R. 
Published: July 2022

Abstract
General accumulation of iron oxide and copper oxide or copper on boiler surfaces during service is almost always due to corrosion by water in the preboiler system beginning at the point where steam first condenses. The reduction of this corrosion will result in cleaner boilers and permit longer operation of the boilers between cleanings. This paper reports progress made in reducing iron and copper corrosion using ammonia, cyclohexylamine, morpholine, and sodium sulphite. The work was done at the Southern California Edison Company steam plants. This company supplies electric power to a large portion of Southern California by means of its hydroinstallations and its four steam plants. The reduction of corrosion in the condensate system at the Long Beach Steam Station and at the Redondo Steam Station is discussed.
Prevention of Babbitt Blisters in Thrust-Bearing Pads
Authors: Baudry R. A. , Gunther D. W. , Winer B. B. 
Published: July 2022

Abstract
Babbitt blisters were observed on water-wheel generator thrust-bearing pads. Investigation revealed that these blisters resulted from the accumulation of high-pressure hydrogen at the steel-babbitt interface. The hydrogen, it was found, came from the steel and was introduced during the manufacture of the steel. The maximum level of hydrogen content to insure freedom from blisters was determined. Processes to remove hydrogen from the steel were developed. The incorporation of these processes into the manufacture of thurst-bearing pads has resulted in the complete elimination of babbitt blistering.
Experimental Investigations of Propagating Stall in Axial-Flow Compressors
Authors: Iura T. , Rannie W. D. 
Published: July 2022

Abstract
Measurements of velocity fluctuations in stalled operation of an axial-flow compressor have demonstrated that stalling occurs for the most part in well-defined regions over the compressor annulus. These stalled regions rotate without changing shape in the direction of the blade rotation with a speed proportional to, but of smaller magnitude than, the rotor speed. Two principal types of propagating stall were observed, one with the stalled region or regions extending over part of the blade height, the other with a single stalled region over the full blade height.
Basic Compressor Characteristics From Tests of a Two-Stage Axial-Flow Machine
Authors: New W. R. , Redding A. H. , Saldin H. B. , Fentress K. O. 
Published: July 2022

Abstract
The attainable pressure ratio per stage and efficiency of axial-flow compressors, working at subsonic gas velocities, may be expected to depend at least upon Mach and Reynolds numbers additionally of all features of blading geometry. The results of a high-speed test program on a two-stage axial-flow compressor, with one easily defined and accurately reproducible choice of blading geometry, are reported in this paper. The tests covered a range of Mach numbers 0.3 to 0.9 and a range of Reynolds numbers 50,000 to 500,000. The relationships among the variables covered by this program are believed generally to be representative of the behavior of axial-flow-compressor stages at subsonic velocities even though absolute values of loading and efficiency are not indicative of the best current design standards. Three-dimensional diagrams showing the dependence of pressure ratio per stage and efficiency upon Mach and Reynolds numbers are included to aid in visualizing these relationships. The results are then condensed into pairs of two-dimensional plots exemplary of types more convenient for extensive use.
Heat Transfer to Mercury in Turbulent Pipe Flow
Authors: Johnson H. A. , Clabaugh W. J. , Hartnett J. P. 
Published: July 2022

Abstract
Experimental heat-transfer results are presented for turbulent flow of nonwetting mercury in a ¾-in., 18-gage mild-steel tube with constant heat flux. The identical test heat exchanger developed for the previously reported investigation of molten lead-bismuth eutectic (10, 11, 12) was used. This present investigation also includes a series of short-duration tests for possible effects due to secondary flow, the use of argon as an alternate for a helium-gas atmosphere, and the addition of magnesium-titanium amalgam as a wetting agent. Heat-transfer tests with water preceded and followed those for mercury to establish continuing reliable performance of the test exchanger and its instrumentation. The results are correlated for the Peclet modulus range from 200 to 10,000 and are 4 to 10 per cent lower than the previously reported values for lead-bismuth and 35 to 40 per cent lower than the Martinelli-Lyon momentum theory (15, 17). No difference in heat-transfer performance was noted for upward versus downward flow or for the use of argon as a replacement for the helium atmosphere. No visible evidence of wetting occurred on the addition of the magnesium-titanium amalgam and no effect was found in the heat transfer.
Thermal-Radiation Tables and Applications
Authors: Dunkle R. V. 
Published: July 2022

Abstract
In this paper the properties of ideal thermal radiators are tabulated in a generalized form for use with ideal sources at any temperature. These tables are presented in a form which simplifies the computation of total radiant properties from spectral properties for nonideal sources and receivers, and examples of their utilization are included. The values of the thermal-radiation constants utilized in the preparation of the tables were the latest available. Conventional engineering units are employed in this paper, conversion to other systems of units being accomplished readily. These tables were prepared from the tables computed by the Federal Works Agency, Work Projects Administration, after converting to engineering units and correcting for the revised values of the radiation constants.
On the Theory of Regenerative Chatter in Precision-Grinding Operations
Authors: Hahn R. S. 
Published: July 2022

Abstract
The phenomenon of regenerative chatter is discussed. An analysis is made, based on the proportionality of the instantaneous wheel depth of cut to the instantaneous dynamic force existing between wheel and work, which yields two stability criteria from the Nyquist diagram. The grinding system will be unconditionally stable if one stability criterion is satisfied. If this criterion is not satisfied a second criterion may yet be satisfied by proper adjustment of the cycles of vibration per revolution of the workpiece. A qualitative check on the theory is given.
1.5 Per Cent Carbon Cast-Steel Railroad-Car Wheels
Authors: Matthews N. A. , Flinn R. A. 
Published: July 2022

Abstract
A 1.5 per cent carbon cast-steel wheel, designated AARX-2, has been developed for freight-car service after 12 years of research and 6 years of evaluation by numerous laboratory and field-service tests. Pilot-plant production has been initiated to prove the economics of the process of manufacture. On the basis of two-and-a-half million car miles of service under typical and severe conditions, wear rate is comparable to that of one-wear wrought wheels. Little tendency for abnormal flange wear has been observed, and a minimum of “shellout” conditions are expected. Dynamometer and service tests have demonstrated conclusively that the wheel overcomes the thermal-checking problem which results from brake-shoe action. Ductility at the 1.5 per cent carbon level is achieved by a combination of close analysis control and a two-stage heat-treatment which produces a pearlitic structure with carbides favorably dispersed. The excess carbide promotes improved wear resistance at a given hardness level.
Heat-Treatments of Welded Structures for Relief of Residual Stresses With Particular Reference to Type 347 Stainless-Steel Weldments
Authors: Fleischmann W. L. 
Published: July 2022

Abstract
Welded ring samples of Type 347 stainless steel were given a number of different thermal treatments to study their effectiveness in relieving residual stresses. Treatment at temperatures of 1650 F and above caused complete relaxation. At lower temperatures the amount of relaxation obtainable in reasonable periods depended upon the magnitude of the residual stresses. Experiments conducted on twisted Type 347 stainless-steel wire showed that relaxation occurred at low temperatures. A treatment at 1100 F produced some untwisting and established a pattern of residual stresses that did not cause any further movement when the wire was cycled from room temperature at 850 F. High-temperature treatments produce metallurgical changes which may be of greater importance in conditioning the weld for the intended service than the fact that residual welding stresses were relieved. To emphasize the over-all effect of heat-treatments of welded structures, the use of the term “thermal-conditioning” is suggested in place of “stress-relieving.”
Thermal Checking of Wrought-Steel Railway Wheel Material
Authors: Wetenkamp H. R. 
Published: July 2022

Abstract
The mechanism of the formation of small cracks (thermal checks) that are formed as a result of two heat cycles is discussed. These thermal checks were noted in the treads of car wheels and careful examination of the conditions which caused them to form led to the development of a method of producing these thermal checks in a small specimen under better-controlled conditions. The reasons for the checks forming more readily in higher plain-carbon steel are discussed. Basically, the contraction of marten-site upon tempering seems to be the cause of the formation of thermal checks.
Pulverized-Coal-Fired Gasifier for Production of Carbon Monoxide and Hydrogen
Authors: Grossman P. R. , Curtis R. W. 
Published: July 2022

Abstract
This paper describes a pilot-plant pulverized-coal gasifier installed at the Morgantown Station of the Bureau of Mines and a semicommercial gasifier of similar design installed at the E. I. du Pont de Nemours & Company, Inc., Belle, West Virginia. A brief summary of the operating data obtained from these two units is presented and material requirements are given for this method of coal gasification. A large size unit of this design is now under construction and will go into operation next year. This will be the first commercial application of the process in this country. Details of the design that provide for handling of coal ash of widely varying fusing temperatures are given in an effort to point out those features which have contributed to continuous uninterrupted operation. Included also is a discussion of heat flow within the gasification unit to illustrate the factors involved in obtaining an economical process.
Characteristics of a Vaporizing Combustor for Aviation Gas Turbines
Authors: Pouchot W. D. , Hamm J. R. 
Published: July 2022

Abstract
An annular vaporizing-type combustor for an aviation gas turbine is described and its performance and operational characteristics are given. Test results show that the level of combustion efficiency at high altitudes is high and nearly constant over a wide range of fuel-air ratios. The other performance and the operational characteristics of the combustor have been found to be satisfactory. The outstanding advantage of the vaporizing combustor was its short length relative to a liquid-injection combustor developed for the same application.
Coefficients of Float-Type Variable-Area Flowmeters
Authors: Head V. P. 
Published: July 2022

Abstract
A uniform method of correlating flow data for all float-type variable-area meters is presented. Curves correlating the results of 73 calibrations of rotameters in ½-in. to 2-in. sizes and suitable for general flow calculation purposes are presented. Installation influences are discussed. A theoretical equation combining energy and momentum considerations is presented and compared with available data for incompressible flow.
Survey of Experimental Determinations of Heat Capacity of Ten Technically Important Gases
Authors: Masi Joseph F. 
Published: July 2022

Abstract
All of the literature reports of determinations of heat capacity of gases in the period 1925–1952, inclusive, are reviewed, and those pertaining to any of the ten gases—air, NH3, CO2, CO, H2, CH4 NO, N2, O2, and H2O—are tabulated. The four direct and six indirect methods used in these measurements are described briefly. By means of graphs, the reported results for several of the gases are compared with values calculated from molecular data and an equation of state. There is included a table of the most recent values of heat capacity at 1 atm for the ten gases.