bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physical Basis of Air-Propeller Design
Authors: Caldwell F. W. , Fales E. N. 
Published: January 2024

Abstract
It is the purpose of this paper to summarize the conceptions of flight phenomena as developed by the use of the high-speed wind tunnel at McCook Field, Dayton, Ohio. The paper contains a description of the wind tunnel; a discussion of the phenomena discovered by its use; an analysis of propeller theory and application thereof to fan design; and a review of the methods employed for visualizing air flow.
The wind tunnel at McCook Field is notable, first, for the high velocity of air used (500 m.p.h.) and second, for means adopted to visualize the air flow. This latter is done by maintaining the humidity of the air in the tunnel at a certain predetermined level and by providing opportunities for its condensation where it shows the character of the air flow.
The study of air flow by these means gave new data on vortex formation created by the presence of aerofoils and made it possible to form a clearer conception of the conditions surrounding the operation of propellers.
The value of such investigations as can be made with the McCook Field equipment lies in the fact that hitherto the theory underlying flight phenomena has been purely rational and not directly applicable to engineering design because of the absence of empirical measurement of flight vortices. Because of this, it was impossible to predetermine the performance of aerofoils of new shapes, speeds, and sizes without first building a model and determining the particular coefficients applicable to the new design experimentally. Data obtainable in a wind tunnel having provision for visualizing the air flow are, however, the first step toward supplying this deficiency.
The authors show the application of some of the data obtained to the design of blowers and fans, and in an appendix the application of model wing tests to propeller design is discussed.
The Flow of Air Through Small Brass Tubes
Authors: Taylor T. S. 
Published: January 2024

Abstract
A study of the flow of air through brass tubes ⅝ in. (1.58 cm.), ⅞ in. (2.22 cm.) and 1½ in. (3.81 cm.) in diameter, respectively, has been made by means of small pilot tubes. Under the conditions of the experiment, it has been observed that the velocity distribution does not become constant in tubes of these dimensions until the air has passed through a length of about 6.57 ft. (200 cm.) The ratio of the average velocity to the maximum velocity at the center has been found to have a value of from 0.82 to 0.85 for all velocities for each of the tubes tested. Tests were made of the influence of dust and oil on the walls of the tubes and very interesting results obtained. A small quantity of dirt irregularly distributed greatly diminishes the total air flow for a given static pressure and also produces a marked change in the velocity distribution, the average velocity being made considerably less with respect to the maximum velocity.
Effect of Fittings on Flow of Fluids Through Pipe Lines: Including Chart for Flow of Saturated and Superheated Steam in Pipes
Authors: Foster Dean E. 
Published: January 2024

Abstract
The tables and chart developed in this paper afford a means of making proper allowance for resistance offered by fittings to the flow of liquids and gases through pipe lines. The tables which are based upon equations developed from formulœ giving flow of water and of high-pressure steam through pipes and the resistances offered to flow by fittings, give equivalent lengths of standard pipe to allow for various screw fittings in conduits carrying non-viscous liquids, steam, air or gas. The chart furnishes a means of rapidly solving problems involving the carrying of either dry saturated or superheated steam. Examples are given showing the use of the tables and chart.
Static Adjustment of Trucks on Curves
Authors: Eksergian R. 
Published: January 2024

Abstract
In the first part of this paper the adjustment of the running gear of a locomotive on a curve and the lateral reactions developed are considered from the geometrical limitations imposed which govern the length of wheelbase, the relation between lateral play and length of wheelbase, and the lateral displacement of trucks, together with a study of lateral devices for exerting guiding reactions between track and the frame of the rigid wheelbase.
The author then considers the effect of the major lateral reactions developed between the various parts of the running gear. The effect of the centrifugal force and the overturning moment which it produces resulting in a change of load on the non-crossed part of the equalization is next discussed in order to arrive at the proper journal loads in the design of the driving- and trailing truck axles. The principal reactions developed in a two and four-wheel engine truck and formulœ for the flange reaction of the guiding axle are developed in terms of the lateral reaction exerted at the center pin of the truck. An analysis is made of the lateral forces developed in skewing the rigid wheelbase of a locomotive in a curve. Finally formulœ for proper guiding and maximum flange reactions for the entire running gear are developed for three types of locomotives.
The third section is a recapitulation of the previous work with the object of keeping the various points outlined in working up a preliminary design.
Limitations of Mechanical Stokers Utilizing Mid-West Coals
Authors: Tenney Edward H. 
Published: January 2024

Abstract
In this paper the author discusses the limitations imposed on mechanical stokers by the use of Mid-West coals, which are characterized by higher moisture, volatile and ash contents as compared with Eastern Coals; the limitations imposed by air supply and by the design of the furnace; and the effect of these various limitations on stoker operation.
It is the author’s belief that in general the application of mechanical-stoking equipment to the use of Mid-West coals has proved to be eminently successful. Specially designed arrangements for air supply and to facilitate ignition of the fuel have been provided; and furnace volumes and gas passes have been scientifically studied, with the result that the most difficult problems — namely, those incident to operation at high rates of combustion — have been satisfactorily solved.
Graphical Methods
Authors: Marshall W. C. 
Published: January 2024

Abstract
After pointing out the value of graphical methods and the wide use which may be made of them, the author calls attention to the pressing need for the standardization of diagram forms in order that comparisons of the results plotted by different investigators on the same subject may be facilitated. So important does he deem the subject that he advocates a course in every school, college and university covering the use and construction of graphical diagrams together with the theory of graphical methods. Various types of diagrams in frequent use are described in the paper and the advantages of the alignment form are brought out.
An Investigation of Oxy-Acetylene Welding and Cutting Blowpipes
Authors: Johnston R. S. 
Published: January 2024

Abstract
This paper reports the results of and conclusions from an elaborate series of tests carried out at the Bureau of Standards Washington, D. C. on commercial apparatus for cutting and welding by the oxy-acetylene process, submitted by manufacturers for the purpose of the tests.
The test equipment used consisted of a weighing system for determining the weight of the gases used, a system for metering the gases as a check upon the weight and for maintaining standard conditions of pressure and temperature, a welding table for the welding tests, a cutting table for the cutting tests, and a “flashback” and safety testing apparatus for determining the conditions of the flashback phenomena.
Unusual precautions were taken to insure accuracy in all the tests. For example, the cutting tests were all made by a mechanically controlled cutting device installed on the cutting table, to eliminate the personal equation.
The welding tests were performed upon ½-in. and ¾-in. steel plates, and the cutting tests upon ½-in., 2-in., 6-in. and 10-in. material.
The general conclusions from the tests were that there was a great deal of difference between the characteristics of different designs of cutting blowpipes, and that there was no make of apparatus which was equally proficient and economical for all thicknesses of metal. Further, one of the prime essentials of a good welding blowpipe is its so-called gas ratio, which should be unity. Not any of the blowpipes tested proved capable of maintaining a gas ratio of unity during welding although, as the author states, the welds were probably made with greater care than has ever been bestowed upon any like work.
The important problem of “flashback” receives extensive consideration, and the author concludes by stating that experience gained during these tests indicates that a blowpipe designed to be absolutely free from flashback caused by any form of obstruction, under all working conditions, will also be the eminently safe blowpipe and the one which with ordinary care will produce sound welds. Such a blowpipe will be one so designed that, under all conditions of operation — even to complete blocking of the gas exit at the tip end, there will be maintained a one-to-one volume delivery of each gas, at identical pressures.
The Design of Large Locomotives
Authors: Haig M. H. 
Published: January 2024

Abstract
After discussing various restrictions and limitations in the design and construction of large locomotives due to the inability of existing bridges and tracks to of bridges and structures, the author expresses the opinion that the physical conditions of a road should be adjusted to the requirements of the locomotive, and that the only controlling factors should be the size of train and the traffic of the territory.
Leading features of locomotive construction such as relative size of cylinders, total heating surface, grate area, principal dimensions, etc., have been treated at length by various writers. Features which have not been so discussed, however, are those which keep a locomotive in service a maximum length of time, reduce engine failures to a minimum, reduce cost of maintenance and repairs, and increase revenue-earning power. And it is in order to arouse interest in those details which are not always given the attention to which they are entitled, that the author proceeds to their consideration. These, in the order of their treatment, are: Counterbalance, cross-heads, driving wheels, crosshead pins, piston rods, cylinders, frame braces, boiler cracks, back flue sheet, grate rigging, water columns, cab equipment, cab seats, and tender capacity. The author’s opinions on these topics are presented in the hope that discussion will bring out the experience of others not only on these but on additional details of locomotive design and construction.
On the Art of Milling
Authors: Airey John , Oxford Carl J. 
Published: January 2024

Abstract
This paper gives particulars of an investigation undertaken at the University of Michigan for the purpose of finding a rational basis for the action of a milling cutter.
It is shown that metal is removed more efficiently with thick chips than with thin chips. It follows from this that, other conditions being equal, including speed and feed per minute, the cutter with the fewest teeth gives the greatest efficiency. However, it is evident that the efficiencies of two cutters with different numbers of teeth are equal provided the table feeds be adjusted so that the same feed per tooth is effected. This gives a definite working theory on the influence of spacing.
It is definitely established that for a given material, tooth shape and sharpness, thickness of chip is the sole criterion of the efficiency with which metal is removed in milling and that increase of spacing over that required for free cutting is a handicap. Present-day high-powered cutters have several times the chip space needed. Limitation of machine power has doubtlessly been the chief factor in giving a false bias to the influence of spacing.
Formulas for determining the number of teeth for a known diameter of cutter and for determining the depth are included in the paper, as well as a geometrical construction for obtaining the best shape of tooth.
Porting and Charging of Two-Stroke Oil Engines
Authors: Illmer Louis 
Published: January 2024

Abstract
This paper deals primarily with single-acting semi-Diesel engines having the lower portion of the cylinder bore provided with intake and exhaust ports which are successively uncovered by the power piston as it approaches the end of its expansion stroke. In such engines the under side of the piston is generally made to serve as a low-pressure base chamber or crankcase pump for slightly precompressing the air supply and charging the power cylinder.
The advantages of this simple and effective method of charging the power cylinder are obvious, and the author undertakes to present a rational basis for predetermining the correct timing and porting of such valves. A considerable number of semi-Diesel two-stroke-cycle engines have been examined for port characteristics and some of the more promising designs have been critically analyzed to ascertain the reason for their superior performance. The results of this research disclose the particular combination of port relations and corresponding base pressures that are likely to give the best performance under any specific service conditions.
The various losses in fuel economy encountered in direct-injection oil engines are traced in some detail, and a new method is presented for estimating the expected power capacity of a given cylinder design as based upon the percentage of air that may be brought to the support of the injected fuel. The need of keeping all of the air charge in close proximinity with the spray valve and the importance of turbulence in effecting an even distribution of finely atomized fuel is also discussed. In closing, the author points out the line along which the further development of direct-injection or semi-Diesel engines should be looked for.
Avoidable Waste in the Operation of Locomotives and Cars
Authors: Elmer William 
Published: January 2024

Abstract
The average freight locomotive travels less than 60 miles per day. It spends about half of its time either in the hands of the transportation department moving trains or ready to move them, or in the hands of the motive-power department being repaired and prepared. There is naturally avoiduble waste in each department, and questions which may accordingly be asked relate to whether the engines are properly loaded and properly used. The present paper outlines the procedure for determining this, and one of its several appendices gives a method of working out the most economical tonnage for loading the freight engines of any division, based on actual practicable performance in everyday operation. The treatment considers the value of the locomotive, taking account of interest, depreciation and taxes; the relationship between straight-time and overtime rates for road crews; the quickening up of the time of the trains by a reduction of tonnage and the increase of the time the crews are on duty by an increase in tonnage. When these matters have been sufficiently studied in the light of the recorded facts, the question relating to proper loading can be intelligently answered.
The author discusses avoidable waste in the operation of cars under three heads: (a) Their utilization in the hands of agents, shippers and consignees; (b) their handling and dispatchment in yards and on the road; and (c) their repair and inspection.
Things contributing most to the reduction of waste in car and locomotive operation are coöperation and teamwork. If a division superintendent can be assured that everything is being done that can be done to have every available engine in service that can be put in service and that every engine dispatched is being loaded to the maximum number of cars it can economically haul, then he is assured of an economical performance and an avoidance of waste in the operation of both locomotives and cars.
Hidden Waste in Textile Plants
Authors: Gates Thayer P. 
Published: January 2024

Abstract
The purpose of this paper is to point out a few of the losses found in the average textile plant which have been very largely overlooked and which can be greatly reduced through the application of engineering research. The types of losses considered are mainly those occurring in the operation of equipment and the utilization of materials. The paper also points out the opportunities in the textile field for men of engineering training.
Application of the Law of Kinematic Similitude to the Surge-Chamber Problem
Authors: Durand W. F. 
Published: January 2024

Abstract
The problem of the hydraulic surge chamber gives rise to certain differential equations which do not admit of solution in analytical form. Under these conditions, various modes of treatment have been proposed. The present paper develops and describes a comprehensive experimental method utilizing the law of kinematic similitude. By this method a laboratory model of convenient dimensions is set up and subjected to a program of operation corresponding to that for the field installation. The movements of water level, times, etc., as measured for the model, are then multiplied by suitable relation factors, thus giving the results to be anticipated for the field installation.
The model may thus, in a sense, be considered as a form of mechanism which solves the equations as applied to the model form, and these results multiplied by suitable relation factors give the corresponding results to be anticipated in the field case.
The principal advantages of the model method are as follows:
1 The model is simple and readily set up. Once in operation, the most varied conditions may be quickly examined, thus making possible a range of examination in detail, the extent of which would be quite impracticable by any methods of numerical computation.
2 In all analytical methods of treatment, pipe-line friction has been assumed to vary with the square of the velocity. In the model method the friction may be taken to vary with vn, where n is usually found to be about 1.85.
3 In analytical methods the surge chamber is usually taken as uniform in cross-section. With the model, the chamber may be of any form whatever.
4 The model method is readily extended to the case of a surge chamber with spillway or to the case of multiple chambers on one pipe line.
5 The model method provides readily for the examination of periodic fluctuations in power demand, of any amplitude and any periodicity. The examination of such fluctuating programs is beyond practical reach by numerical methods.
Steel for Forge Welding
Authors: Speller Frank N. 
Published: January 2024

Abstract
In this paper the principal factors — method of manufacture, chemical composition, fluxing quality, susceptibility to heat and welding temperature — affecting the welding quality of steel are discussed and the average results of 80 tests made on forge welds of hammer-welded pipe are compared with the original material. In addition it is stated that tests have demonstrated that both steel not over 0.15 per cent carbon and minimum tensile strength of 47,000 lb. per sq. in. and that not over 0.20 per cent carbon and minimum tensile strength of 52,000 lb. per sq. in., are satisfactory for forge welding of pipe lines, penstocks, tank-car work and similar construction but that the former is best adapted for welded parts of boilers and pressure vessels. In conclusion the writer believes that the most important consideration to produce uniformly good results in the forge welding of steel, is suitable material, well-trained operators and adequate facilities for the control of operations.
An appendix is devoted to a presentation of the Tentative Specifications for Steel Plates for Forge Welding of the American Society for Testing Materials as revised in 1921.
Orifice Coefficients — Data and Results of Tests
Authors: Spitzglass Jacob M. 
Published: January 2024

Abstract
This paper discusses the results of experimental work conducted at the Research Laboratory of the Republic Flow Meters Co., of Chicago, on the use of orifice plates for measuring the flow of fluids in pipes.
Extensive tests were carried on for a period of several years to determine the effect of the varying factors such as the orifice ratio, the size of the pipe, and the distance of the upstream and downstream connections upon the pressure difference across the orifice plate. The tests were conducted on seven sizes of pipes, from 2-in. to 12-in. standard. Fourteen orifice ratios were used in each size and twelve connections were tested on each side of the orifice plate.
The tests were made on the flow of atmospheric air, supplied by a Sturtevant blower having a maximum capacity of 6000 cu. ft. per min., at a pressure of 10 in. of water. The air passing through the orifice was measured by five calibrated impact tubes ranging from 1 in. to 4 in. in internal diameter. A detailed account is given of the calibration of the impact tubes, and curves were plotted showing the coefficient as a function of the impact head through the tube.
The arrangement of the installation for the final tests is described and illustrated in detail, and an account is given of the method of testing the various orifices. The theoretical relation of the functions is given briefly, preceded by elaborate definitions of the terms involved. The paper includes a number of tables and a collection of characteristic curves that may be employed for determining the flow through orifice plates in a given size of pipe.
The Commercial Economy of High Pressure and High Superheat in the Central Station
Authors: Orrok Geo. A. 
Published: January 2024

Abstract
This paper is an attempt to examine into the theoretical relations between efficiency and pressure and temperature. During the investigation all of the available experiments on the variation of the strength of materials with temperature have been examined and certain inferences have been drawn. The variations in cost have been approximately evaluated and the conclusions of the discussion are stated in the summary.
Bending Stresses in Curved Tubes of Rectangular Cross-Section
Authors: Timoshenko S. 
Published: January 2024

Abstract
This paper analyzes the stresses in bent tubes of rectangular cross-section and shows that in the case of thin tubes the distortion due to bending results in greater flexibility and less strength than given by the usual formulas. In an appendix an approximate solution of the problem is obtained by a consideration of the potential energy of deformation.
Flow of Water in Short Pipes
Authors: Boston O. W. 
Published: January 2024

Abstract
The primary purpose of this paper is to present the method employed by the author in determining the frictional resistance or loss of head for water flowing in pipes. It is believed that this method, together with the mathematical determination of results, can be made use of in work of this nature at a great saving in time where tests in quantities are made for comparative analysis.
Data for mathematical interpretation are obtained by allowing a tank full of water to empty, the water flowing through the tube, pipe, valve, etc., calibrated. In this way all velocities within the head range are available in one test. The apparatus is simple and compact, making large weighing tanks and scales unnecessary.
Values for the coefficient of discharge of short tubes of diameters from 1 to 8 in., inclusive, are computed and tabulated for heads up to about seven feet.