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Viewing 15301 to 15330 of 15349
1924-01-01
Technical Paper
240001
G A YOUNG, J H HOLLOWAY
Investigations indicate that detonation may be controlled by retarding the rate of combustion by chemicals added to the mixture, which serve to increase its specific heat and prevent excessive temperature, and by reducing the temperature of the walls of the combustion-chamber, so that the temperature of the charge previous to ignition will be lower and thus insure a normal rate of combustion. The present discussion is devoted to methods of controlling the temperature of the charge before and after the mixture enters the combustion-chamber, and before normal ignition occurs. Tests previously made on a poppet-valve engine and on a sleeve-valve engine revealed the impracticability of applying the laboratory methods used at that time to commercial practice and the need of eliminating some of the difficulties inherent in those methods of detonation control. The various changes made in the engine are described, including the specially designed spark-plugs.
1923-01-01
Technical Paper
230024
OSCAR W SJOGREN
1923-01-01
Technical Paper
230051
A H FRAUENTHAL
It is stated that an out-of-round surface having an even number of high-spots requires a checking instrument that has opposed measuring points; and that, if the number of high-spots on the surface is uneven, an instrument having three-point contact, and one of the points of contact located on the center line between the other two, is necessary. Concerning the use of the three-point method, for close work, the angle between the three points of contact must be selected according to the number of high-spots. Divisions of the subject include types of out-of-roundness and those peculiar to certain machines, the three-point measurnig system, errors of the V-block method, use of the V-block for elliptical objects, other methods of checking elliptical forms and indicator-reading correction. Three items for instrument improvement are suggested to manufacturers.
1923-01-01
Technical Paper
230001
H M CRANE
1923-01-01
Technical Paper
230002
V H GOTTSCHALK
The author describes a series of road service-tests, made on stock cars driven by their usual drivers when using fuel of specified grades, to determine the effect of any changes in the fuel volatility on the gasoline mileage for the respective make of car, as part of a general research program undertaken jointly by the automotive and the petroleum industries. The object was to determine the best fuel as regards volatility, from the general economic standpoint, and what grade of fuel would afford the maximum car-mileage per barrel of crude oil consumed. Factors influencing the selection of cars used are enumerated and the fuels tested are discussed, together with general comment and a description of the test procedure. The results are tabulated and commented upon at some length, inclusive of descriptions of the methods. A summary of the results is presented in the form of conclusions that are stated in four specific divisions.
1923-01-01
Technical Paper
230007
J H HOLLOWAY, H. A. HUEBOTTER, G A YOUNG
This Annual Meeting paper is a report of a series of tests conducted during the summer of 1922 by the authors at the Engineering Experiment Station of Purdue University. The work consisted of research into the operation of internal-combustion engines under comparatively high compression on ordinary gasoline without detonation. The compression-ratio of the engine was 6.75 and the compression pressure was 122 lb. per sq. in., gage. The ingoing charge was passed through a hot-spot vaporizer and thence through a cooler between the carbureter and the valves. Jacket-water temperatures between 150 and 170 deg. fahr. were carried at the outlet port of the jacket. The theory held by the authors as to the causes of detonation of the combustible charge is presented briefly. The source of the two phases of detonation encountered in this work is believed to be overheated areas in the combustion-chamber.
1922-01-01
Technical Paper
220009
ROBERT E WILSON, DANIEL P BARNARD
The term “oiliness” is defined as that property of lubricants by virtue of which one fluid gives lower coefficients of friction (generally at slow speeds or high loads) than another fluid of the same viscosity. Its importance under practical operating conditions is shown to be greater than is generally recognized. Unfortunately, however, no satisfactory method has ever been developed for the quantitative measurement of this property in comparing different lubricants.
1922-01-01
Technical Paper
220010
Winslow H. Herschel
ABSTRACT
1922-01-01
Technical Paper
220004
THOMAS MIDGLEY, T A BOYD
The various methods employed to measure detonation or fuel knock in an internal-combustion engine, such as the listening indicator, temperature and bouncing-pin, are discussed and the reasons all but the last cannot be employed to give satisfactory indications of the detonation tendencies of fuels are given. The bouncing-pin method, which is a combination of the indicator developed by the author and the apparatus designed by Dr. H. C. Dickinson at the Bureau of Standards, is illustrated and described. In this method the evolution of gas from an electrolytic cell containing sulphuric acid and distilled water measures the bouncing-pin fluctuations in a given period of time. The accuracy of this method of comparison is brought out in a table. The qualities that a standard fuel must possess are explained and the objections to a special gasoline are pointed out.
1922-01-01
Technical Paper
220032
H C DICKINSON
Dr. Dickinson outlines the history of the Research Department since its organization, indicates why the universities are the principal bases of operation for pure research, describes how the department functions as a clearing-house with regard to research data and comments upon the bright prospects for the future. He enumerates also the facilities the Research Department has for the coordination of research problems. The practical achievements of the Department have resulted from its recent concentration upon the three major projects of study with regard to the tractive resistance of roads, with reference to fuel and to testing programs, and of an effort to render financial assistance to the Bureau of Standards and the Bureau of Mines that would enable these Bureaus to continue their elaborate research programs, details of all of this work being included.
1922-01-01
Technical Paper
220014
S VON AMMON
As a result of the general policy of the Motor Transport Corps to standardize the materials used for automotive vehicles for Army Service, in cooperation with the Bureau of Standards, the Society of Automotive Engineers and the automotive industry, the Bureau of Standards has been engaged for some time in developing a standard method for testing brake-linings. While the work is not complete, much information has been gained. This paper reports the progress of the work. The equipment developed and the methods used for both main and supplementary tests are described. Information is given regarding the coefficient of friction, as influenced by various factors. The endurance test, showing the comparative behavior of linings under conditions similar to those of severe service, is believed to be satisfactory as developed. Further work is necessary before recommending the conditions for the other test, intended to determine the relative endurance under ordinary or light service.
1922-01-01
Technical Paper
220022
C N. DAWE
1922-01-01
Technical Paper
220063
GEORGE E A HALLETT
The general method of procedure taken by the Air Service before beginning the actual design and construction of the necessary types of aircraft engine is outlined and the four steps of the development subsequent to a very complete study of existing domestic and foreign engines are stated. After checking over the layouts, if all the details are agreed upon by both the designer and the Engineering Division, the contract is placed, usually for two experimental engines, and the construction work is begun. Acceptance tests are made to demonstrate that the engine is capable of running at normal speed and firing on all cylinders. These are followed by the standard performance test made on the dynamometer at McCook Field. The results of the latter test determine whether the engine can enter the 50-hr. endurance test. The engine is then torn-down and inspected for wear. Suggested modifications are embodied in reconstructed engines which eventually fulfill the requirements.
1922-01-01
Technical Paper
220051
CORNELIUS T MYERS
After pointing out that the publication of articles in the trade and technical journals, to the effect that very considerable weight-reductions in motor-truck construction with consequent savings in gasoline and tires are possible, works an injustice to the motor-truck industry and is misleading, the author outlines some of the reasons why such weight-reductions are very difficult to effect, as well as the possibilities of standardizing axle details. The use of aluminum to effect weight-reduction is commented upon and the various advantages claimed for metal wheels are mentioned. In the latter connection the author points out that, while these claims may be true, they are unsupported by reliable data. The greater part of the paper is devoted to an account of a series of tests conducted by a large coal company to determine the relative merits of wood and metal wheels on its trucks.
1920-01-01
Technical Paper
200002
O C BERRY
The paper is based upon the results of tests made by the Purdue Engineering Experiment Station to study the effect upon engine performance of varying the proportions of fuel to air in the mixture, and its object is to determine the variation in the mixture requirements of an engine at different rates of flow of air through the carbureter. The method of conducting the tests is described. The results are plotted in the charts shown and are discussed in some detail, special discussion regarding the effect of speed and load being presented, and the facts brought out by the tests are summarized. In the general discussion that follows, four definite conclusions regarding the richness of the fuel mixture in its relation to the maximum power are stated, and a like number of definite conclusions concerning the richness of the mixture in relation to maximum efficiency are also given.
1920-01-01
Technical Paper
200009
BENJAMIN LIEBOWITZ
The five fundamental criteria of the performance of a motor vehicle as a whole are stated. Riding comfort is investigated at length with a view to determining methods of measurement of the two classes of vehicle vibrations that affect the riding qualities of a car, so that suitable springs can be designed to overcome them. The underlying principles of the seismograph are utilized in designing a specialized form of this instrument for measuring vehicle vibrations, the general design considerations are stated and a detailed description is given. This is followed by an explanation of the methods used in analyzing the curves obtained, thus making possible a standardized measurement of riding comfort. The factors determining riding comfort are then analyzed in connection with spring-development work, the most important are summarized and the preliminary experimental results of those directly determined by the seismograph are outlined.
1920-01-01
Technical Paper
200032
C A NORMAN, B STOCKFLETH
A four-cylinder 4 by 5-in. truck and tractor engine, designed for either kerosene or gasoline fuel and having the very low volumetric compression ratio of 3.36, was used. Only by suitable adjustments was it found possible to make it show a fuel consumption as low as 0.67 lb. per b.hp.-hr.; but with a slight variation in power and only a different carbureter adjustment the fuel consumption at 600 r.p.m. increased to about 1.2 lb., or 70 per cent, emphasizing the importance of knowing what constitutes the best engine adjustment and of disseminating such knowledge. The engine and its dimensions, the experimental apparatus and the method of testing are fully described and discussed, the results being presented in charts showing performance curves. These are described, analyzed and the results interpreted.
1920-01-01
Technical Paper
200028
LEON W CHASE
To test tractors for results valuable to the user, the reliability, durability, power, economy and utility should be determined. Standard tests measuring tractor utility and reliability are impossible practically and durability tests would be an extensive project, but tractor and engine-power tests and tests of the amount of fuel required for doing a unit of work can easily be made. The University of Nebraska tests described were for belt and drawbar horsepower and miscellaneous testing for special cases. The four brake-horsepower tests adopted are stated. Tractor operating conditions are then reviewed. The drawbar horsepower tests include a 10-hr. test at the rated load of the tractor, with the governor set as in the first brake-horsepower test, and a series of short runs with the load increased for each until the engine is overloaded or the drive wheel slips excessively, to determine the maximum engine horsepower.
1920-01-01
Technical Paper
200042
V R GAGE
A large number of tests were made in the altitude laboratory of the Bureau of Standards, using aircraft engines. The complete analysis of these tests was conducted under the direction of the Powerplants Committee of the National Advisory Committee for Aeronautics. Many of the engines were of the same make, differing in compression ratio or dimensions. The testing program included determinations of the brake-horsepower at various speeds and altitudes, or air densities, and the friction power, or the power required to operate the engine with no fuel or ignition at various speeds and air densities, with normal operating conditions of oil, water and the like. Some tests included determination of the effect of change of mixture ratio and of air temperature, and of different oils. The difficulties caused by the necessity of using indirect methods to ascertain the effect of various factors are outlined. The test analyses and curves are presented.
1919-01-01
Technical Paper
190049
E H BELDEN
Efficiency, appearance and comfort will be the catchwords of the car of the future. Extreme simplicity of chassis will be needed to reduce weight and permit the use of substantial sheet-metal fenders, mud-guards and bodies. The center of gravity should be as low as possible consistent with good appearance. For comfort the width and angle of seats will be studied more carefully and the doors will be wider. A new type of spring suspension is coming to the fore, known as the three-point cantilever. Cars adopting it will have a certain wheelbase and a longer spring base. A car equipped with this new mechanism has been driven at 60 m.p.h. in safety and comfort without the use of shock absorbers or snubbers. It is the opinion of the author that this new spring suspension will revolutionize passenger-car construction.
1919-01-01
Technical Paper
190038
P J DASEY
THE rapid development of heavy-duty trucks and farm tractors has made it necessary for manufacturers of engines used in such automotive apparatus to face problems regarding which there is no past experience to fall back upon. The necessity in both types of engine for maximum strength in all parts carrying excessive loads constitutes a problem of great importance, but in addition to it are others of the proper utilization of fuels at present available, lubrication under excessive load conditions over long periods of time; and, of nearly as much importance, the relation of fuels to lubricants and the effect of fuels upon lubricants. Moreover, information is to be acquired regarding the value of prospective fuels as power producers, the effects they have upon engines, lubricants, etc., comparisons of cost and the like. The tests recorded in the paper were made in an endeavor to ascertain some of these unknown values.
1918-01-01
Technical Paper
180013
O W A OETTING
1918-01-01
Technical Paper
180027
W G CLARK
1917-01-01
Technical Paper
170005
F. HYMANS
The author points out the necessity of obtaining dynamic or running balance of rotating parts, especially in automobile-engine construction. He discusses the manifestations of the lack of static and running balance, such as vibration and high bearing pressures. Formulas are supplied for calculating bending moments and centrifugal forces in a crankshaft that is out of balance. Methods for obtaining static balance are described and the possible conditions existing after static balance is obtained are treated, with especial reference to the existence of one or more couples. Descriptions are given of two representative machines that are used to locate couples and correct for them. The principles of operation are made clear and advantages and disadvantages of each type are brought out fully.
1917-01-01
Technical Paper
170003
WALTER T. FISHLEIGH, W. E. LAY
The authors outline some of the problems that confront the automobile engineer today, showing how the demand for better performance and economy and the ever-increasing cost of volatile fuels has emphasized the necessity for thorough engineering work in the successful automobile manufacturing plant. Believing that the accurate analysis of the heat distribution in a modern automobile engine will be of great value, the authors describe a comprehensive test, made under their direction, of such an engine. This test includes measurements of the brake horsepower, friction horsepower, fuel consumption and heat losses to jackets, exhaust and cooling air. The engine tested was inclosed in a hood, similar to that used on the car in normal service and an air blast was directed through this hood at speeds approximating those at which the engine would drive a car with a given gear ratio.
1917-01-01
Technical Paper
170015
WALTER T. FISHLEIGH
1917-01-01
Technical Paper
170043
R. M. ANDERSON
This paper emphasizes the importance of using standardized testing equipment in order that mental calculations may be avoided in interpreting the reports of other engineers. The situation and environments of the engine-testing plant, cooperation among the men conducting tests, standardized methods of conducting tests, value of venturi meters and testing of accessories are among the subjects discussed in the first part of the paper. The subject of the testing of engine cooling systems is treated at some length, the importance of obtaining operating conditions being emphasized. The paper concludes with two sections covering spark-plug testing and tests for preignition.
1915-01-01
Technical Paper
150009
R. B. Mudge
1915-01-01
Technical Paper
150010
GEORGE W. HOUK
Viewing 15301 to 15330 of 15349