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Viewing 163861 to 163890 of 185215
1969-02-01
Technical Paper
690730
G. E. Rich
Present deep submersible powerplants are limited in terms of on-board energy storage capacity. Of the planned advanced deep submersibles, the Deep Submergence Search Vehicle (DSSV) is an immediate and typical advanced power system application. This paper discusses DSSV power requirements and briefly outlines and compares the competing power system candidates. The pressure balanced, hydrazine-hydrogen peroxide fuel cell is identified as a leading competitor. A typical system approach is described, system design options identified, and system advantages cited.
1969-02-01
Technical Paper
690732
C. V. Burkland
A thermochemical powerplant for underwater applications featuring a low temperature Rankine cycle power loop and a fuel consisting of elemental boron slurried in a water carrier is described. The special features of the boron slurry fuel that make it attractive for underwater applications are detailed and some exploratory test results shown. A typical application to a deep operating submersible is examined and comparisons made with battery and fuel cell power sources.
1969-02-01
Technical Paper
690768
M. L. Haviland
Engine oil and automatic transmission fluid viscosities are major factors in assuring good starting and running performance in cold weather. To determine the contributions of the engine and transmission to the cranking and running effort, instantaneous torque and power, obtained with an instrumented engine-transmission apparatus, were determined for five engine oils ranging in viscosity from 4 to 184 poise (SAE 5W to SAE 20W) and for four transmission fluids ranging in viscosity from 3200 to 83,000 cp at -20 F. Specific engine and transmission cranking variables - engine friction, compression and expansion, engine rotational inertia, and transmission friction and rotational inertia - were analyzed in detail. The engine required most of the cranking effort, which increased with increasing engine oil viscosity. Increasing engine oil viscosity increased engine friction torque but decreased engine friction power because of decreased cranking speed.
1969-02-01
Technical Paper
690755
Robert H. Pish, Roy W. Hull
Small engines may require soundproofing to eliminate one or more of the following effects: hearing loss, speech interference, community annoyance, detectability, and psychological disorientation. Detectability criteria are frequently associated with military applications and may require the use of a soundproof enclosure in addition to other engine treatments. Acoustical noise sources are conveniently classed as either aerodynamic or mechanical. Aerodynamic sources are predominant on small engines. Treatment of exhaust noise by individual components, e.g., muffler, is inadequate; a system approach, through the use of an electro-acoustic analog computer, has proved to be a much more satisfactory procedure.
1969-02-01
Technical Paper
690766
T. E. Kashmerick
This paper emphasizes the need for correct component specification in the procurement of a vehicle so that expected performance results can be obtained. Areas of component selection affecting vehicle ride, handling, durability, and performance are utility body application problems, tire and wheel effects, related frame stiffness, and fifth wheel location problems. Besides mechanical factors, interstate fleet operational problems with varying legal requirements by states will have an effect on vehicle usage. Basic selection factors reviewed are vehicle capability from gvw-gcw characteristics and component minimums, correct selection of wheelbase, and component matching to static and dynamic requirements. In conclusion, it is recommended that an immediate evaluation of a vehicle under actual operating conditions be conducted to determine its true effective capability.
1969-02-01
Technical Paper
690754
L. Brown William
This paper outlines the procedure used at Perfect Circle to determine coating application parameters, to evaluate coating quality, and to evaluate coating performance for new piston ring coatings. It includes descriptions of bench tests, procedures for measurement of physical properties, and descriptions of test techniques The paper outlines a sound engineering approach to developing and evaluating wear coatings for piston rings which can be extended to other coating applications.
1969-02-01
Technical Paper
690757
J. M. Adgey, A. B. Birks, G. P. Blair
Modern turbocharged diesel engines employ exhaust driven turboblowers operating at high speeds up to 100,000 rpm. The performance assessment of such units demands precise and controllable power absorption and torque measurements at these very high rotational speeds. Additionally the parameters, speed, mass flow, static and dynamic pressures and temperatures must be measured. The turbine power absorption and torque measutement present unique problems. The remaining parameters may present some difficulties but generally the problems are not so great. The design of a high speed dynamometer and the development problems encountered are described. The dynamometer has been used to establihs the performance characteristics of a C. A. V. 01 turbocharger and these are reported.
1969-02-01
Technical Paper
690758
A. A. Johnston, L. L. Stavinoha
The tendency of motor gasolines to form deposits on the intake valve and port surfaces of spark-ignition engines can be evaluated by a bench apparatus developed for the U.S. Army. The apparatus consists of a carbureted fuel-air system which sprays the test fluid on a heated deposit collecting tube at a 2.0 ml/minute rate. Combat gasoline (MIL-G-3056C), commercial (or VV-G-76) gasolines, and special solvents can be evaluated, using a sample volume of 150 ml. The results obtained by this technique have been correlated with data obtained during a military vehicle fleet test. The procedure has also been used to study effects of gasoline additives, storage conditions, and storage duration on fuel degradation, and as an aid in the development of deterioration predictive tests. The results of a round-robin tests for reproducibility initiated at Army petroleum testing laboratories within the United States, are provided.
1969-02-01
Technical Paper
690748
W. Krautter
Combustion engines with up to 48 cyl have been built. It is shown that this is neither accident nor fanciness when high specific power output is involved. As is demonstrated on hand of equations, the subdivision of a certain displacement into larger numbers of smaller cylinders brings about a substantial increase in power. At this time, for example, more than twice that of single cylinder engines. Values of highly developed motorcycle competition engines are compared with these theoretical results and an amazingly high degree of agreement exists. These laws are not limited to motorcycle engines, but may be used for other applications also.
1969-02-01
Technical Paper
690740
J. E. Rich
This paper is a critical discussion of various problems which one company encountered with accessories on several different makes of gas-fired turbines. These turbines are used as prime movers driving centrifugal natural gas compressors on a pipeline transmission system. The accessories covered are: ignition system, lube oil cooler, tach generator, lube oil pumps, auxiliary gearbox, thermocouples, lubricators, inlet air filter, instrument air system, cab pressurization fan, and starter.
1969-02-01
Technical Paper
690739
George W. Barrett
The development of aircraft and gas turbine powerplants has resulted in engine specifications and technical requirements which are increasingly difficult for the engine controls and accessory design engineers to satisfy. The objective of this paper is to review the approaches being taken by the controls and accessory designers in an attempt to meet the challenges of engine control at minimum weight long life with maximum reliability over a wide range of environmental conditions for future engines.
1969-02-01
Technical Paper
690738
H. E. Porte
An advancement in electrical power generation has been developed which improves the quality of power for airborne and ground-based electrical components. The improved power will allow electrical components to be designed smaller and lighter in weight. The accuracy of positioning devices and radar equipment is improved as a result of a more closely regulated frequency. The reliability and maintainability of the power equipment is higher than the equipment in use today because fewer moving parts are involved in converting the variable engine speed to a constant frequency electrical power. The equipment will require less maintenance, thus reducing downtime and the cost of ownership. The VSCF system has many advantages which put it into a classification of an advanced electrical system.
1969-02-01
Technical Paper
690742
Charles W. Grennan, Evert von Moltke
The driving of fuel pumps by the gas turbine shaft is shown to offer potential savings in weight and size when the total accessory package and drive is considered. This is achieved by modifying standard pumping concepts in order to retain current performance and endurance characteristics. A review is presented showing the benefits of different pump concepts to engines of different power ratings.
1969-02-01
Technical Paper
690743
J. F. Murray
Higher pump speeds and pressures with the consequent increase in output per pound is the surest way to meet the reduced pump weight required in future gas turbine engines (1).* This paper discusses problems associated with operating pumps at engine shaft speeds or on drives independent of the engine. Mechanical and hydraulic problems related to different fluids, contamination, and minimization of fluid temperature rise are covered. In some recent engines, pumps have been operated successfully at higher speeds and pressures. Current pump speeds, however, are still far short of the smaller gas turbine shaft speeds. The paper covers the present state-of-the-art, current development programs, and a projection of future developments toward higher pump speeds.
1969-02-01
Technical Paper
690778
Ralph McClintock
Rear axle tapered roller bearing wear has been studied in bench and car tests, using both commercial and experimental gear lubricants. In bench tests, magnitude of wear was affected by both lubricant additive treatment and lubricant viscosity; increased wear resulted from reduction in viscosity with lead soap-active sulfur and Pb-S-Cl lubricants but not with P-S and Zn-P-S-Cl lubricants. Substantial decreases in wear from one bearing lot to subsequent lots apparently resulted from mechanical improvement in the bearing manufacturing technique. These wear decreases, for a given bearing speed and load combination, were accompanied by decreased temperature and thickness of roller-end surface film formed from the lubricants. In rear axle car tests run as far as 94,000 miles, P-S additive package blends having viscosities as low as 4 cs at 210 F performed satisfactorily, although bearing wear was somewhat greater than that with P-S blends having viscosities of 9 cs at 210 F.
1969-02-01
Technical Paper
690771
F. M. Winn
Oilwell servicing techniques have caused the evolution of specialized vehicles to meet operational requirements. Present designs are not adequate by either performance or economic standards to meet today’s service. Future vehicle design parameters will necessitate a different approach by the vehicle manufacturers to satisfy an increasing domestic and foreign market. The purpose of this paper is to present some of the limitations of present equipment and suggest requirements to be considered in future design.
1969-02-01
Technical Paper
690769
R. M. Stewart, C. R. Spohn
A reciprocating viscometer which was used for determining cold-cranking properties of engine oils was modified so it could be used to predict low-speed, hot-cranking properties of crankcase oils in full-scale engines. Since the current 210 F ASTM D 445 viscosities of multigrade oils fail to predict their hot-cranking properties, there is need for such a unit. A high degree of correlation was obtained between the 210 F viscosities determined with the modified reciprocating viscometer and those determined using a full-scale test engine for a group of V.I. improved oils and a group of commercial premium multigrade crankcase oils. The correlation obtained between the two units for a group of 5W oils containing oiliness agents indicates the viscometer to be satisfactory for screening tests. In general, this viscometer can satisfactorily predict low-speed, hot-cranking properties of oils in full-scale engines quickly and economically.
1969-02-01
Technical Paper
690773
W. C. Pike, R. F. Pywell, S. G. Rudston
Chromium wear phenomena of three types have been investigated using a continuous radio-tracing technique in single cylinder engines. The dependence of wear on load at high wall pressures was studied in a gasoline engine using taper faced rings. It was confirmed in a laboratory diesel engine that ring wear was primarily corrosive. Techniques were developed for the rapid assessment of lubricating oils and additives and some detailed examinations of effects of additives and their concentration have been made. Finally, ring scuffing in the gasoline engine was promoted by thermal distortion.
1969-02-01
Technical Paper
690774
W. E. Waddey, A. F. Pearce
A taxicab test was conducted to determine the effect of motor oil composition on engine wear. It was found that detergent-inhibitor treat, antiwear additive level, viscosity and V.I. improver type all affected wear in one or several engine areas. Moreover, it was shown that with an optimum balance of components, multigrade oils can be designed which are as effective in controlling wear as single-grade oils.
1969-02-01
Technical Paper
690777
Robert Bee Lewis
The outstanding dry friction characteristics of Teflon TFE can be imparted to a variety of filled and reinforced compositions, many of which offer superior unlubricated wear performance. A logical extension is the application of filled TFE as marginally lubricated or thin film lubricated bearings. Under conditions of very thin film lubrication, some filled compositions of Teflon outperform conventional materials, such as babbitt and bronze. Guidelines for using filled compositions of Teflon with water lubrication are explored. Comparative test results are examined in light of theoretical relationships between thin film lubricated friction and wear performance.
1969-02-01
Technical Paper
690776
L. L. Stavinoha, B. R. Wright
This paper discusses the techniques and diagnostic significance of atomic absorption, atomic emission, and infrared spectrometric analysis of crankcase lubricants, with the use of supplementary data where pertinent. The parameters affecting used oil analytical data are discussed in terms of examples from Army general purpose vehicle test engines. Wear metals in used gear oils are also discussed and examples are given. Analytical methods and their applications are fully described, and the equipment and procedures for infrared spectroscopy and gas chromatography techniques are outlined.
1969-02-01
Technical Paper
690064
T. Trojanowski
Farm implement sizes are increasing rapidly. The increases in rotating mass, the uneven load cycles, and the high probability of impact loads inherent in farm applications result in peak drive train torque loads which are very high compared to the average torque required. This paper discusses the conditions under which these peak torques arise, and the effects of torsional elasticity in reducing these peak torques, thus reducing stresses on all drive train components such as universal joints, gears, shafts, and so forth.
1969-02-01
Technical Paper
690057
H. W. Ellison, G. L. Van Ermen
One of the functions of the Fastener Technical Section at GM Engineering Staff is to investigate the basic variables which affect fastener torque-tension relationships. The primary tool used for these investigations is the FTS Torque-Tension Test Machine. This machine has the capability of applying and measuring the torque to tighten, the resulting tension, the shank torque in the bolt, the number of degrees of rotation, and driver speed and air line pressure. In typical torque-tension testing, the tension in the fastener, the total tightening torque, and the torque in the bolt shank are measured using strain gaged load cells. In order to minimize test, and particularly, data reduction and analysis time, a computerized recording system is used. As a test is run, electrical signals from the load cells are stored and then automatically read into an IBM 1800 computer.
1969-02-01
Technical Paper
690060
William R. White
Sandwich structures provide high stiffness at low weight and the use of polyurethane foam core has provided a versatile material for some time. Polyurethane duromer is the name of a new material which can produce a strong structural sandwich composite molding with integral solid urethane skins and a microporous core. Skins and core are produced simultaneously in a single operation from identical raw materials. The process is similar to injection molding, at relatively lower costs. These factors may provide the impetus to efforts directed toward making automotive body panels of plastic in economical mass production.
1969-02-01
Technical Paper
690059
R. C. Burck
Cast solid urethane elastomers can be formulated to vary some properties. The injection molding grade urethanes can be blended with other plastic resins to lower cost and to modify properties. There is now a trend toward custom formulation for specific end use applications. Microcellular urethane elastomers combine the “toughness” of solid urethanes with the advantages of a cellular structure. This material performs as a self-compensating bumper. It responds gently to light loads but firms up under heavy loads. Microcellular elastomers are now used commercially in a number of automotive applications such as auxiliary springs, under-car bumpers, vibration dampeners and seals.
1969-02-01
Technical Paper
690053
David R. Grove
The development of a windshield antenna for automobiles is discussed. A review of the program since 1957 is presented, then the author describes various problems encountered in constructing an acceptable windshield antenna.
1969-02-01
Technical Paper
690056
J. J. Lawser
The practicability of specific hole sizes is known to be influenced by power tool dynamics, material characteristics, finishes, and screw type. Less attention has been paid to resulting internal thread geometry. Historically the engineer controlled tapped hole thread geometry by appropriate thread form specifications. The advent of thread-forming screws has seriously limited his direct knowledge of internal thread geometry. This paper derives the important geometrical parameters for internal threads produced by thread-forming screws. Equations relate internal thread geometry to external thread form and hole size. Without complete standards for thread-forming screws, the technique is illustrated for a Type C and a sharp crested nonstandard thread form. Percent thread and percent volume filled between threads are given by charts.
1969-02-01
Technical Paper
690050
S.R. Swanson
At the present time, it is generally conceded that testing for the evaluation of fatigue performance of materials subjected to variable loading in service, must contain variable loading as well. Single-level fatigue testing just will not provide an accurate answer. Two methods of fatigue testing using variable amplitude have been advocated in the literature. The earlier method, developed by Gassner, involves the stratification of the service load spectrum into eight levels, from the maximum load to the minimum. The number of cycles at each level is developed from the load spectrum. The loads are then applied in a stepwise ascending-descending manner beginning with a mid-level. The second method involves the use of a clipped random process, whose intensity (RMS) is varied throughout the test in a random stepwise manner, such that the final accumulation of loads is asymptotic to the desired load spectrum. These two methods are examined in detail in this paper.
1969-02-01
Technical Paper
690052
Russell G. Whittemore
A typical electrically heated, tempered backlight is described and its merits listed. Design criteria including line or stripe spacing, width, and location, together with bus construction and electrical reinforcement are discussed. Defogging and deicing capabilities are reviewed. Variations in power output with ambient temperature are particularly noted. This new product appeared on some 1968 American automobiles as an option, and on additional 1969 models. It is an important contribution to safety because of improved visibility to the rear.
1969-02-01
Technical Paper
690046
Sotiris S. Kitrilakis, Edward F. Doyle
Three steam engine driven prototype portable generator sets ranging in power from 100 W (e) to 1500 W (e) are described. To a large extent, these sets have demonstrated the potential capability of the Rankine cycle for low noise, low exhaust emissions, high reliability, acceptable efficiency, and multi-fuel operation. Design criteria used in the development of these units and their general applicability to reciprocating Rankine cycle systems are discussed. Recent developments make this power cycle attractive for commercial applications in present sizes as well as in scaled-up versions.

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