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Technical Paper

Small Engine Emissions and Their Impact

1973-02-01
730859
In an attempt to characterize emissions from small air-cooled utility engines, five gasoline-fueled models were operated over a variety of speeds and loads, and important exhaust constituents were measured. These emissions included hydrocarbons, CO, CO2, NO, O2, aldehydes, light hydrocarbons, particulates, and smoke. Emissions of SOx were estimated on the basis of the fuel consumed; evaporative losses of hydrocarbons were also estimated. The impact of small engine emissions was calculated on the basis of the test results and information on national engine populations and usage. From these data, it appears that the 50 million or more small engines currently being used account for only a small part of pollutants from all sources.
Technical Paper

Advanced Nondestructive Testing Methods for Bearing Inspection

1972-02-01
720172
The principles of the magnetic-perturbation method of flaw detection and the Barkhausen noise residual stress measurement method are briefly reviewed. It is suggested that they provide very powerful tools for assuring improved ball bearing performance. The methods are applied for the evaluation of ball bearing races. Typical experimental results are presented along with metallurgical sectioning correlation.
Technical Paper

Diesel Exhaust Hydrocarbon Measurement - A Flame-Ionization Method

1970-02-01
700106
The design and development of an instrument for the measurement of total hydrocarbons in diesel exhaust are described, and its ability to measure steady-state and transient hydrocarbon emissions is indicated. The two-section system comprises a sampling train and flame-ionization detector and a chromatograph electrometer, recorder and backpressure regulator. A mixture of 40% H2 and 60% He was found to be the best fuel for low O2 response with the system. The method has been used for more than a year in evaluating hydrocarbon emissions from a wide variety of diesel engines under a number of typical operating conditions. The greatest advantage of the high-temperature system is its potential for expressing the total hydrocarbon content in diesel exhaust.
Technical Paper

Spectrometric Analysis of Used Oils

1969-02-01
690776
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.
Technical Paper

A Bench Technique for Evaluating High Temperature Oxidation and Corrosion Tendencies of Automotive Crankcase Lubricants

1968-02-01
680538
A technique for evaluating high temperature oxidation and corrosion tendencies of automotive crankcase lubricants is described. The technique utilizes a versatile bench apparatus which, with a minimum of modification, can be used for either evaluating thermal oxidation stability of gear lubricants or oxidation-corrosion tendencies of automotive crankcase lubricants. The apparatus is relatively compact and requires a minimal lubricant sample. Design of the apparatus permits close control of all operating parameters and provides satisfactory test data repeatability. Retainable copper-lead test bearings are used as the indicator in predicting a pass or fail of fully formulated crankcase lubricants as in the case of the CRC L-38-559 (Federal Test Method 3405) technique. Engine and bench test data are compared to illustrate the capabilities of this new bench technique.
Technical Paper

REDSOD - A New Concept in Earthmoving

1967-02-01
670271
REDSOD, an acronym for Repetitive Explosive Device for Soil Displacement, utilizes the energy generated within a combustion chamber by the combustion of compressed air and a hydrocarbon fuel to displace and move soil or material. An integral wedge-shaped base shoe with a large exhaust opening in its top surface is pushed into a soil overburden at depths up to 5 ft or more by a transporting vehicle. When the combustion chamber pressure has reached a maximum value, the hot, high pressure gases are released through the exhaust opening under the soil overburden. The soil is disaggregated and displaced up and out of the excavation. Deflectors can turn the direction of the soil's trajectory to deliver it to one side of the excavation. A greatly increased productivity per unit of equipment is possible over conventional earthmoving means.
Technical Paper

A Temperature Telemetry Technique for Reciprocating Engines

1967-02-01
670026
A unique system has been devised to measure and telemeter critical temperatures of reciprocating engine components. A prototype has been used to measure the piston pin bearing temperature in a full-scale EMD 2-567D diesel engine.
Technical Paper

Piston-Turbine-Compound Engine — A Design and Performance Analysis

1965-02-01
650632
Exhaust heat utilization for internal combustion engines has centered around turbosupercharging in recent years, neglecting the promising field of compounding a piston engine with a gas turbine in which, unlike turbocharging, turbine power is fed back to the engine crankshaft. The piston engine can cope with high gas pressure and temperature, whereas the gas turbine can efficiently utilize the energy at relatively low pressure and temperature and large volume flows. By compounding, this-piston engine will handle the high pressure, high temperature phase of the combustion cycle and extend the expansion ratio of the gases to atmospheric pressure by completing the low pressure, low temperature phase in the gas turbine. The marriage of the two engines will result in an outstanding power package with the highest thermal efficiency possible.
Technical Paper

Mechanisms of Dust Erosion

1964-01-01
640819
This paper shows the results of an experimental investigation of the nature and characteristics of erosion of metals by high-speed impingement of airborne dust particles. The influence of various parameters upon the rate of erosion is shown. The manner in which the rate of erosion varies with certain of these parameters indicates that erosion occurs through the ductile displacement of the eroded material by the impinging dust particle.
Technical Paper

Correlation of Prototype and Scale Model Vehicle Performance in Clay Soils

1964-01-01
640803
In an attempt to establish correlation between off-road performance of full-size vehicles and scale models in clay type soils by use of a similitude analysis, the U. S. Army Transportation Research Command (TRECOM) conducted a series of vehicle performance tests in three types of cohesive soils for a complete range of moisture content levels. This investigation covered a study of all soil parameters that could affect vehicle performance in low, medium, and high cohesion disaggregated soils, including the effects of vehicle weight, tire design, speed, slip, and soil characteristics on drawbar pull and tire sinkage. The results obtained and experience in testing techniques accumulated from this project are described.
Technical Paper

Passenger Car Hydrocarbon Emissions

1962-01-01
620005
This paper presents the results of an investigation of the normal sources of hydrocarbon emissions of passenger cars. The sources were considered to consist of the crankcase ventilation and exhaust systems, the carburetor, and the fuel tank vent. Many studies involving the emissions from several of these sources have been conducted and reported; however, it is believed that this is the first study designed to develop emission data from all the sources of a single group of passenger cars. Although only five vehicles were used, several mechanical conditions and engine and power train configurations were examined. The largest single source of hydrocarbon emissions was found to be the exhaust, followed by the road draft tube. Relatively minor emissions were measured as a result of fuel evaporation from the carburetor and fuel tank during periods of operation and hot soak.
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