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1968-02-01
Technical Paper
680125
Stuart W. Martens, Kelly W. Thurston
A sealed plastic enclosure was proposed in February 1967 by HEW as a technique for measurement of fuel system evaporative emissions from an automobile. Early work with this technique uncovered problems such as car background emissions. Subsequent experimental work, however, has solved these problems and has shown the sealed enclosure capable of correctly measuring total vehicle evaporative emissions. Fuel vapors that actually reach the atmosphere can be measured in a simple, direct way without the necessity for vehicle modification. A complete description of the enclosure is given and its use by GM is described.
1968-02-01
Technical Paper
680124
P. Eyzat, J. C. Guibet
The theory presented here allows forecasting of nitric oxide emissions in spark ignition engines. Following preliminary review of possibilities of obtaining the equilibrium state, as well as the basic concept of medium temperatures, the authors suggest using kinetic calculations for estimating the NO content of both unburned and burned mixtures. After good correlation is obtained, particularly for lean mixtures, the calculation is used to determine the best combustion process by simulation on a computer. Since experiments show an important effect of the fuel-air heterogeneity, complementary simulating work is conducted in order to define the best fuel stratification laws.
1968-02-01
Technical Paper
680123
Lamont Eltinge, Frederick J. Marsee, A. Joel Warren
The combination of lean mixtures to provide oxygen in the exhaust and of exhaust heat conservation to enhance exhaust reactions yields significant exhaust reaction and lower hydrocarbon emissions. It requires adequately uniform mixtures, but does not require injection of additional air into the exhaust. A vehicle with this combination exhibits low emissions and good performance and fuel economy. Full evaluation of this approach must await general application. The results of this experimental exploration are presented as a contribution to the multi- industry effort to provide the public with acceptable atmospheric cleanliness at minimum vehicle and fuel cost.
1968-02-01
Technical Paper
680122
K. E. Klinksiek
Various vehicle emission regulations and test procedures and their influence on Volkswagenwerk AG are described. Early planning of worldwide legislation is recommended. Information is given about flexible instrumentation and procedures to overcome the problems with different regulations. Emission test results of cross-checks between different test procedures are reported. The results show that correlation is possible to some extent. But a broad spectrum of correlation factors has been found.
1968-02-01
Technical Paper
680114
Lamont Eltinge
Charts have been developed that, from the composition of gasoline-engine exhaust, indicate quickly and easily: 1. Fuel-air ratio of the mixture inducted into the engine. 2. Uniformity of mixture distribution and completeness of combustion. 3. Internal consistency of the set of exhaust-composition measurements. Calculation of fuel-air ratio from exhaust composition is common, but the charts have advantages in some applications and less sensitivity to error in CO2 determinations. Determination of mixture uniformity from total exhaust composition appears to be new. The charts provide a worthwhile check on instrument accuracy, which is not an integral part of other F/A techniques.
1968-02-01
Technical Paper
680113
G. D. Ebersole, G. E. Holman
Hydrocarbon and carbon monoxide concentrations in the exhaust of an engine equipped with a closed positive crank-case ventilation (PCV) system were kept at low levels with operation on high-quality motor oil when compared with similar operation on a low-quality motor oil. The increase in exhaust emissions with the low-quality motor oil resulted from the effects of deposit accumulation in the PCV valve, carburetor venturi, and carburetor throttle body areas.
1968-02-01
Technical Paper
680112
L. S. Caretto, E. S. Starkman, Ron Chin
A proposal for a tracer method to be used in the investigation of fuel effects is made. In addition, preliminary results of a tracer investigation of exhaust emissions in a Wankel engine which burns an oil-fuel mixture (NSU KKM 507/3) are reported. It is hoped that the tracer technique proposed here will be able to elucidate the nature of the chemistry of the combustion process in engines, in particular those processes leading to atmospheric pollution. The initial study examined the relative contribution of each component of an oil-fuel mixture to incompletely burned material in the exhaust. It was found that the oil contributed a disproportionate amount to the total emissions prior to an engine overhaul when the rotor seals were replaced. Subsequent to this the proportion of incompletely burned material attributed to the oil was the same as the proportion of oil in the initial oil-fuel mixture.
1968-02-01
Technical Paper
680111
John N. Pattison, Clark Fegraus, A. J. Andreatch, John C. Elston
In support of the Federal regulations which limit hydrocarbons and carbon monoxide emissions from new motor vehicles, the State of New Jersey has passed a law which is intended to require that vehicles with these controls, as well as vehicles without controls, be kept functioning properly. The law states that all motor vehicles subject to inspection pass a test annually to show compliance with standards to be set by the Department of Health. This paper describes the development of a 1 minute test for measuring and evaluating the crankcase and exhaust emissions for carbon monoxide, hydrocarbons, and smoke. It involves putting the vehicle on a simple set of inertia rolls and driving a simple cycle, called the ACID cycle, that was developed for this test. The exhaust is collected by either a variable dilution or variable flow system and analyzed for hydrocarbons, carbon monoxide, and carbon dioxide.
1968-02-01
Technical Paper
680110
D. L. Hittler, L. R. Hamkins
Requirements of federal and state agencies to control the exhaust emissions of motor vehicles defined performance standards for 1968. Consideration of economics and practicality motivated a full scale design and development program to meet this required performance without the use of a secondary control system. An analysis of new low quench type combustion chambers compared with the standard chambers used on two displacements of a 6-cylinder engine family in prior model years is presented in terms of parameters related to exhaust emission and to conventional engine design. The engine induction system, with special emphasis on carburetor characteristics, is contrasted for application to non-emission controlled engines with application to emission controlled engines.
1968-02-01
Technical Paper
680108
Ȧke O. J. Larborn, Folke E. S. Zackrisson
The Volvo Exhaust Emission Control System is an engine modification system employing the dual manifold principle, lean mixtures, idle spark retard, deceleration bypass valves, and increased idle speed. The design and performance of the system are described, including the influence on the Federal cycle results of various factors such as idle speed and idle mixture adjustment. Fuel economy, octane requirement, etc, is also discussed. Results of durability test are reported.
1968-02-01
Technical Paper
680109
J. T. Wentworth
Wide variations in exhaust hydrocarbon concentration have been traced to the angular position of the top compression ring gap. Furthermore, with a fixed gap position, equally large changes in exhaust hydrocarbon concentration have been correlated with blowby flow rate, which was chiefly determined by the smallest of the two compression ring gap areas. Enlarging gap area increases blowby volume, which lowers exhaust hydrocarbon output. It is believed that the air-fuel mixture in the piston-bore-ring crevices escapes combustion and that both gap location and blowby flow influence the amount of this hydrocarbon-laden gas which makes its way into the exhaust gas. A modification of the piston and top ring, called the sealed ring-orifice design, has demonstrated the technical feasibility of reducing exhaust hydrocarbon concentrations by minimizing the crevice effect, while cutting blowby flow below that possible with production rings.
1968-02-01
Technical Paper
680089
Erwin Eisele
The modern, small, high-speed, 4-stroke diesel engine above all owes its development of today’s speeds of 4500 rpm to the objective of making it applicable to the passenger car. In 1936 Daimler-Benz was one of the first companies to bring out a passenger car equipped with a diesel engine. Its 4-cyl, 4-stroke engine with a displacement of 2.6 liter delivered 45 bhp at a speed of 3500 rpm, which was considered remarkably high at that time. This first diesel-engine-powered passenger car was so well accepted that after World War II a special development program was started, which in the last few years has led to production diesel engines with a top speed of 4500 rpm.
1968-02-01
Technical Paper
680081
John H. Lienesch, Wallace R. Wade
Continuing Stirling engine development at General Motors has uncovered advantages of the powerplant never before fully appreciated. Smoke, odor, noise, and exhaust emission measurements indicate the attractiveness of the engine for applications in a “social” environment. Design details, particularly the external combustion system, are described here only in relation to low emission level. Measurements indicate that smoke and odor are practically undetectable. Sound measurements demonstrate the relative quietness of the engine. Additional data show that exhaust emissions, while very low, exhibit a strong dependence on burner design, air-fuel mixture ratio, burner inlet temperature, and exhaust recirculation.
1968-02-01
Technical Paper
680234
Charles D. Pratt
Air pollution caused by toxic fumes from the internal combustion engine is a concern to public health. The effects of the exhaust emissions, carbon monoxide, hydrocarbons, oxides of nitrogen, and aerosols on human beings are discussed, and caution is urged for proper ventilation of enclosed garage and industrial areas.
1968-02-01
Technical Paper
680242
Fred W. Bowditch
Since the late 1940's automotive engineers and scientists have been conducting research on emission control and developing the results into practical hardware for the four sources of emission from the automobile -- the crankcase, the exhaust, the carburetor, and the fuel tank. It is estimated that 20% of all hydrocarbon losses are divided between the carburetor and the fuel tank and, at present, there is no system available for controlling these losses. The exhaust accounts for 60% of the hydrocarbons and practically all the carbon monoxide. The remaining 20% of the hydrocarbons are emissions from the crankcase. Present control systems make substantial reductions in the emissions from these two sources. Under present levels of control there is a total reduction of about 60% in both total hydrocarbon and CO emissions. Another factor important to emission control is the need for proper maintenance.
1968-02-01
Technical Paper
680241
P. S. Myers, O. A. Uyehara
This paper reviews the source of the different emissions from an automobile. The exhaust is the major source of air pollution. This is composed of completely oxidized constituents such as H2O and CO2, both of which are considered harmless. Emphasis is placed on the partially oxidized components -- nitrogen oxide, carbon monoxide, and hydrocarbons -- as being the major pollutants. NO and CO are formed primarily in the bulk gases, whereas hydrocarbons are formed in the quench area. Discussed are several possible methods that could be considered in attempting to eliminate these pollutants. The authors are confident an answer will be found to this emission problem and that internal combustion engines will be used to power private vehicles rather than electricity.
1968-02-01
Technical Paper
680192
Werner Buttgereit, Christoph H. Voges, Christoph Schilter
The 1968 models of the VW 1600 sedan for the U. S. market are equipped with an electronically controlled fuel injection system. These vehicles comply with existing exhaust emission standards. Engine fuel requirements for constant operating conditions were determined by exhaust gas analysis. The test results furnished the basis for fuel metering by means of an electronic control unit. Deceleration fuel shutoff and closely controlled mixture enrichment for cold starting, warmup and full load ensure low emissions and good driving characteristics. Push-button checks for all the major circuit functions can be carried out with a special checking instrument.
1968-02-01
Technical Paper
680179
Richard S. Morse
The image of a large corporation in today’s technical world is, in many instances, dependent upon its interest in the innovative process and adaptability to change. Air pollution poses a serious threat to this country. In an effort to implement recommendations for the control of automotive air pollution, the more important findings of a government study group (fully reported in “The Automobile and Air Pollution: A Program for Progress”) are summarized. The development of effective means to infuse new ideas into the automotive industry is discussed.
1968-02-01
Technical Paper
680191
Jay A. Bolt
The automotive gasoline engine has been under heavy attack as a source of air pollution, and is now the subject of a very large program of research and development to reduce its undesirable vehicle emissions. The quantity of emissions that can reasonably be tolerated in different areas of the U.S. is presently unknown because of lack of information concerning air movements and air quality standards for man and plants. It is important that this information be made available as quickly as possible because the cost of emission controls of all types will rise rapidly. With rapidly rising costs for air pollution control from all sources, cost-value analyses are urgently needed for economy. Major reductions of the undesirable exhaust emissions of present powerplant systems have been made during the last few years and will continue to be accomplished, under the impetus of air pollution requirements and regulations.
1968-02-01
Technical Paper
680345
S. C. Fiorello
The Navy is engaged in programs to reduce the visible smoke emitted by gas turbine engines. These programs include the use of alternate fuels, the use of smoke suppressant fuel additives, and the use of combustor design technology. The current status in each of these areas is presented, as is a review of previous investigations. Tests of alternate fuels have shown that a significant but inadequate reduction of smoke was obtained. Of the fuel additives tested, one additive has shown superior performance to the others, and is suitable for use in certain engines. In order to determine the potential smoke reduction possible through combustor design, the combustion system of several engines is being redesigned. Some of the results of the redesign programs are discussed. Also presented is a brief description of the most commonly used methods of smoke measurement.
1968-02-01
Technical Paper
680347
T. Durrant
The main forms of atmospheric pollution by gas turbine exhaust are smoke and oxides of nitrogen at top speed and unburned fuel and carbon monoxide at engine idle conditions. Smoke trails constitute a visual nuisance and the other contaminants are either toxic or irritant or both. Combustor design with improvements in fuel air mixing and the use of air assisted sprayers will reduce smoke to barely visible levels on future engines. In addition, the latest annular chambers will give reduced concentrations of unburned fuel and carbon monoxide. Oxides of nitrogen will be difficult to reduce but current concentrations are less than measured on the automobile.
1968-02-01
Technical Paper
680348
J. J. Faitani
Results of experimental testing show that smoke can be significantly reduced by increasing the amount of air admitted to the primary zone. However, the location of the air entry ports, manner of air injection, and fuel spray quality are critical factors. Significant changes in combustor stability, ignition, carbon deposition, and durability characteristics are affected by the alteration of the primary zone fuel and airflow pattern. Extensive work has also been required to develop smoke measuring systems. A modified Von Brand Filtering Recorder has been selected as the standard measuring system.
1968-02-01
Technical Paper
680339
Seymour Hochheiser, Elroy R. Lozano
Pollution emissions due to jet aircraft operations at the major commercial airports in the New York Metropolitan Area were estimated. The impact on air pollution of the region was assessed. Pollutants considered in this report were: carbon monoxide, nitrogen oxides, hydrocarbons, aldehydes, and particulates.
1968-02-01
Technical Paper
680527
Shizuo Yagi, Kazuo Nakagawa, Akira Ishizuya, Yasuhito Sato
In the small displacement, high-speed, high-performance spark ignition engines being developed by Honda, the difficulties in reducing exhaust emissions without seriously impairing inherent engine characteristics are different from those encountered with the large displacement engines generally used in American cars. This paper reports on some of research in the following areas: 1. Development of a control device to minimize exhaust emissions during the frequent accelerations and decelerations in normal driving conditions. 2. Application of the air injection reactor system in small displacement engines. 3. The effect of “squish action” in a hemispherical combustion chamber on exhaust emissions. Through research and development, many of the difficulties were overcome and satisfactory results have been obtained in exhaust emission control under certain limited operating conditions.
1968-02-01
Technical Paper
680529
M. C. Baxter, G. W. Leek, P. E. Mizelle
A 1966 compact van, converted to operate on LP-gas and evaluated under the federal exhaust emissions procedure, approached several definitions of a “pollution-free vehicle.” Specific pollutant results were as follows: 1. The hydrocarbon and carbon monoxide levels of 126 ppm and 0.3%, respectively, were below the 1968 and 1970 emission limits. 2. Certain LP-gas fuel system designs promise to eliminate all evaporative losses. 3. The exhaust hydrocarbons were 70% less reactive than those in gasoline exhaust. 4. Aldehydes, a highly reactive class of exhaust compounds, were low. 5. Oxides of nitrogen were significantly higher with LP-gas because of operation at maximum economy mixtures and maximum power spark advance. 6. The use of a catalytic muffler and rich LP-gas mixtures produced very low oxides of nitrogen levels with other pollutants below the 1968 limits.
1968-02-01
Technical Paper
680528
W. F. Marshall, R. W. Hum
Smoke, odor, and other emissions of concern in environmental pollution from four diesel engines were studied experimentally; engine design, operational mode, and fuel characteristics were considered as variable factors influencing the emissions. The engine included a turbocharged 4-cycle unit, normally aspirated 4-cycle units, and an air-scavenged 2-cycle engine. All were direct injection, truck-type power units. Fuel characteristics differed widely among eight fuels used in the study, with principal differences occurring in sulfur and aromatic content. Results of the experimental study showed that emissions levels in all categories are markedly influenced by engine operation. Within the group of engines tested, generally high emissions of unburned hydrocarbon are associated with the 2-cycle design, high smoke levels with the 4-cycle normally aspirated engines, and high emissions of NOX and oxygenates with the turbocharged 4-cycle engine.
1968-02-01
Technical Paper
680443
Ralph C. Stahman, George D. Kittredge, Karl J. Springer
A program of research on diesel smoke and odor was sponsored by the U.S. Public Health Service by contract with Southwest Research Institute. A test facility was developed in which full-scale trucks and buses were operated on a chassis dynamometer through operating modes that yielded maximum exhaust smoke and odor. A system of exhaust dilution was employed to provide realistic odor concentrations to a panel of judges who rated the intensity and quality of the exhaust in terms of a set of chemical standards. Smoke levels were measured with a PHS-designed full-flow optical smokemeter. After an initial baseline evaluation of groups of buses and trucks with standard engines, various control techniques were evaluated to determine their effectiveness in reducing smoke and/or odor. Chemical analyses of the exhaust were made for the purpose of correlating the smoke and odor reductions with changes in exhaust composition.
1968-02-01
Technical Paper
680444
L. R. Reckner, R. E. Squires
A technique for measuring the intensity of diesel exhaust odor using a human panel has been developed and evaluated. While the ratings obtained are primarily useful for comparative tests, the degrees of difference which can be shown to be significant is sufficiently small to make the procedure adequate for practical use. The panelists were selected on the basis of superior olfactory ability and trained to rate the odor of diluted diesel exhaust against a series of 12 odor intensity standards contained in plastic bottles. The exhaust was diluted at the engine exhaust pipe and flowed dynamically through the presentation system in order to maintain its quality and intensity. The panelists were exposed to the diluted exhaust in a 1/2 cu ft sniff box for approximately 5 sec. The test programs of observations used were statistically designed. The resulting data were analyzed for significance of differences and confidence limits were determined.
1968-02-01
Technical Paper
680445
Gerald J. Barnes
Exhaust gas odor threshold dilution ratios were measured during idle operation of a single-cylinder 4-stroke cycle diesel engine using n-heptane as a fuel. Odor threshold dilution ratios were determined by a single panelist using a sample presentation termed the Sniff-Mask technique. The effect of various changes in the intake atmosphere composition on odor thresholds was determined. These composition changes fall into two general classes: 1. Substitution of the inert gases argon, helium, and carbon dioxide for the nitrogen contained in the normal intake air. 2. Addition of the inert gases argon, nitrogen, and carbon dioxide to the normal intake air. The substitutions of argon and helium produced a 15 fold reduction in the exhaust odor thresholds, while the substitution of carbon dioxide increased the odor threshold by a factor of 4. Directionally similar results were found for the addition experiments.
1968-02-01
Technical Paper
680463
C. G. Haupt
Exhaust emissions from a single shaft, nonregenerative, 90 hp gas turbine were measured at no load, two-thirds load, and full load operation on two fuels, regular kerosine and l% wt sulfur gas oil, and analyzed for sulfur dioxide, sulfur trioxide, nitrogen oxides (as NO2). unbumt hydrocarbons (hexane), aldehydes (formaldehyde), and exhaust solids. Additionally, the carbon monoxide content of the exhaust gases was continually monitored as an indication of possible changes in the engine combustion performance. This paper reports concentration levels of the various constitutents at varying engine loads for each of the two fuels.
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