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1971-02-01
Technical Paper
710842
Alden J. Pahnke, Wilfred E. Bettoney
The role of lead antiknocks in modern gasolines is discussed in terms of engine-fuel relationships. Exhaust emission characteristics of leaded and unleaded gasolines are compared in terms of both gaseous and particulate constituents. The effect of removing lead from gasoline on engine cleanliness, exhaust valve seat recession, octane requirements, and octane requirement increase is assessed. Extensive use is made of published information and some new information is presented. It is apparent that the use of lead antiknocks in gasoline produces effects on engine performance and exhaust emission characteristics which are both positive and negative in nature. Much more information is needed, particularly in terms of future vehicles equipped with advanced control systems, to determine the optimum fuel composition.
1971-02-01
Technical Paper
710844
Richard C. Schwing
In rich-exhaust manifold reactors, complete oxidation of carbon monoxide (CO) and hydrocarbons (HC), generally characterized by luminous conditions and high temperatures, is desirable. Some of the conditions necessary for luminous oxidation in an insulated exhaust reactor have been explored with a single-cylinder engine using both leaded and unleaded isooctane. Threshold-reactor air-injection rates required for luminous oxidation in the reactor were determined for engine air-fuel ratios (A/F) between 11.2 and 14.1. Leaded isooctane produced higher unburned HC concentrations in the exhaust than unleaded isooctane when injection air was introduced as well as when no air was added. In addition, oxidation of CO in the reactor was hindered in the tests with leaded isooctane. During one set of experiments, conditions were such that luminous oxidation in the reactor was achieved with the unleaded fuel, but was not achieved with the leaded fuel.
1971-02-01
Technical Paper
710843
Henry E. Leikkanen, E. W. Beckman
The use of lead compounds, when added to gasolines to enhance their antiknock properties, has resulted in more efficient combustion in high-compression engines, but their use has also caused lead deposits in the combustion chamber. To assess how lead antiknock compounds in gasolines influence combustion chamber deposits and exhaust emission levels, an intensive state-of-the-art review has been made, and data submitted by 18 different companies have been analyzed. These studies ranged in scope from single-cylinder engine investigations to a 122-car consumer test program. Based on this review, it was concluded that cars operated on leaded gasolines have higher equilibrium hydrocarbon emissions than those operated on unleaded gasolines, and that mileage accumulation conditions exert a major influence on the magnitude of the hydrocarbon net lead effect. The presence of lead in gasoline has no effect on carbon monoxide emission levels.
1971-02-01
Technical Paper
710074
C. M. Heinen
With the passage of the federal Clean Air Act, the automotive industry has a clear assignment to reduce automobile emissions drastically by 1975. The control devices presently available have already reduced hydrocarbons 83%, carbon monoxide 70%, and nitrogen oxides 33%. By 1975, these figures must be 98%, 97%, and 90%, respectively. This paper discusses the devices that have been developed to accomplish the reductions to date, and concludes that in the future the crankcase controls will require little change, that the evaporative controls will require some additional improvement but will not change substantially, and that engine modifications do not have much chance of meeting the 1975 standards without a great deal of supplementation. The author feels two methods are available which may be able to reach the 1975 standards: use of manifold reactors and use of catalysts. However, both present problems of materials and thermodynamics, due to high exhaust temperatures.
1971-02-01
Technical Paper
710072
H. Niki, A. Warnick, R. R. Lord
A method for the measurement of nitric oxide (NO) in photochemical smog research was developed using the chemiluminescence from the rapid reaction between ozone (O3) and NO. An instrument based on this method has been constructed; it is applicable to a number of automotive problems. This NO detector has been tested extensively in both laboratory and dynamometer experiments, and has been shown to have several outstanding features: detection sensitivity of 0.01-5000 ppm, selective detection for NO, continuous monitoring with fast response time, and good stability and ease of operation. Examples of results obtained in turbine experiments and in vehicle exhaust analysis are presented.
1971-02-01
Technical Paper
710075
C. E. Moser
The Coordinating Research Council research program on vehicle emissions consists of some thirty projects with a three-year projected cost of more than $ 10 million. The functional Air Pollution Research Advisory Committee and the Project Manager oversee these studies, encompassing the fields of engineering, atmospheric chemistry, and medicine. Results are being utilized by industry and government to reduce the level of emissions now contaminating the atmosphere.
1971-02-01
Technical Paper
710069
G. W. Niepoth, G. P. Ransom, J. H. Currie
An exhaust emission control system has been developed for used cars of the 1955-1967 model years. Average exhaust emissions were reduced on 194 cars by 53% HC, 33% CO, and 31% NOx. The package consists of increased idle speed, leaner idle mixture, and retarded ignition timing. A thermostatic vacuum switch provides engine cooling protection with the retarded ignition. For maximum effectiveness of the control, the engine must be in good running condition.
1971-02-01
Technical Paper
710070
Joseph M. Gall, David A. Olds
An automotive tune-up clinic for the purpose of reducing undesirable exhaust emissions was held March 14, 1970, as part of an environmental teach-in. The event was sponsored by the student branch of SAE at the University of Michigan. The results of this event clearly show that improper automotive maintenance can be a major factor in atmospheric pollution. It was found that idle hydrocarbon emissions were reduced by an average of 55% with a tune-up in which the idle mixture ratio and speed were adjusted for minimum carbon monoxide emissions. Our conclusion is that the individual motorist must begin to develop an attitude of responsibility toward the maintenance of his automobile to ensure low emissions.
1971-02-01
Technical Paper
710071
Marian F. Chew
Maintenance programs indicate that exhaust emission controlled cars with hydrocarbon (HC) emissions above 400 ppm or carbon monoxide (CO) above 2.25% will have emissions reduced by proper maintenance. Distribution curves of recent surveillance data show that one-third of the 1966-1969 cars have emissions above these assured reduction levels. Calculations show that maintenance based on reducing high emitters of HC and CO should reduce total HC by 19%, CO by 30%, but increase oxides of nitrogen (NOx) by 9%. Further calculations show that maintenance based on reducing high emitters of HC, CO, and NOx should reduce total HC by 20%, CO by 25%, and NOx by 6%. The inclusion of NOx testing along with HC and CO in the idle inspection test method is nearly as effective in identifying high emitters of HC, CO, and NOx as the longer seven-mode test method.
1971-02-01
Technical Paper
710062
Walter J. Weber,
Complex problems of maintaining environmental quality are closely associated with technologic expansion and growth; prime among these are the problems of water pollution and a degraded water resource. The intent of this discussion is to provide a reasonably comprehensive overview of water pollution and abatement measures in the industrialized United States, with some insight to public and private attitudes and policies with respect to pollution.
1971-02-01
Technical Paper
710060
John T. Middleton
This paper outlines the provisions of the 1970 Clean Air Act and the steps that must be taken by the federal government, state and local governments, industry, and the public to implement its provisions. The basis of the standards to be issued under the Act is the need to protect the public health and welfare. The need to attain them will either force the use of available technology or create new pressures for the discovery and demonstration of new methods to control air pollution. The federal government will set the goals, it will be up to the state and local administration, planners, and technicians to find ways to meet them. The effects of this at all levels of government is outlined. The automobile is the source of about half of the air pollution in the United States. Therefore, the automobile is the principal target of the Clean Air Act. This may well press the internal combustion engine to its design limits and require new approaches by industry and its engineers.
1971-02-01
Technical Paper
710004
Richard E. Marland
The destruction of our environment by pollution is now everyone's concern, and the automobile run on fossil fuel is recognized as a principal source of pollution. The need for adequate public transportation emphasized by the death, disease, destruction of life and natural resources, and contribution to the waste problem wrought by the increasing numbers of private automobiles on our highways and city streets is balanced against the individual's need for privacy, which is at least partially fulfilled by operating his own automobile. Smaller, safer, nonpolluting cars must be designed and made available and a safe, efficient system of public transportation must be constructed, in order to ensure that the quality of life deteriorates no further than it already has.
1971-02-01
Technical Paper
710006
Gerhard Reethof
The increasing levels of affluence in the highly industrialized western societies have resulted in a drastic and increasing deterioration of the quality of man's environment. The economic facts in these societies are such that it actually “pays to pollute.” Air and water pollution, solid waste disposal, and noise pollution have become areas of major concern for the institutions of higher learning. Through instruction and research, knowledge toward the alleviation and control of environmental pollution must be disseminated and advanced. One of the major contributors to the present state of environmental deterioration is the almost absolute lack of well-defined control criteria. Much needs to be done in this area and the academic community has the know-how and economic remoteness to tackle this problem. One of the most fascinating facets of the environmental pollution problem is its interdisciplinary nature.
1971-02-01
Technical Paper
710005
J. G. G. Hempson, M. H. Howarth
Introducing the direct study of environmental problems into university courses seems too difficult. The only practical way of alerting future engineers to their responsibility in considering the effect of their activities on the environment is indirectly. The development of courses in instrumentation and the use of experimental equipment are effective and do not require substantial modification of an engineering cirriculum. The intention of this paper is to describe certain experimental work to illustrate their use in the field of environmental problems.
1971-02-01
Technical Paper
710012
R. D. Fleming, D. B. Eccleston
A single-cylinder research engine was operated on pure hydrocarbons (HC) and simple mixtures of pure hydrocarbons to study the effect of fuel composition, equivalence ratio, and mixture temperature on exhaust emissions. Used as fuel components were hydrocarbons-n-pentane, 2-methyl-2-butene, isooctane, and m-xylene. Total hydrocarbon emission in terms of moles of exhaust HC/mole of fuel input was lowered by increasing the amount of xylene in the fuel when operating on the fuel-rich side of stoichiometric; total hydrocarbon emission was higher for higher aromatic fuels when air-fuel ratios approached the lean misfire limit; the effect of mixture temperature on hydrocarbon emission was insignificant. 1-Methyl-3-ethylbenzene was observed as a synthesis product of combustion in the exhaust from fuels containing m-xylene. With increasing m-xylene concentration in the fuel, the yield of 1-methyl-3-ethylbenzene increases, reaches a maximum, and then decreases.
1971-02-01
Technical Paper
710013
G. S. Musser, J. A. Wilson, R.G. Hyland, H.A. Ashby
Exhaust gas recirculation (EGR) was found to be an effective means of reducing automotive NOx levels with no major unsolvable problems over 52,000 miles under city/suburban driving conditions. Compatible with air injection and engine modification systems for HC and CO control, EGR effectively reduced the NOx levels with no decrease in reduction over the 52,000 miles. Engine wear and engine cleanliness with EGR was normal for the mileage and driving regime. However, the throttle area and exhaust valves were found to be sensitive to leaded fuels.
1971-02-01
Technical Paper
710014
L. S. Bernstein, K. K. Kearby, A. K. S. Raman, J. Vardi, E. E. Wigg
Nickel-copper alloys, marketed under the name Monel, have been found to be extremely active NOx reduction catalysts. At temperatures above 1300 F, and under net reducing conditions, Monel will catalyze the removal of 90% or more of the NO in automotive exhaust at space velocities of up to 100,000 v/v/hr. On unleaded fuel, Monel catalysts have shown good activity maintenance in mileage accumulation runs as long as 31,000 miles. Catalyst life is limited by physical deterioration of the catalyst which causes increases in exhaust back pressure. On unleaded fuel, Monel in its present form will last approximately 10,000 miles at 1700 F (∼60 mph) before back pressure begins to rise rapidly. The presence of lead in the fuel substantially increases the rate of Monel deterioration. When Monel is used as part of a dual-bed catalyst system two problems, which appear to be generic to dual-bed catalyst systems, arise.
1971-02-01
Technical Paper
710007
Kenneth W. Ragland
While it is recognized that man's technological demands are degrading the earth's biosphere, there is little agreement on what to do about it. What part has engineering played in all this? How can engineers contribute to the solution of ecological problems? Is the answer an “ecological ethic” and if so, how can it be developed? A discussion of these dilemmas and the role the university can play in developing educational programs involving both the natural and life sciences to establish an ecological ethic and help resolve some of the major environmental problems, is presented. The paper also explores how these programs can be made part of an engineer's education.
1971-02-01
Technical Paper
710008
J. D. Benson, R. F. Stebar
The effects of charge dilution on the exhaust emission of nitric oxide (NO) from a single-cylinder engine were evaluated over a range of engine design and operating parameters. Nitric oxide emission decreased as much as 70% as charge dilution fraction (volume fraction of product gases in the combustion chamber prior to ignition) was increased from 0.065 to 0.164 due to increased valve overlap, external exhaust recirculation, and reduced compression ratio. With these three variables, NO emission was strongly dependent on charge dilution fraction, but was independent of the specific method used to change charge dilution. Other variables such as valve overlap position, spark timing, and exhaust pressure also affected charge dilution and NO emission, but the relationship between charge dilution fraction and NO emission for these variables was not consistent.
1971-02-01
Technical Paper
710009
Ather A. Quader
This study was undertaken to develop a better understanding of how intake charge dilution by various gases affected nitric oxide (NO) emission from a single-cylinder spark ignition engine. Carbon dioxide, nitrogen, helium, argon, steam, and exhaust gas were individually added to the intake charge of a propane-fueled, single-cylinder engine operated at constant speed and load. Nitric oxide emission was reduced in all cases. The gases with higher specific heats gave larger NO reductions. The product of diluent flow rate and specific heat correlated with NO reduction. The effects of diluents on calculated combustion temperature, mbt spark timing, and fuel consumption are also presented and discussed.
1971-02-01
Technical Paper
710010
S. Ohigashi, H. Kuroda, Y. Nakajima, Y. Hayashi, K. Sugihara
Earlier work has demonstrated that exhaust gas recirculation (EGR) decreases peak combustion temperature and thus reduces the concentration of nitrogen oxides (NOx) in spark ignition engine exhaust. The present authors hypothesized that NOx formation is primarily affected by the heat capacity of the combustion gases and recycled exhaust. The hypothesis was tested in an experimental program involving the admission of inert gases such as He, Ar, H2, and CO2, and water in place of EGR. In addition to confirming the validity of the original hypothesis, the test data also indicated that engine output and efficiency were significantly affected by the heat capacity of the combustion gases. The authors conclude that EGR functions by increasing the heat capacity of the working fluid, and demonstrates that the correlative changes in NOx and engine performance can be predicted from heat capacity considerations.
1971-02-01
Technical Paper
710508
James F. Arndt
Over the past 50 years, an estimated 30,000 tractor operators have been accidentally crushed under their overturned vehicles. During that time, stability, preventive devices, and education have been tried to reduce the number of such accidents. Within the past 15 years, worldwide activity has been concentrated on developing adequate roll-over protective structures (ROPS) for operator protection. In order to measure the adequacy of the structures, various worldwide performance standards have been created. The latest include those of the SAE, which recognizes the need for a ROPS to absorb energy in order to minimize injury to the operator.
1971-02-01
Technical Paper
710428
John Stockham, Howard Betz
The objective of this study was to relate the visibility of inflight jet exhaust to the AIA smoke number. A method based on photographic photometry was developed for measuring the optical density of smoke plumes. This method was related to visibility and to the smoke number through transmissometer measurements and visibility theory. A portable transmissometer, capable of operating over a wide range of optical path lengths and under varying ambient light conditions, was fabricated for use on this study. The mathematical expression relating the transmission measurements to the smoke number was derived. Liminal visibility requirements of smoke trails, developed from light scattering theory, correlated with actual visual observations and the transmissometer and photometry measurements. Test results, with the engines investigated, indicate that AIA smoke numbers below 23 were associated with invisible exhaust plumes.
1971-02-01
Technical Paper
710429
Eloy R. Lozano, Ralph E. George
A summary is presented of the results of a comprehensive air pollution study conducted by the Los Angeles County Air Pollution Control District (LACAPCD) under contract with the Air Pollution Control Office of the Environmental Protection Agency. Included in the data obtained are the results of exhaust testing, emission estimates of aircraft and airport ground operations, measurements of the atmosphere in the immediate environs of the airport, and passenger cabin measurements. The data indicate that the CO emissions from airport ground operations exceed levels generally attributed to commercial jet aircraft. Passenger cabin CO measurements during startup and taxiing procedures indicate average levels of 2-7 ppm. Air quality levels in the residential areas around the airport indicate average 6 hr CO concentrations of 3-11 ppm.
1971-02-01
Technical Paper
710413
Clyde W. Pace
This paper provides information on the Airport Certification Program, including the certification/safety inspection procedures and a list of minimum safety standards that will be contained in the Federal Aviation Regulations (FAR). Any additions or modifications to the minimum safety standards will be updated by the author at the May 10, 1972 SAE Meeting.
1971-02-01
Technical Paper
710404
Arnold E. Anderjaska
Fatigue substantiation of wing structure on small airplanes is now required by the Federal Aviation Regulations for civil type certification of new designs. Methods for substantiation of this structure under the “safe-life” concept, including suggested loading spectra and procedures for strength determination are outlined. The background leading to these methods and a basis for establishing scatter factors are presented. Procedures for substantiation under the “fail-safe” concept are also given.
1971-02-01
Technical Paper
710403
R. D. Christian
A Project Group of representatives of General Aviation Manufacturers Association (GAMA) companies was established and given the assignment to study several methods of fatigue evaluation and recommend procedures for compliance with new FAA regulations concerning fatigue of aircraft wings. The group held several meetings in which sources of data and the major problems associated with fatigue evaluation were discussed. The author served as chairman of the Project Group and reports in this paper on the studies and recommendations made by the group.
1971-02-01
Technical Paper
710370
W. C. Zegel, A. F. Souza, L. R. Reckner
The purpose of this study was to evaluate exhaust emissions of representative aircraft as they were flown in a normal manner. At the same time, the extent of afterburning was measured by sampling the exhaust plume downstream of the exhaust stack and comparing the plume composition, corrected for dilution, to the composition of the stack gases. Exhaust emissions from nine light aircraft were determined, using a nine-mode takeoff-cruise-landing (TCL) cycle developed for this study. Exhaust component concentrations and fuel consumption rates were measured for each mode during ten test flights per aircraft. Pollutant concentrations were converted to emission rates per pound of fuel, per minute, per mode, per TCL cycle, and per landing-takeoff (LTO) cycle.
1971-02-01
Technical Paper
710364
S. S. Sorem
Possibilities for the reduction of automobile emissions by changes in gasoline composition have been reviewed. Small benefits are achievable by limiting front end volatility and light olefin content. California has already passed legislation which places limits on these fuel properties. Fuel hydrocarbon type, octane number, and lead antiknock content are interrelated. Maintenance of octane number while removing lead can be achieved by increasing the fuels aromatic content with a resulting increase in some aspects of the exhaust's reactivity. Alternatively, lead may be removed without changing hydrocarbon composition if the engines octane number requirement is reduced. These changes may result in lower exhaust hydrocarbon content. They will result in lower engine efficiency and hence higher exhaust flow rates. The net effect on pollutant emissions is in doubt. Gasoline additives, other than lead, make little direct contribution to the pollutant content of exhaust.
1971-02-01
Technical Paper
710362
C. G. A. Rosen
The widely recognized necessity for substantially reducing air pollution caused by the automotive powerplant before the end of the century has, led to much experimentation. Both government and industry must bear the responsibility for improving the engine itself and the fuel it consumes. Promising alternatives to present vehicles include a gas turbine engine with regenerator, a hybrid engine combining a low-powered, fuel-burning engine with electric batteries. New fuels-the currently available low-lead and no-lead gasolines, natural gas and liquid propane gas, dual fuel systems, and even fuel cells-are also being investigated. Cars incorporating the eventual solution, closed-loop systems, should be available by the year 2000.
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