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1984-01-01
Technical Paper
845113
Rathindra Dutta
Up to now it was necessary that with the exhaust gas measuring the recall of the tests (ECE, CVS, Japan etc.) was coordinated by a master computer who collected the data, processed them and recorded them via the peripheral equipment or that an operator undertook these functions. In a modern processing system the control and evaluation expense in the central computer is reduced by the reasonable application of microprocessors in the different decentralized units such as analysing systems, CVS-systems, driver's aid and so on. For this purpose in the individual units are executed independently in the following operations: - sequence control - independent execution of calibrations - automatic switching over of the measuring range - conversion of the measuring values into physical values - linearization Specified interfaces and standardized transmission software facilitate the interplay of the units with a master computer.
1984-01-01
Technical Paper
845083
Leopold Mikulíc, Hans Peter Lenz
The purpose of the study reported here was to investigate the applicability of monolithic honycomb catalysts for exhaust gas purification on small two-stroke engines. Investigations were carried out to assess the relations between operating conditions and the catalysts' CO- and HC converstion efficiency and to optimize conversion efficiency under stationary and transient engine operating modes. Furthermore, the influence of a catalyst on smoke emission was investigated as were the aging characteristics of various catalysts under European operating conditions with the engine running on leaded fuel
1984-01-01
Technical Paper
845084
W. Dietrich, O. Hiemesch, G. Langeloth
Supported by the Federal Office of the Environment, tests aiming at a drastic reduction in pollutants by means of a subsequent exhaust-gas treatment have been carried out at MWM's with a G 234 spark-ignition engine running on natural gas. The tests revealed that the use of three-way catalysts on engines with a cylinder displacement of 1.8 dm3 involves particular requirements to be met by the lambda control system. These could not be fulfilled by altered solutions prevailing on the market in which the air/fuel ratio is oscillating around the catalyst optimum value. Consequently, MWM developed an electronic lambda control system using the voltage of the lambda sensor directly as the controlled variable for the air/fuel ratio of the engine. The maximum conversion rates achieved at constant engine speed of n = 1500 rpm amounted to: NOx = 99% CO = 98% HC = 70%.
1984-01-01
Technical Paper
845068
H. P. Willumeit, P. Steinberg, B. Scheibner, W. Lee
Calculating heat balance of Otto engines, one can recognize that the ratio between heat transfer and power increases in the part load range, i.e. city driving. To improve the efficiency of such engines it is necessary to reduce the quantity of heat transfer and also of friction losses. Both effects can be achieved by increasing the temperatures of the cooling medium and the lubricant. This leads to two effects: - reduction of fuel consumption - reduction of exhaust emissions. Both effects are valid even in the warming-up-phase as well as under normal operating temperature and are confirmed by the results of our experiments.
1984-01-01
Technical Paper
845072
U. Seiffert, H. Oetting, P. Walzer
In the last 12 years, the emission constituents limited in the ECE-regulations have been reduced by as much as 50%, at the same time the fuel consumption has been reduced by more than 20%. In some European countries the introduction of unleaded gasoline and the tightening of the pollutant emission legislation is now being discussed. The technology of the 3-way-catalyst used in the USA attains the lowest pollutant emission level, leads, however, to higher fuel consumption and additional production costs. In addition, this technology is not compatible with the different gasoline lead contents used in Europe. Exhaust gas recirculation systems with and without oxidation catalysts or lean mixture concepts with homogenious and nonhomogenious mixture formation are being discussed as alternative concepts for controlling pollutant emissions.
1984-01-01
Technical Paper
845078
S. S. Lestz, S. M. Geyer, M. J. Jacobus
Results comparing fuel efficiency, pressure development history, gas phase emissions, and particulate biological activity for several nonpetroleum-based fuels with a standard number two Diesel fuel oil baseline are presented. In addition, a correlation based on ignition delay is presented which appears to more reliably reflect the combustion performance for these nonpetroleum fuels than does the cetane index. In this single-cylinder engine study, it was found that none of the fuels investigated showed a marked difference in fuel efficiency when compared to Diesel fuel oil. The same was not generally true for the exhaust emissions, where differences were found in the gas-phase as well as the particulate emissions. Most notable were the changes in the oxides of nitrogen and in the particulate generation rates. The oxides of nitrogen were fuel dependent as was the mass rate of particulate production and its soluble organic fraction.
1984-01-01
Technical Paper
845079
F. Anisits, G. Schwarzbauer, H. Kratochwill
With the introduction of tougher emission regulations, the diesel engine reaches long-term its limit for the use in passenger cars, without the further development of emission regulation systems. Starting from the current state of technology, various problems and their associated solutions with the development involved are discussed. These solutions should enable the leading position of the diesel engine as the most economical prime mover of passenger automobiles to be continued.
1984-01-01
Technical Paper
845082
U. Heinrich, W. Stöber, H. Klingenberg
The effects of the total exhaust emission with its hundreds of different compounds and potential coergisms resulting therefrom, with special reference to a potential carcinogenic or cocarcinogenic effect on the respiratory tract, can only be established using experiments which consider the exhaust with all its gaseous components and particulate matter as a whole. Long-term diesel and gasoline engine exhaust inhalatin studies with rats, hamsters and mice which have already been accomplished or are still running at the Fraunhofer-Institut für Toxikologie und Aerosolforschung, aim to investigate the chronic-toxic effects, as well as the potential carcinogencity or cocarcinogenicity of exhaust emissions.
1984-01-01
Technical Paper
845081
H. Waldeyer, D. Hassel, P. Jost, F. Dursbeck
A procedure to determine the exhaust gas emission factors for the fleet of heavy duty vehicles in the Federal Republic of Germany is reported on. The exhaust gas emission factors for carbon monoxide, unburned hydrocarbons, nitrogen oxides and fuel consumption are indicated separately for light commercial vehicles (maximum permissible weight not exceeding 3.5 t) and heavy duty vehicles (maximum permisible weight exceeding 3.5 t). With the particle emission factors, a distinction was made beteen the total particle mass (carbon + associated organic substances) and particle mass free of hydrocarbons. As for the heavy duty vehicles, appreciable differences were observed in the partial emission factors of the various mass classes. The application of the procedure thus requires that the frequency distribution of the mass classes is known.
1984-01-01
Technical Paper
845025
K. Subba Reddi, H. B. Mathur, M. K. Gajendra Babu
1984-01-01
Technical Paper
845010
F. X. Moser, H. Grabner, A. Nefischer
By applying large top land gaps bore polishing can be reduced significantly or avoided entirely. Lube oil consumption is also reduced and remains constant over a long period of time. By means of a suitable lay out of the piston and a minimizing of the air volume in the top land gap, the fuel consumption can even be reduced somewhat versus the standard piston version. With a minor correction of the fuel injection timing the same U.S. 13-mode-cycle emission values of HC and NOx as with the standard piston can be obtained without any deterioration of the fuel consumption versus the standard version.
1984-01-01
Technical Paper
845040
M. L. Monaghan
/SUMMARY A description of the main features and current status of the CDI, Controlled Direct Injection System is given. A 2.5l turbocharged CDI engine is compared with its production IDI equivalent by means of vehicle tests. The vehicles, identical saloon cars, were compared on an as-installed basis and, as nearly as possible, on an equal performance basis. Results are presented covering fuel consumption and emissions with European and U.S. fuels over a number of different driving cycles. Drive-by, idle and internal noise levels were recorded. Starting tests were carried out to compare starting, smoke at start and cold idle. An analysis of the cost differences between the CDI and its IDI equivalent is presented.
1984-01-01
Technical Paper
845038
C. Bassoli, G. Bodritti, G. M. Cornetti
In direct injection Diesel engines having a unit displacement less than 1 liter, the use of high compression ratios (19\20 instead of 16\17) is mandatory for solving cold smoke problems and reducing HC\NOx emissions. The increase of compression ratio however is associated to the increase of black smoke and specific fuel consumption. On the basis of systematic measurements of the main combustion quantities and 2-D computations of the air motion and spray development inside the cylinder, a re-entrant high compression ratio chamber was defined. Experimental results in terms of fuel consumption, black smoke and gaseous emissions are presented. The optimum squish-to-swirl ratio is discussed.
1984-01-01
Technical Paper
845043
A. Theiss, H. Baumgartner
Mechanical supercharging in combination with an expansion operation of the charger in part load range of the engine has proven to be an efficient method to reduce fuel consumption with simultaneous reduction of pollution. By reducing swept volume and maximal speed when compared to a naturally aspirated engine of similar power the operating conditions of the engine during driving may be shifted generally into ranges of more favourable specific fuel consumption. In a configuration particularly advantageous for application on Otto engines the charger is provided with a variable inlet control edge by means of which the charge of the engine during part load is influenced. The throttle loss of the engine is at least partly utilized as positive technical energy via the charger which is operating in this range as an expansion machine. The cooling of the inlet air due to the energy absorption results is a reduction of NOx emissions with simultaneous decrease of hydrocarbon emission.
1983-11-07
Technical Paper
830946
Raymond H. Bartlett
Road transport in Australia is regulated by separate Governments in six States and two Territories resulting in differing standards of regulation. A co-operative effort by Federal and State Governments to achieve uniform regulation of vehicle safety and emissions has improved the situation. This paper reviews the development of the regulatory system and possible changes to both the system and regulations.
1983-10-31
Technical Paper
831737
Nicholas P. Cernansky, Richard S. Cohen, Prasad R. Tumati
As a group of diesel engine exhaust products, oxygenates have been found primarily responsible for the characteristic exhaust odor. In diesel combustion systems, it is thought that oxygenates are produced in too-lean-to-burn regions and are subsequently destroyed in the high temperature flame regions. In order to study these destruction processes, n-dodecane/oxygen/inert gas mixtures have been burned in a high temperature premixed, prevaporized, one-dimensional, laminar flat flame burner. The rate of decay of oxygenates along the axis of the burner in the reaction zone and in the post flame zone has been measured and followed. An empirical relationship describing the rate of decay of oxygenates as rate = −k(T) [oxygenates]a[O2]b has been derived. The reaction orders, a and b, have been found to be 0.91 ± 0.06 and 1.44 ± 0.05, respectively. The rate constant has Arrhenius parameters E = 23.95 ± 5.77 kcal/mol and log10 A = 10.98 ± 1.56, where the units for A are discussed in the text.
1983-10-31
Technical Paper
831736
Stephen P. Bergin
This paper reports on the relative contributions of diesel fuel aromatic content and 90 percent distillation temperature to particulate exhaust emissions (both carbon and hydrocarbon) from a single-cylinder, indirect-injection, light-duty diesel engine as a function of engine load. The carbon and hydrocarbon fractions of particulates were determined by using a vacuum oven to heat filters on which particulates had been collected. As expected, multiple linear regression analysis showed that the carbon particulate emission index (grams of particulates emitted per kilogram of fuel consumed) correlated well with a combination of aromatic carbon content and 90 percent distilled temperature of the eight fuels at all six loads tested. A new finding is that the relative contributions of these two fuel properties to the carbon particulate emission index depended strongly upon engine load (overall equivalence ratio).
1983-10-31
Technical Paper
831724
Colin R. Ferguson, Milt Chapman, Hirofumi Kizawa, Robin F. Nash
Instantaneous opacity measurements have been made for gases in the exhaust port and one meter downstream. The results obtained showed the opacity to be time independent, of negligible variation from cycle to cycle except near the smoke limit and an order of magnitude greater at the port than one meter downstream. Results are compared with gas sampling measurements of the particulates.
1983-10-31
Technical Paper
831713
Christopher Weaver
Current U.S Environmental regulations will limit particulate emissions by light duty diesel automobiles and trucks to 0.2 and 0.26 grams per mile respectively, beginning in 1987. Barring some breakthrough, attainment of these emissions levels will require the use of trap-oxidizers on all but the smallest vehicles. This paper reviews the present state of the art in trap-oxidizer technology and examines the requirements which a trap-oxidizer system would have to meet in order to be installed and marketed in production vehicles. The tasks remaining to be accomplished in the development of commercially feasible trap-oxidizer systems are briefly discussed. It is concluded that trap technology is quite advanced, with at least two apparently feasible types of particulate traps now available. The remaining tasks in developing a commercial trap-oxidizer system involve the development of improved trap regeneration systems and the development of automatic controls for the regeneration process.
1983-10-31
Technical Paper
831712
Bruce B. Bykowski, Charles T. Hare, Robert L. Mason, Thomas M. Baines
Exhaust emission data from several fuel effects studies were normalized and subjected to statistical analyses. The goal of this work was to determine whether emission effects of property variation in alternate-source fuels were similar, less pronounced, or more pronounced than the effects of property variation in petroleum fuels. A literature search was conducted, reviewing hundreds of studies and finally selecting nine which dealt with fuel property effects on emissions. From these studies, 15 test cases were reported. Due to the wide variety of vehicles, fuels, test cycles, and measurement techniques used in the studies, a method to relate them all in terms of general trends was developed. Statistics and methods used included bivariate correlation coefficients, regression analysis, scattergrams and goodness-of-fit determinations.
1983-10-31
Technical Paper
831711
J. Scott MacDonald
An experimental study was conducted to characterize the aerosol that passes through a wall-flow monolith trap and to determine how the trap performance varies with engine operating condition. Steady-state experiments conducted with a 5.7-L diesel engine operating at several test conditions showed that the wall-flow trap collected nearly all of the carbonaceous particulate material, regardless of the operating condition. However, the ability of the trap to collect the volatile particulate material was dependent upon the exhaust gas temperature. Particle size measurements showed that significant concentrations of small, nuclei-mode particles exist downstream of the filter at some engine operating conditions. The quantity of nuclei-mode particles was shown to be dependent primarily upon exhaust gas temperature. Without the exhaust filter, the concentration of these small particles was generally negligible.
1983-10-31
Technical Paper
831754
Kurt Falk
Motor and Oil industries in Europe continue to recongnize the need to establish realistic test procedures to evaluate the driveability performance of cars and fuels. Accordingly, representatives from both industries have been working together in the CF24 Group, formed in 1978 under the auspices of the Coordinating European Council (CEC), to develop standard driveability test methods. While CF24's tasks and preliminary achievements were first outlined to the SAE in 1981, this paper describes the Group's more recent field test in Sweden and chassis dynamometer work throughout Europe, which has led tho the establishment of a European cold weather driveability test procedure. The method provides a means of assessing engine starting, idling, and drive quality during the warm-up phase, and is capable of distinguishing between fuel volatility, vehicle design characteristic, and ambient air temperature effects.
1983-10-31
Technical Paper
831755
J. K. Pearson, P. L. Or man, B. D. Caddock
Vehicle driveability is a function of gasoline volatility, ambient conditions and engine design. The ability to predict driveability performance from a knowledge of fuel/air mixture temperatures and gasoline properties would greatly assist both fuel and engine development. Accordingly, a model to predict engine hesitation under full-throttle accelerations (a major driveabilty malfunction) has been developed. Hesitation occurs when the fuel/air mixture reaching the combustion chambers is too lean to burn. Thus the model is based on the calculation of heat flow and air/fuel vapour ratios in the engine inlet manifold. Chassis dynamometer tests for two different cars using a range of fuels and a range of test temperatures have shown that the model gives an accurate prediction of mixture temperatures and engine hesitation under full-throttle conditions.
1983-10-31
Technical Paper
831751
Richard Steinke, Joachim Bosse, Max Gairing, Heribert Nasch, John Richardson
Abstract The lubricant technical community in Europe (including the U.K.) has been developing a series of performance standards for lubricants resembling the API/ASTM/SAE tripartite system, but directed towards European needs. Whilst considerable use is made of the API categories such as SE, SF, CD, etc., there are nevertheless several areas where it is felt that the U.S. specifications do not fully address European needs. Because of this the European engine manufacturers under the aegis of the CCMC are developing a proposed set of gasoline and diesel engine test sequences oriented towards the European needs. This paper is only concerned with those in the diesel area. Also, individual engine manufacturers have their own specifications in advance of the adoption of a common European specification. Those tests which European engine manufacturers are considering highlight the difference between Europe and the U.S..
1983-10-31
Technical Paper
831676
James G. Matson, L. William Huellmantel
Engine and chassis dynamometer tests were conducted using the GMR GT-225 experimental automotive gas turbine engine to determine the effect of fuel nitrogen on NOx emissions. Kerosene doped with pyridine was used as fuel and both a conventional diffusion-flame combustor and an experimental lean, premixing-prevaporizing combustor were tested. The results show that a sizable amount of fuel nitrogen is converted to NOx with both combustors. The lean, premixing-prevaporizing combustor converted a greater fraction of the fuel nitrogen than did the diffusion-flame combustor and for both combustors, the fraction converted decreased as the fuel nitrogen content increased.
1983-10-31
Technical Paper
831675
Alex R. Sapre, Ather A. Quader
Nitrogen-free and nitrogen-doped fuels were investigated using a single-cylinder, spark-ignition engine, and gasoline and diesel-powered vehicles. The single-cylinder engine experiments showed that only NO (nitric oxide) emissions were affected by nitrogen in the fuel and that the percentage of fuel nitrogen converted to NO (PNCNO) ranged from about 5 to 100. Generally, PNCNO increased when equivalence ratio, concentration of nitrogen in the fuel, engine load, or compression ratio decreased; PNCNO also increased as the level of EGR or engine speed increased, or as spark timing was retarded from MBT. The vehicle experiments showed PNCNO to be substantially higher (∼80-90) in gasoline engines than in a diesel engine (∼35), and that equivalence ratio, fuel-nitrogen concentration and EGR affected PNCNO in a multi-cylinder gasoline engine in the same manner as in the single-cylinder engine.
1983-10-31
Technical Paper
831710
James P. Myers
Time-resolved sampling was used to measure hydrocarbon concentration profiles in the exhaust of a small, high-speed, direct-injection diesel engine in an effort to determine significant sources of hydrocarbon emissions. The engine was a single-cylinder design with a 0.53-L displacement and a swirl-supported, high-pressure-injection combustion system. In the past, most sampling work performed on diesel engines has been done in the cylinder and has focused on either oxides of nitrogen or soot emissions. The exhaust sampling done in this study provided a simple yet informative means of studying hydrocarbon emissions. Results from this study for wide ranges of engine speed and air-fuel ratio showed a single peak in the hydrocarbon concentration profile as a function of crank angle. Phasing of the hydrocarbon concentration peak generally coincided with the blowdown period of the exhaust event.
1983-10-31
Technical Paper
831698
Thomas C. Austin, Gary S. Rubenstein, Leonard D. Verrelli, Thomas E. Moyer
Recent tests conducted by the Alaska Department of Environmental Conservation and low ambient temperature tests previously conducted by a variety of other organizations indicate that less progress is being achieved in the control of emissions during cold weather than under temperatures similar to those used during EPA certification testing. Although CO emission standards dropped from 15 grams per mile to 7 grams per mile between 1975 and 1981, far less of a change occurred in CO emissions from new vehicles at 20°F. Cold start CO emissions at 20°F are about 60 grams per mile for late model cars at low mileages. The available test data on these cars seem to indicate that results achieved using the standard emission test procedure are poorly correlated with emissions at lower temperatures. However, the low temperature CO emissions of cars certified at 3.4 grams per mile CO are nearly 502 lower than vehicles certified to a standard of 15 grams per mile.
1983-10-31
Technical Paper
831699
Jerry Gallagher, Michael J. O'Toole, Melvyn C. Branch
Automobiles and other mobile sources are a major contributor to precursors of ozone and to carbon monoxide in urban area air pollution inventories. In a typical urban area, over fifty (50) percent of the emissions of hydrocarbons (HC) and of oxides of nitrogen (NOx), which react in the presence of sunlight to form ozone, are derived from vehicular sources. Over ninety (90) percent of the carbon monoxide emissions in these areas are also attributable to mobile sources. This problem is accentuated in the Front Range Region of Colorado, due to the higher altitude. The Colorado Automobile Inspection and Readjustment (AIR) Program was designed and implemented in an effort to reduce the contributions to ambient air pollution from mobile sources. The intent of this study is to evaluate whether there is a difference in the effectiveness of the Colorado AIR Program on the major technological groups of emissions control configurations.
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