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1983-02-01
Technical Paper
830767
William E. Howell, Bruce D. Fisher
An investigation of the effects of severe in-flight weather environments on composite structures has been conducted as part of the NASA-Langley Research Center Storm Hazards Program. The on-going program uses an extensively-instrumented F-106B airplane to make thurderstorm penetrations. The vertical fin cap was chosen for the experimental composite structure because of the likelihood of lightning strike attachments and the ease of component replacement. Three components were flown and investigated. The first was the U.S. Air Force production glass/epoxy fin cap which was flame-sprayed by NASA with aluminum for lightning protection. The second fin cap was fabricated with Kevlar/epoxy fabric skins and used an aluminized glass cloth for lightning protection. The third fin cap was fabricated with graphite/epoxy fabric skins with no lightning protection. All three components were exposed to high rain rates and direct lightning strikes.
1983-02-01
Technical Paper
830647
William E. Wilson, Rudolf B. Husar
Both sulfur and nitrogen pollutants may contribute to acidification of the environment. Meausrements indicate that nitric acid is an important contributor to the acidity of snow-melt but that sulfuric acid is the major contributor to rain acidity. In summer nitrate may be utilized by biological processes which effectively neutralize one hydrogen ion per nitrate utilized. In the winter these processes may not be rapid enough to utilize the nitric acid in snow-melt before it reaches lakes and streams. Therefore, NOX may be of concern during the winter, especially in regard to acidification of lakes and streams and spring fish kills. A budgeting exercise for SO2 and NOX leads to an estimate that passenger cars contribute 5% of annual wet deposition of acidity in the U.S., 8.5% of total (wet plus dry) acid deposition, and 11% of the acidity in snow-melt, as measured at several sites in the rural, northeast U.S.
1983-02-01
Technical Paper
830642
John J. Pinto, Leonard Aronowitz
Exhaust emissions of hydrocarbons, carbon monoxide and oxides of nitrogen from a large sample of model year 1959 thru 1977 gasoline powered heavy duty vehicles were measured. Chassis dynamometer driving cycle measurements were made with laboratory grade instrumentation, and idling measurements were made with inspection-station-type instruments. Emissions were measured and fuel economy calculated with the vehicles in as-received condition and also after their engines were tuned to manufacturers’ specifications. The results should be useful for planning or evaluating heavy duty emissions control programs.
1983-02-01
Technical Paper
830217
Alexander L. Gordon
The historical development of present standards period of almost forty years. The major period F-3 with the collaboration of SAE, Coordination has been obtained. The most widely used stand SAE and ASTM. A modified form of the system is Applicable test methods are published by ASTM.
1983-02-01
Technical Paper
830099
C. Norman Cochran, Ronald H. G. McClure, Joseph J. Tribendis
About 70% of the 740 million pounds of aluminum in U.S. cars scrapped in 1982 will be recovered for the secondary aluminum industry, making cars second only to used beverage containers as a source of old aluminum scrap. By the late 1990’s aluminum could supersede ferrous materials as the component with the highest total scrap value in the car. To fully realize this value, the automotive scrap industry will probably move from methods primarily designed to recover ferrous values toward practices which decrease the mixing of materials that presently limits recovery and value for aluminum. Today’s system for recycle of used aluminum beverage cans could foreshadow development of a means for recycling automotive aluminum back to primary aluminum producers. This could be accomplished by increasing dismantling and by identification and segregation of aluminum components by alloy.
1983-02-01
Technical Paper
830630
Michael W. Leiferman, Stuart W. Martens
Prior to nationwide installation of evaporative emission controls in 1971, a significant quantity of hydrocarbon vapors was lost from fuel tank vents during vehicle operation. Earlier published quantifications of that emission source mode were based on test protocols which predated and differed significantly from the now well established 1975 Federal Test Procedure for regulatory emission measurement. This paper reports the results of a series of running loss evaporative emission tests on a fleet of 1970 cars. The testing was designed to provide experimental data under conditions consistent with the regulatory test. Uncontrolled baseline values of 6.7 g (0.9 g/mi) for 1970 cars and 6.0g (0.8 g/mi) for 1960 cars are consequently proposed as benchmarks from which to measure the extent of evaporative emission control accomplished by today's automobiles
1983-02-01
Technical Paper
830652
J. C. Dent, P. A. Lakshminarayanan
The absorption and desorption of fuel by cylinder lubricating oil films has been modelled using principles of mass transfer. Henry's Law for a dilute solution of fuel in oil is used to relate gas to liquid phase fuel concentrations. Mass transfer conductances in gas and liquid phases are considered, the former via use of Reynold's Analogy to engine heat transfer data, the latter through assuming molecular diffusion through an effective penetration depth of the oil film. Oxidation of desorbed fuel is assumed complete if the mean of burned gas and lubricating oil film temperatures is greater than 1100K,. Below this value the desorbed fuel is considered to contribute to hydrocarbon emissions. Comparison with engine test data corroborate the absorption/desorption hypothesis. The model indicates the equal importance of gas and liquid phase conductances.
1983-02-01
Technical Paper
830181
J. S. Howitt, W. T. Elliott, J. P. Mogan, E. D. Dainty
A large frontal area wall flow filter has been developed for application to heavy duty vehicles such as are utilized in underground workings, Laboratory and in-mine operation has defined critical operating parameters including: 1) soot removal efficiency, 2) initial back pressure and rate of pressure rise with operating time, 3) physical durability of filter units subjected to rigorous mining machine inertial forces and vibration, and 4) regeneration of filter units by in situ combustion of accumulated material. An analysis of the economic aspects of filter use in underground environments is presented.
1983-02-01
Technical Paper
830182
Rakesh Sachdev, Victor W. Wong, Syed M. Shahed
This paper describes the study and the results obtained to determine the performance deterioration of diesel particulate traps due to ash accumulation. Based on the ash emission rate in an engine exhaust and the full-size trap volume, a flow and distance simulation technique was developed to translate the results from bench tests of small scaled down traps to engine conditions. Fuel doped with metalloorganic additives was used to accelerate the ash loading of the scaled traps. The study was conducted on both a cellular ceramic trap and a wire-mesh trap. Results indicate that for a 60 liter, ceramic trap mounted on the exhaust of a heavy duty engine, the pressure drop, Δp, will double in approximately 90,000 km. It is also seen that for the same size wire-mesh trap, the Δp will increase by 70% of the clean trap Δp in about 200,000 km. The paper also describes the work done to determine the effect of particulate trap pore size on ash accumulation in cellular ceramic traps.
1983-02-01
Technical Paper
830180
E. Pauli, G. Lepperhoff, F. Pischinger
Monolithic ceramic filters, suitable for reducing particulate emissions to within the 0,2 g/mile emissions limit, are intermittantly loaded and regenerated. A mathematical model was developed in order to describe the processes which take place in the filter during regeneration. The basis of the calculation model, such as reaction kinetics, heat and mass transfer, energy and mass balance, and flow performance are explained. Filter temperature, soot oxidation and exhaust flow behavior are described over the length of a filter channel. A calculated and measured regeneration sequence for an engine operating point near engine full load are illustrated and compared. The results show that due to the prevailing higher temperatures, an intensified soot oxidation occurs at the rear of the channel.
1983-02-01
Technical Paper
830243
Cao Jian Du, David B. Kittelson
Particle formation, growth, coagulation and combustion in the cylinder of an indirect injection passenger car type diesel engine have been studied using a system which allows the cylinder contents to be rapidly expelled through a blowdown port, diluted, and collected in a sample bag for subsequent analysis. Characteristic blowdown times were about 0.5 ms. Samples were analyzed using a condensation nuclei counter to determine particle number concentrations and an electrical aerosol analyzer to determine particle volume concentrations in the 0.01 to 1.0 μm diameter range. Measurements were made with the engine operating at 1000 rpm and an equivalence ratio of 0.32. Peak particle number concentration in the cylinder 13 times the exhaust level, and peak particle volume (or mass) concentration in the cylinder 3 times the exhaust level were observed. These results suggest that significant particle coagulation and oxidation occur during the expansion stroke.
1983-02-01
Technical Paper
830269
M. Prigent, J. P. Brunelle, G. Blanchard, R. Dozière
It may be necessary to have recourse to catalysts in Europe to reduce automotive emissions if future legislation imposes very strict limits. Since it is not desirable to forbid the use of lead-base additives in gasoline, such catalysts must be able to withstand lead poisoning. An analysis of poisoning shows that some catalysts resist this form of deactivation better than others and that the same catalyst ages more or less quickly depending on the conditions under which it is used. Improved endurance performances can be obtained by optimizing the active phase of catalysts and their supports, as well as by implementing them at high temperatures. With gasoline containing 0.15 g/l of lead and after 40 000 km of effective running, 80% CO oxidation and 65% unburned-hydrocarbon oxidation were obtained. With 0.4 g/1 of lead, plugging occurs more quickly, and the reaction of lead deposits with the support at high temperatures tends to degrade the mechanical properties of catalysts.
1983-02-01
Technical Paper
830268
Brian Harrison, Jeffrey R. Taylor, Alan F. Diwell, Andrew Salathiel
As part of a programme to develop lead tolerant emission control catalysts for Europe, a fundamental thermodynamic approach has been used to achieve an understanding of the lead species in vehicle exhaust under widely varying conditions and to consider the possible interactions which may occur between the catalyst and lead species and which may give rise to poisoning. A model has been developed which calculates the gas stream equilibrium and identifies the most stable solid phases which precipitate from the gas phase, until a final equilibrium has been reached. Results covering a wide range of conditions are presented, and compared with rig and engine test data - providing a means for determining the proportion and composition of gaseous and solid lead compounds, and the effect of oxygen content and temperature of the exhaust on the lead species formed. The data assist in the design of total vehicle emission systems with improved lead tolerance.
1983-02-01
Technical Paper
830270
R. H. Hammerle, Y. B. Graves
Engine dynamometer and laboratory flow reactor studies of automotive catalyst deactivation caused by the use of leaded fuel indicate that there are two different deactivation mechanisms: one, which dominates between 700 and 800 C, is the poisoning of the active platinum sites by lead oxide, or perhaps lead, and the other, which occurs below 550 C, is a build up of a gas diffusion barrier of lead sulfate. Both deactivation mechanisms can be temporarily reversed. Poisoning is reversed when the platinum is freed of lead oxide by lead sulfate formation below 650 C; and the barrier formed below 550 C can be made more permeable by thermal sintering of the lead sulfate at 600 to 700 C or its decomposition to lead oxide at 700 to 800 C. However, further exposure of the catalyst will again render it inactive via the mechanism predominating in that temperature region.
1983-02-01
Technical Paper
830080
Miles F. Buchman, Bernard E. Enga
Catalytic trap oxidizers developed for use in control of particulate emissions from diesel engines have been advanced to the vehicle installation stage. This paper discusses the development of complete vehicle systems. Methods and techniques of assisted regeneration are presented along with control system concepts. Installation of the trap unit as part of an integrated vehicle exhaust system is described, along with designs and results from various prototype builds.
1983-02-01
Technical Paper
830079
Suresh T. Gulati
Thermal stresses constitute a major portion of the total stress which the ceramic wall flow filter experiences in service. The primary source of these stresses is the temperature gradients, both in radial and axial directions, which attain their maximum values during regeneration. The level of particulate loading, the flow rate, the filter size and the mounting design govern the severity of temperature gradients which, together with physical properties and aspect ratio of the filter, dictate the magnitude and distribution of thermal stresses. The filter, the mounting, and the regeneration conditions should be so designed as to minimize these stresses to insure reliable and fracture free performance of the filter throughout the lifetime of the vehicle. In this paper we present a thermal stress model, based on finite element method, which computes stresses in the axisymmetric filter subjected to linear or step temperature gradients in radial and axial directions.
1983-02-01
Technical Paper
830117
H. L. Daudel, M. J. Fieber, H. O. Hardenberg
Odorants from the exhaust gas of combustion engines can be determined qualitatively and quantitatively by means of two-dimensional gas chromatographic separation, using human sense of smell, a flame ionization detector and a mass spectrometer as detectors. Maintaining certain test conditions is the deciding factor for the success of such investigations. Considerable progress was made with regard to complete, reproducible analyses of organic exhaust components after the test equipment and procedure had been modified, and after the optimal conditions for adsorption, desorption and substance transfer into the analytical equipment had been established.
1983-02-01
Technical Paper
830120
Fumitake Chisaka
Japanease legal control of HC and NOx emissions from motor vehicles have a sufficienteffect on controling photochemical smog in HC-NOx reaction system. This thing was obtained through numerical simulations in effect equivalent to dynamic smog chamber tests using a simplified box model consisting of a reaction module and some environmental factors. Concerning the dilution capacity of R=100 %/h, if the emission flux of NOx is controled so as not to exceed 0.058 ton/km3h, the maximum concentrations of O3 and NO2, can be lowered to 0.10 and 0.023 ppm. More over, simultaneous control of both the HC and NOx so as not exceed 0.58 and 0.27 ton/km3h respectively, is predicated upon meeting both the Japanese O3 and NO3 air quality standards. It turns out that this control admits ample traffic volume 6100 cars/km2, and is a considerably more cost-effective strategy.
1983-02-01
Technical Paper
830085
Otto A. Ludecke, David L. Dimick
The EPA has established stringent requirements for levels of particulates emitted from the exhaust of diesel passenger cars. This paper summarizes six years of development activities directed towards reduction of diesel passenger car particulates. A series of conceptual approaches have been experimentally evaluated, leading to development of a regenerative particulate trap. Alternate trapping material investigations, regeneration systems, and total trap systems are reviewed. The current status of this development and required technical needs are identified.
1983-02-01
Technical Paper
830086
B. Wiedemann, U. Doerges, W. Engeler, B. Poettner
Due to good trapping abilities, the ceramic trap filter was chosen for the reduction of the particulate emission of Diesel engines. Both, tests and the analysis of the regeneration kinetic show that in real-world application the lite-off limit of 500 °C may not be exceeded. The minimum exhaust gas temperature necessary for regeneration without the use of a catalyst, can be reduced to approx. 200 °C to 250 °C with the use of fuel additives. The use of additives for the filter regeneration showed excellent results in real-world conditions as well as with endurance tests. There was no significant change in emissions or specific fuel consumption about 20,000 km as compared to the operation without additives. The regeneration dependability however, is questionable because of the destruction of the filter.
1983-02-01
Technical Paper
830082
Yoji Watabe, Koichi Irako, Toshiyuki Miyajima, Toshio Yoshimoto, Yuichi Murakami
“Trapless” Trap, which makes possible the effective collecting of particulates in diesel exhaust gas and their simultaneous combustion has been developed by use of a ceramic foam in combination with catalysts containing copper salt. From a TEM photograph, it was observed that the particulate was rapidly oxidized by mobile copper ion, showing worm-eaten like spots. Screening of various base metal salts by TGA presented CUCl2-KCl-NH4VO3 and CuCl2-KCl-(NH4)6Mo7O24 as very active catalysts for diesel particulate oxidation. They had thermal stability up to 900°C when they were supported on titania. The results obtained by measuring the back pressure using 1.8L diesel engine suggest the above trap to be a self-cleaning trapless trap.
1983-02-01
Technical Paper
830084
Charles M. Urban, Larry C. Landman, Robert D. Wagner
Methods for particulate (and associated organics) emissions control were evaluated in several diesel cars. Of the methods investigated, only “particulate traps” provided large reductions in particulate emissions. Traps evaluated included metal mesh and ceramic monolithic configurations, catalyzed and uncatalyzed. One of the cars, with a ceramic trap installed, completed fifty thousand miles of distance accumulation. No significant deterioration of emissions occurred over those fifty thousand miles.
1983-02-01
Technical Paper
830083
W. R. Wade, J. E. White, J. J. Florek, H. A. Cikanek
Thermal and catalytic techniques for regenerating particulate traps were assessed. The thermal technique used a burner which heated engine exhaust to the ignition temperature of the particulates to achieve over 90% regeneration effectiveness. HC, CO and particulate emissions resulting from combustion of particulates and burner exhaust were 25 to 50% of the allowable vehicle emissions for one CVS cycle. The fuel consumed by the burner was 9% of the fuel consumed by a vehicle over one CVS cycle. Problems with burner nozzle clogging, ignition reliability, trap durability and control system requirements were identified. In the catalytic technique, Diesel fuel containing .5 gm/gal lead and .25 gm/gal copper lowered the ignition temperature of the particulates by 425°F so that periodic regeneration occurred. The trap collected nearly all of the lead and copper resulting in limited trap life, and deposits on the engine fuel nozzles tended to increase HC emissions.
1983-02-01
Technical Paper
830437
Joachim Staab, Horst Klingenberg, Dieter Schürmann
The effort in manpower and equipment and the expense in money and time involved in carrying out the various emissions tests have considerably increased over the past years. The same holds true for the fuel economy measurements. The present-day emissions testing practice calls for complex gas sampling and dilution systems (CVS) and for a big variety of different analyzing devices. The development of a unique instrument with which the interesting emission components can be measured simultaneously and directly behind the exhaust pipe would mean a decisive improvement of this situation. In an intensive study possible measurement methods were compared and a way was pointed-out to construct such an instrument.
1983-02-01
Technical Paper
830457
Paul R. Miller, Jackson Scholl, Susan Bagley, David Leddy, John H. Johnson
Physical, chemical, and biological characterization data for the particulate emissions from a Caterpillar 3208 diesel engine with and without Corning porous ceramic particulate traps are presented. Measurements made at EPA modes 3,4,5,9,lO and 11 include total hydrocarbon, oxides of nitrogen and total particulate matter emissions including the solid fraction (SOL), soluble organic fraction (SOF) and sulfate fraction (SO4), Chemical character was defined by fractionation of the SOF while biological character was defined by analysis of Ames Salmonella/ microsome bioassay data. The trap produced a wide range of total particulate reduction efficiencies (0-97%) depending on the character of the particulate. The chemical character of the SOF was significantly changed through the trap as was the biological character. The mutagenic specific activity of the SOF was generally increased through the trap but this was offset by a decrease in SOF mass emissions.
1983-02-01
Technical Paper
830553
T. J. Callahan, Thomas W. Ryan, G. B. O'Neal, R. W. Waytuloni
The increased use of diesel-powered equipment in underground mines has prompted interest in reducing their exhaust pollutants. Control of particulate emissions without substantial penalties in other emissions or fuel consumption is necessary. This paper describes test results on a prechaaber, naturally-aspirated, four-cycle diesel engine in which two different concentrations of water-in-fuel emulsions were run. The independent variables comprising the test matrix were fuel, speed, load, injection timing, injection rate, and compression ratio. The dependent variables of the experiment included particulate and gaseous emissions and engine thermal efficiency. Regression analysis was performed on the data to determine how particulate emissions were affected by fuel and engine parameters. Results of this analysis indicated that substantial reductions in particulate emissions could be obtained by utilizing water-in-fuel emulsions.
1983-02-01
Technical Paper
830544
J. D. Murrell, S. Loos, R. Heavenrich, J. Cheng, E. LeBaron
This, the eleventh in a series of Papers on EPA fuel economy trends, emphasizes the current Model Year (1983) as usual, but also gives increased emphasis to trends in vehicle technology, including catalyst and transmission subclasses. Final “CAFE”* production volumes and MPG figures have been used to update the data bases through the 1980 Model Year, and an analytic method used in the past to allocate year-to-year fleet MPG changes to specific causes, such as weight mix shifts, has been reinstituted. Conclusions are presented on the relation between fuel economy and emission standards, catalyst types, and transmission types.
1983-02-01
Technical Paper
830574
David Ganoung
Maximum fuel economy and Low exhaust emissions can exist together if a predominantly wide-open-throttle engine operating schedule is used to complement a continuously variable transmission. Moreover, the concurrently required engine re-calibration often entails less effort than the more usual fuel consumption and emission mapping procedure.
1983-02-01
Technical Paper
830585
Robert L. Chance, Ronald G. Ceselli
Eight exhaust gas condensates were evaluated for their corrosiveness towards plain carbon steel, Type 1 aluminized steel, Galvalume, and Type 409 stainless steel. Test methods included the use of anodic polarization measurements and a cyclic immersion procedure. The corrosivity of an exhaust condensate is affected by its chemistry, which in turn may he affected by variations in fuel, engine operating conditions, type of engine, and the emission control system. Condensate pH of those tested ranged from 2.3 to 9.0. Results of the corrosion tests showed that acidic condensates were generally the most corrosive, but that substantial pitting corrosion could occur with alkaline condensates.
1983-02-01
Technical Paper
830584
Joseph E. Hunter
Condensate composition was determined for 1981–82 General Motors vehicles with a) diesel engines and no converters, b) gasoline engines with oxidizing converters, c) gasoline engines with computer command control and dual bed bead or dual bed monolith converters, and d) gasoline engines with computer command control and single bed bead converters having three-way catalysts. The pH was found to range between 2.3 and 9.2 for the systems studied. Anions present in low pH condensates were sulfate, nitrate and chloride. Near neutral condensates and basic condensates also contained ammonia plus bicarbonate and carbonate anion, and had generally higher sulfate content than the acid condensates. Results are shown to be related primarily to differences resulting from the catalytic reduction of NOX and fuel sulfur content.
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