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Three heats of 0.40% carbon microalloyed steel, containing either 0.03 % or 0.10% sulfur, and with and without a 0.09% vanadium addition, were subjected to metallographic analysis and mechanical property testing. Bars were heated to austenitizing temperatures, between 1000°C and 1300°C. Significant amounts of intragranular ferrite, which has been associated with improved toughness, formed only in specimens containing vanadium and high sulfur which were austenitized above 1100°C. The balance of the microstructure consisted of ferrite which formed at prior austenite grain boundaries and large amounts of pearlite. High densities of manganese sulfide particles in the steels with high sulfur content effectively retarded austenite grain growth. The formation of significant amounts of intragranular ferrite decreased mean free ferrite spacing, effectively refined the pearlite structure, and lowered the Charpy V-notch impact transition temperature.

A running loss test procedure has been developed which integrates a point-source collection method to measure fuel evaporative running loss from vehicles during their operation on the chassis dynamometer. The point-source method is part of a complete running loss test procedure which employs the combination of site-specific collection devices on the vehicle, and a sampling pump with sampling lines. Fugitive fuel vapor is drawn into these collectors which have been matched to characteristics of the vehicle and the test cell. The composite vapor sample is routed to a collection bag through an adaptation of the ordinary constant volume dilution system typically used for vehicle exhaust gas sampling. Analysis of the contents of such bags provides an accurate measure of the mass and species of running loss collected during each of three LA-4* driving cycles. Other running loss sampling methods were considered by the Auto-Oil Air Quality Improvement Research Program (AQIRP or Program).

An OEM Natural Gas Vehicle (NGV) has been developed to address recently enacted Clean-Fuel Vehicle legislation. The NGV incorporates advanced fuel storage and fuel metering technologies to produce very low emissions and to provide superior customer value compared to aftermarket conversion units.

Natural gas-fueled vehicles impose unique requirements on exhaust aftertreatment systems. Methane conversion, which is very difficult for conventional automotive catalysts, may be required, depending on future regulatory directions. Three-way converter operating windows for simultaneous conversion of HC, CO, and NOx are considerably more narrow with gas engine exhaust. While several studies have demonstrated acceptable fresh converter performance, aged performance remains a concern. This paper presents the results of a durability study of eight catalytic converters specifically developed for natural gas engines. The converters were aged for 300 hours on a natural gas-fueled 7.0L Chevrolet engine operated at net stoichiometry. Catalyst performance was evaluated using both air/fuel traverse engine tests and FTP vehicle tests. Durability cycle severity and a comparison of results for engine and vehicle tests are discussed.

Typical sand-casting techniques have been shown to be inappropriate in pouring particulate reinforced aluminum metal matrix composite (Al-MMC) castings. New gating/risering configurations were necessary to produce castings of acceptable soundness. Several automotive components, including brake rotors, cylinder liners and camshaft thrust plates, were prepared using special techniques. Initial durability test results of several Al-MMC prototype components are presented.

Most of the current fuel supply specifications, including the key parameters in the transient fuel control strategies, are experimentally determined since the complexity of multiphase fuel flow behavior inside the intake manifold is still not quantitatively understood. Optimizing these specifications, especially the parameters in transient fueling systems, is a key issue in improving fuel efficiency and reducing exhaust emissions. In this paper, a model of fuel spray, wall-film flow and wall-film vaporization has been developed to gain a better understanding of the multiphase fuel-flow behavior within the intake manifold which may help to determine the fuel supply specifications in a multi-point injection system.

Vacuum insulation and phase-change thermal storage have been used to enhance the heat retention of a prototype catalytic converter. Storing heat in the converter between trips allows exhaust gases to be converted more quickly, significantly reducing cold-start emissions. Using a small metal hydride, the thermal conductance of the vacuum insulation can be varied continuously between 0.49 and 27 W/m2K (R-12 to R-0.2 insulation) to prevent overheating of the catalyst. A prototype was installed in a Dodge Neon with a 2.0-liter engine. Following a standard preconditioning and a 23-hour cold soak, an FTP (Federal Test Procedure) emissions test was performed. Although exhaust temperatures during the preconditioning were not hot enough to melt the phase-change material, the vacuum insulation performed well, resulting in a converter temperature of 146°C after the 23-hour cold soak at 27°C.

Engine misfires cause a negative impact on exhaust emissions. Severe cases could damage the catalyst system permanently. These are the basic reasons why CARB (California Air Resources Board) mandated the detection of engine misfires in their OBD II (On-Board Diagnostics II) regulations. For the last several years, automobile manufacturers and their suppliers have been working diligently on various solutions for the “Misfire Detection” challenge. Many have implemented a solution called “Crankshaft Velocity Fluctuation” (CVF), which utilizes the crank sensor input to calculate the variation of the crankshaft rotational speed. The theory is that any misfires will contribute to a deceleration of the crankshaft velocity due to the absence of pressure torque. This approach is marginal at best due to the fact that there could be many contributors to a crankshaft velocity deceleration under various operating conditions. To sort out which is a true misfire is a very difficult task.

A cycle-by-cycle analysis of HC emissions from each cylinder of a four-stroke V-6, 3.3 L production engine was made during cold start. The HC emissions were measured in the exhaust port using a high frequency flame ionization detector (FID). The effect of the initial startup position of the piston and valves in the cycle on combustion and HC emissions from each cylinder was examined. The mass of fuel injected, burned and emitted was calculated for each cycle. The equivalence ratio of the charge in the firing cycles was determined. The analysis covered the first 120 cycles and included the effect of engine transients on HC emissions.

Environmental issues have significantly impacted automotive operations worldwide. Countries are continuing to ratchet down their allowable emissions and to remain competitive, all industries must take Life Cycle Management (LCM) and implement it into everyday practice. Economic competitiveness as a part of economic development is central to the nation's social and financial well-being. America must catch-up to the rest of the world in how it views government and industry relationships as well as how to focus costs within the corporate structure. The adversarial relationships between government and industry must give way to stronger partnerships. For this concept to succeed a long term view of problems must be made by a corporation and both short and long term actions taken to resolve these problems. Industry must help create the market for recycled goods and must “walk the talk” by using recycled goods where possible.

The effect of diesel cetane number, total aromatic content T90, and fuel nitrogen content on regulated emissions (HC, CO, NOx, and PM) from a 1991 DDC Series 60 engine were measured Emissions tests were conducted using the EPA heavy-duty transient test (CFR 40 Part 86 Subpart N) at a laboratory located 5,280 feet (1609 m) above sea level. The objective of this work was to determine if the effect of fuel chemistry at high altitude is similar to what is observed at sea level and to examine the effect of specific fuel chemistry variables on emissions. An initial tea series was conducted to examine the effect of cetane number and aromatics. Transient emissions for this test series indicated much higher (50 to 75%) particulate emissions at high altitude than observed on the same model engine and similar fuels at sea level.

Methane emissions from lean-burn natural gas engines can be relatively high. As natural gas fueled vehicles become more prevalent, future regulations may restrict these emissions. Preliminary reports indicated that conventional, precious metal oxidation catalysts rapidly deactivate (in less than 50 hours) in lean-burn natural gas engine exhaust. This investigation is directed at quantifying this catalyst deactivation and understanding its cause. The results may also be relevant to oxidation of lean-burn propane and gasoline engine exhaust. A platinum/palladium on alumina catalyst and a palladium on alumina catalyst were aged in the exhaust of a lean-burn natural gas engine (Cummins B5.9G). The engine was fueled with compressed natural gas. Catalyst aging was accomplished through a series of steady state cycles and heavy-duty transient tests (CFR 40 Part 86 Subpart N) lasting 10 hours. Hydrocarbons in the exhaust were speciated by gas chromatography.

Regulated emissions (THC, CO, NOx, and PM) and particulate SOF and sulfate fractions were determined for a 1995 Detroit Diesel Series 50 urban bus engine at varying fuel sulfur levels, with and without catalytic converters. When tested on EPA certification fuel without an oxidation catalyst this engine does not appear to meet the 1994 emissions standards for heavy duty trucks, when operating at high altitude. An ultra-low (5 ppm) sulfur diesel base stock with 23% aromatics and 42.4 cetane number was used to examine the effect of fuel sulfur. Sulfur was adjusted above the 5 ppm level to 50, 100, 200, 315 and 500 ppm using tert-butyl disulfide. Current EPA regulations limit the sulfur content to 500 ppm for on highway fuel. A low Pt diesel oxidation catalyst (DOC) was tested with all fuels and a high Pt diesel oxidation catalyst was tested with the 5 and 50 ppm sulfur fuels.

Temperature variation and heat transfer phenomena in the intake port of a spark ignition engine with port injection play a significant role in the mixture preparation process, especially during the warm up period. Cold temperatures in the intake port result in a large amount of liquid-fuel film. Since the liquid-fuel film responds at a slower speed than the gas-phase flow during transient operations, the liquid-fuel film acts as a fuel sink (or source) and can degrade the vehicle's driveability, fuel economy, and emissions control. In this work, a one-dimensional, unsteady, multicomponent, multiphase flow model has been developed to study the mixture formation process in the intake port for a modern, multipoint-fuel-injection, gasoline engine. The droplet, liquid film and gas-phase mixture temperature variations and the effects of charge air, initial fuel and port wall temperatures involved in generating the air-fuel mixture are examined.

A few years ago, electric vehicles (EVs) were considered to be objects of the distant future … technology that was still in its infancy, not yet ready and for those outside the “high pollution” areas probably not even worth the expenditure. But the present day scenario has changed dramatically. In the United States of America, several states are following California's lead and the need for the operating fleets to commit to purchase of Zero Emission vehicles (ZEVs) is becoming a requirement. In order to make the technology available to the utilities … as well as the public, state of the art, affordable batteries are essential for making EVs a reality and an effective means of transportation.

Due to new regulations, emissions development and compliance testing have become more complex. The amount of data acquired, the number of test types, and the variety of test conditions have increased greatly. Due to this increase, managing test information from request to analysis of results has become a critical factor. Also, automated test result presentation and test storage increases the value and quality of each test. This paper describes a computer system developed to cope with the increasing complexity of vehicle emission testing.

The goal of this project is the development and characterization of synthetic membranes for the separation and purification of CO2 from the Martian atmosphere for in-situ resource utilization (ISRU) applications such as in-situ propellant production. Candidate materials should have high selectivity for carbon dioxide over nitrogen and argon, and a glass transition temperature of -40 °C or less to remain in rubbery state at low temperature for high permeance (flux/driving force). Membrane materials we identified include the rubbery polymers poly(dimethyl siloxane) (PDMS) and the copolymer poly(dimethyl, methylphenyl siloxane) (PMPS). Pure and mixed gas permeation experiments with CO2, N2 and Ar were performed with these membrane materials in the temperature range -25 to 21 °C. In experiments with the commercially available PDMS membranes, the pure gas CO2 permeability increases from 1932 Barrers to 2755 Barrers as the temperature decreases from 22 to -30 °C.

Most environments inhabited by living beings have dust. Much of that dust comes from the continuous flaking of our own skin and atmosphere borne particles of submicron size. Dust mites seem to play an important role in integrating fine scale dust, which they consume to grow, resulting in larger length scale dust. Dust continues to agglomerate and grow. Air filters are designed to remove dust and control dust agglomeration. We report a simple scaling law, based on kinematic simulations of dust filtration through a one dimensional idealized filter. The results reveal insights regarding how filters may clog in time. Our results may be of use to someone interested in designing customized air filters for optimum dust removal in an environment with a known dust distribution.

Since 1968, vehicle weight increases and emissions controls have reduced fuel economy substantially. Additional losses in economy and acceleration will be experienced through 1976. Recommendations are made to lessen the impact of the predicted losses. Factors influencing fuel economy and acceleration are examined for an intermediate car. Changes in engine efficiency and displacement, compression ratio, torque converter, transmission, axle ratio, aerodynamic drag, tires, accessories, vehicle weight, and emissions controls are examined. When practical, the effects of 10% changes are analyzed. Comparisons are also made with a subcompact and a luxury vehicle.

The use of a soy-based diesel fuel (biodiesel) has potential advantages over the use of a conventional petroleum diesel fuel including: Reduced dependence on foreign petroleum Lowering of greenhouse gas emissions Less air pollution and related public health risks in urban areas A life cycle study performed by the U.S. Department of Energy's National Renewable Energy Laboratory, the U.S. Department of Agriculture's Office of Energy and Ecobalance (completed in May 1998) helped to quantify the environmental benefits of the “cradle-to-grave” production and use of biodiesel. The study showed, for example, that substituting 100% biodiesel for petroleum diesel in urban buses reduced the life cycle emissions of carbon dioxide (CO2) by 78%. The study also pointed out some trade-offs of using biodiesel including increased life cycle hydrocarbon and NOx emissions.