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The equipment for collecting dilute exhaust samples involves the use of bag materials (i.e., Tedlar®) that emit hydrocarbons that contaminate samples. This study identifies a list of materials and treatments to produce bags that reduce contamination. Based on the average emission rates, baked Tedlar®, Capran® treated with alumina deposition, supercritical CO2 extracted Kynar® and supercritical CO2 extracted Teflon NXT are capable of achieving the target hydrocarbon emission rate of less than 15 ppbC per 30 minutes. CO2 permeation tests were also performed. Tedlar, Capran, Kynar and Teflon NXT showed comparable average permeation rates. Based on the criteria of HC emission performance, changes in measured CO2 concentration, ease of sealing, and ease of surface treatment, none of the four materials could be distinguished from one another.

Typically, an engine/dynamometer thermal aging cycle contains combinations of elevated catalyst inlet temperatures, chemical reaction-induced thermal excursions (simulating misfire events), and average air/fuel ratio's (AFR's) to create a condition that accelerates the aging of the test part. In theory, thermal aging is predominantly a function of the time at an exposure temperature. Therefore, if a burner system can be used to simulate the exhaust AFR and catalyst inlet and bed temperature profile generated by an engine running an accelerated aging cycle, then a catalyst should thermally age the same when exposed to either exhaust stream. This paper describes the results of a study that examined the aging difference between six like catalysts aged using the Rapid Aging Test (RAT) cycle (an accelerated thermal aging cycle). Three catalysts were aged using a gasoline-fueled engine aging stand; the other three were aged using a computer controlled burner system.

The U.S. Army's National Automotive Center has contracted with Illinois Institute of Technology Research Institute (IITRI), Southwest Research Institute (SwRI), and Advanced Propulsion, LLC, to evaluate the effects on fuel consumption and logistics that would result from hybridizing the powertrains of the Army's tactical wheeled vehicle fleet. This paper will outline the approach taken to perform that evaluation and present a synopsis of results achieved to date.

The Environmental Protection Agency (EPA) is developing emission standards for nonroad spark-ignition engines rated over 19 kW. Existing emission standards adopted by the California Air Resources Board for these engines were derived from emission testing with new engines, with an approximate adjustment applied to take deterioration into account. This paper describes subsequent testing with two LPG-fueled engines that had accumulated several thousand hours of operation with closed-loop control and three-way catalysts. These engines were removed from forklift trucks for characterization and optimization of emission levels. Emissions were measured over a wide range of steady-state points and several transient duty cycles. Optimized emission levels from the aged systems were generally below 1.5 g/hp-hr THC+NOx and 10 g/hp-hr CO.

This study compared four different candidate fuels which were prepared by blending different components with a typical No. 2 diesel. Two fuels were blended with a synthetic diesel prepared from natural gas condensate, and all candidate fuels were splash blended with a proprietary additive package from International Fuel Technology Inc. (IFT). These fuels were then compared to the No. 2 diesel and to a California Air Resources Board (CARB) equivalent diesel fuel. The comparisons included fuel properties such as sulfur content, aromatics, cetane, lubricity, distillation; emissions; and fuel consumption. Emission testing was conducted on a 1991 Detroit Diesel Series 60. The Environmental Protection Agency (EPA) transient cycle was utilized for emissions, fuel characterization was performed according to ASTM standards, and fuel consumption was calculated by the carbon balance method.

The Environmental Protection Agency (EPA) has proposed emission standards for nonroad spark-ignition engines rated over 19 kW. Existing emission standards adopted by the California Air Resources Board require testing on a steady-state duty cycle. This paper presents the results of measurements to characterize normal operation from forklift trucks, which are the dominant application for these engines. In combination with previous measurements with a welder to represent constant-speed applications, the measured data were used to derive a composite 20-minute transient duty cycle for emission testing for all nonroad industrial spark-ignition engines.

It has been shown within the catalyst industry that the emission performance with higher cell density technology and therefore with higher specific geometric area is improved. The focus of this study was to compare the overall performance of high cell density catalysts, up to 1600cpsi, using a MY 2001 production vehicle with a 4.7ltr.V8 engine. The substrates were configured to be on the edge of the design capability. The goal was to develop cost optimized systems with similar emission and back pressure performance, which meet physical and production requirements. This paper will present the results of a preliminary computer simulation study and the final emission testing of a production vehicle. For the pre-evaluation a numerical simulation model was used to compare the light-off performance of different substrate designs in the cold start portion of the FTP test cycle.

Atmospheric corrosion of steels, aluminum alloys, and Al-clad aluminum alloys is a problem for many civil engineering structures, commercial and military vehicles, and aircraft. Paint is usually the primary means to prevent the corrosion of steel bridge components, automobiles, trucks, and aircraft. Under ideal conditions, the coating provides a continuous layer that is impervious to moisture. At present, maintenance cycles for commercial and military aircraft and ground vehicles, as well as engineered structures, is based on experience and appearance rather than a quantitative determination of coating integrity. To improve the maintenance process and reduce costs, sensors are often used to monitor corrosion. The present suite of sensors designed to detect corrosion and marketed to predict the lifetime of the engineered components, however, are not useful for determining the condition of the protective paint coatings.

This study compared diesel exhaust emission from four different diesel fuels: a conventional low sulfur D2 diesel (0.03% sulfur, 28% aromatics), California Air Resources Board (CARB) diesel (0.015% sulfur, 8% aromatics), “Swedish” diesel (<0.001% sulfur, 4% aromatics), and a Fischer-Tropsch (F-T) diesel (<0.0001% sulfur, <0.1% aromatics) fuel. The comparison included regulated emissions, hydrocarbon speciation, air toxics, aldehydes and ketones, particle size distribution, and greenhouse gas emissions. Testing was conducted using a Cummins B-Series engine installed both in a heavy light-duty truck operating on a chassis dynamometer and on an engine dynamometer. The chassis driving cycles included city, highway, and aggressive driving operation. Engine dynamometer tests included the U.S. transient cycle.

Engine tests are widely used to measure the ability of lubricating oils to reduce fuel consumption through improved mechanical efficiency. Previous publications have correlated laboratory-scale tests with the well-established Sequence VI and VIA engine methods. The present paper uses a matrix of 66 oils to produce an empirical model for the recently developed Sequence VIB engine test. A smaller matrix of oils was available for correlation with Sequence VI and VIA results. The models combine a purposely-designed friction test with conventional measures of kinematic and high-temperature high-shear viscosity. Good correlation was obtained with the Sequence VI, VIA and VIB results, as well as each of the five stages in the Sequence VIB test. The effects of lubricant oxidation in the 96-hour FEI-2 portion of the Sequence VIB test were similar for each of the oils. As a result, good correlation was observed between FEI-1 and FEI-2 results from the VIB test.

Criteria pollutants were measured from ten Class 7 and 8 (i.e., gross vehicle weights > 33,000 lb) heavy-duty diesel trucks with engine model years between 1953 and 1975. The data was used by EPA to estimate that period's particulate matter emission rates for these type engines and will be used to develop dose response relationships with existing epidemiological data. Particulate samples were analyzed for sulfate and volatile organic fraction. Carbon soot was estimated. The trucks had particulate emissions of 2 to 10 g/mi as compared to 1 to 6 g/mi for trucks with model year engines from 1975 through the mid-1980s, and less than 1 g/mi for post-1988 trucks.

To reach its objective of reducing vehicle fuel consumption by 50 percent, the development of the 21st Century Truck (21T) will address all the aspects of truck design contributing to the achievement of that goal. [1] This paper will address one of these aspects, specifically vehicle parasitic loss reduction with special emphasis on drive train losses, concentrating on the potential benefits of replacing mechanical coolant (water) and oil pumps with electrically powered pumps.

This paper describes an on-vehicle demonstration of a hydrogen-heated catalyst (HHC) system for reducing the level of cold-start hydrocarbon emissions from a gasoline-fueled light-duty vehicle. The HHC system incorporated an onboard electrolyzer that generates and stores hydrogen (H2) during routine vehicle operation. Stored hydrogen and supplemental air are injected upstream of a platinum-containing automotive catalyst when the engine is started. Rapid heating of the catalytic converter occurs immediately as a result of catalytic oxidation of hydrogen (H2) with oxygen (O2) on the catalyst surface. Federal Test Procedure (FTP) emission results of the hydrogen-heated catalyst-equipped vehicle demonstrated reductions of hydrocarbons (HC) and carbon monoxide (CO) up to 68 and 62 percent, respectively. This study includes a brief analysis of the emissions and fuel economy effects of a 10-minute period of hydrogen generation during the FTP.

Comparative exhaust emission tests were performed with five diesel fuels, namely a Sasol Fischer-Tropsch diesel, a fuel meeting the CARB diesel fuel specification, a fuel meeting the US 2-D diesel fuel specification, and two blends of the Fischer-Tropsch diesel and the 2-D diesel. Hot-start and cold-start heavy-duty transient emission tests were performed using a 1999 model year DDC series 60 engine. Regulated exhaust emissions with the Fischer-Tropsch diesel were significantly lower than with the 2-D and CARB diesel fuels, in both the hot-start and cold-start tests. When compared with test results obtained previously with a 1991 engine, it was found that the reduction in NOX with the Fischer-Tropsch fuel was smaller in the 1999 engine, while the reduction in PM was greater.

Particle number concentrations and size distributions were measured for the diluted exhaust of a 1991 diesel engine during the US FTP transient cycle for heavy-duty diesel engines. The engine was operated on US 2-D on-highway diesel fuel. The particle measurement system consisted of a full flow dilution tunnel as the primary dilution stage, an air ejector pump as the secondary dilution stage, and an electrical low pressure impactor (ELPI) for particle size distribution measurements. Particle number emission rate was the highest during the Los Angeles Non Freeway (LANF) and the Los Angeles Freeway (LAF) segments of the transient cycle. However, on brake specific number basis the LAF had the lowest emission level. The particle size distribution was monomodal in shape with a mode between 0.084 μm and 0.14 μm. The shape of the size distribution suggested no presence of nanoparticles below the lower detection limit of the instrument (0.032 μm), except during engine idle.

The use of biodiesel fuels derived from vegetable oils or animal fats as a substitute for conventional petroleum fuel in diesel engines has received increased attention. This interest is based on a number of properties of biodiesel including the fact that it is produced from a renewable resource, its biodegradability, and its potential beneficial effects on exhaust emissions. As part of Tier 1 compliance requirements for EPA's Fuel Registration Program, a detailed chemical characterization of the transient exhaust emissions from three modern diesel engines was performed, both with and without an oxidation catalyst. This characterization included several forms of hydrocarbon speciation, as well as measurement of aldehydes, ketones, and alcohols. In addition, both particle-phase and semivolatile-phase PAH and nitro-PAH compounds were measured. Unregulated emissions were characterized with neat biodiesel and with a blend of biodiesel and conventional diesel fuel.

Nanoparticle formation during exhaust sampling and dilution has been examined using a two-stage micro-dilution system to sample the exhaust from a modern, medium-duty diesel engine. Growth rates of nanoparticles at different exhaust dilution ratios and temperatures have been determined by monitoring the evolution of particle size distributions in the first stage of the dilution system. Two methods, graphical and analytical, are described to determine particle growth rate. Extrapolation of size distribution down to 1 nm in diameter has been demonstrated using the graphical method. The average growth rate of nanoparticles is calculated using the analytical method. The growth rate ranges from 6 nm/sec to 24 nm/sec, except at a dilution ratio of 40 and primary dilution temperature of 48 °C where the growth rate drops to 2 nm /sec. This condition seems to represent a threshold for growth. Observed nucleation and growth patterns are consistent with predictions of a simple physical model.

Recent advances in Variable Valve Actuation (VVA) methods have led to development of optimized valve timing strategies for a broad range of engine operating conditions. This study focuses on the cold-start period, which begins at engine cranking and lasts for approximately 1 minute thereafter. Cold-start is characterized by poor mixture preparation due to low component temperatures, aggravated by fixed valve timing which has historically been compromised to give optimal warm engine operation. In this study, intake cam phasing was varied to explore the potential benefit in hydrocarbon emissions and driveability obtainable for cold-start. A simple experimental approach was used to investigate the potential emissions benefits realizable through intake cam phasing. High speed cylinder pressure and Fast Flame Ionization Detector (FFID) engine-out hydrocarbon (HC) measurements were made to characterize instantaneous cold-start emissions and driveability.

The purpose of this project was to modify existing small off-road engines to meet ARB's originally proposed 1999 emissions standards. A particular point was to show that compliance could be attained without the need to redesign the base engines. Four high-sales volume, ARB-certified 1997 model engines were selected from the following categories: 1) handheld two-stroke engine, 2) handheld four-stroke engine, 3) non-handheld side-valve engine, and 4) a non-handheld overhead-valve engine. Engines were selected, procured, and baseline emission tested using applicable ARB test procedures. Appropriate emission control strategies were then selected and applied to the four engines. Emission reduction strategies used included air/fuel ratio optimization, and catalytic aftertreatment. Following the development of the four emission-controlled engines, final, certification-quality emissions tests were performed. All four engines met ARB's original 1999 Tier 2 emission standards after development.

The Beta ratio and filtration ratio are two common rating systems used to designate the abrasive filtration efficiency of fuel filters. Previous research developed a series of wear curves to predict the effects of abrasive particles of varying sizes on fuel injector performance. Based on this data, a formula was generated to predict injector wear based on the number of 5-, 10-, and 15-μm particles in the effluent. This value is called the wear index. (1,2)1 Various fuel filters with the same manufacturer rating were evaluated on a test engine to determine the wear index for each of these fuel filters. The results demonstrate the differences between these “similar” fuel filters and how the wear index provides additional information as compared to Beta and filtration ratios.