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COMPARISON of work capacity per unit mass and volume of different energy carriers shows that liquid hydrocarbons are superior to other energy sources. Solar and nuclear powerplants as well as their use in conjunction with a steam engine are examined in this paper. Suitability of an electric drive is discussed. Using a production 2-stroke diesel engine and its development forecast, a comparison is made of spark ignition, diesel, and gas turbine engines. The status of the free-piston engine turbine combination is reviewed.

Nearly a third of the fuel energy is wasted through the exhaust of a vehicle. An efficient waste heat recovery process will undoubtedly lead to improved fuel efficiency and reduced greenhouse gas (GHG) emissions. Currently, there are multiple waste heat recovery technologies that are being investigated in the auto industry. One innovative waste heat recovery approach uses Thermoacoustic Converter (TAC) technology. Thermoacoustics is the field of physics related to the interaction of acoustic waves (sonic power) with heat flows. As in a heat engine, the TAC produces electric power where a temperature differential exists, which can be generated with engine exhaust (hot side) and coolant (cold side). Essentially, the TAC converts exhaust waste heat into electricity in two steps: 1) the exhaust waste heat is converted to acoustic energy (mechanical) and 2) the acoustic energy is converted to electrical energy.

Meeting the California Medium-Duty truck emissions standards presents a significant challenge to automotive engineers due to the combination of sustained high temperature exhaust conditions, high flow rates and relatively high engine out emissions. A successful catalyst for an exhaust treatment system must be resistant to high temperature deactivation, maintain cold start performance and display high three-way conversion efficiencies under most operating conditions. This paper describes a catalyst technology and precious metal loading study targeting a California Medium-Duty truck LEV (MDV2) application. At the same time a direction is presented for optimizing toward the Federal Tier 1 standard through reduction of precious metal use. The paper identifies catalytic formulations for a twin substrate, 1.23 L medium-coupled converter. Two are used per vehicle, mounted 45 cm downstream of each manifold on a 5.7 L V8 engine.

Diesel exhaust after treatment solutions using injection, such as urea-based SCR and lean NOx trap systems, effectively reduce the emission NOx level in various light vehicles, commercial vehicles, and industrial applications. The performance of the injector is crucial for successfully utilizing this type of technology, and a simulation tool plays an important role in the virtual design, that the performance of the injector is evaluated to reach the optimized design. The virtual test methodology using CFD to capture the fluid dynamics of the injector internal flow has been previously developed and validated for quantifying the dosing rate of the test injector. In this study, the capability of the virtual test methodology was extended to determine the spray angle of the test injector, and the effect of the manufacturing process on the injector internal nozzle flow characteristics was investigated using the enhanced virtual test methodology.

The diesel particulate filter (DPF) is a critical aftertreatment device for control of particulate matter (PM) emissions from a diesel engine. DPF survivability is challenged by several key factors such as: excessive thermal stress due to DPF runaway regenerations (or uncontrolled regeneration) may cause DPF substrate and washcoat failure. Catalyst poisoning elements from the diesel fuel and engine oil may cause performance degradation of the catalyzed DPF. Harsh vibration from the powertrain, as well as from the road surface, may lead to mechanical failure of the substrate and/or the matting material. Evaluations of these important validation parameters were performed.

Splash and spray conditions created by tractor-trailer combinations operating on the Federal highway system have been studied and tested for many years with mixed results. Past events are reviewed briefly in this paper. In additional testing during 1983, using new state-of- the-art splash/spray suppressant devices, some encouragement was provided that these devices could work. The 1984 Motor Vehicle Manufacturers Association (MVMA) test program was designed to develop practicable and reliable test procedures to measure effectiveness of splash and spray reduction methods applied to tractor-trailer combination vehicles. Over 40 different combinations of splash/spray suppression devices on five different tractors and three van trailer types were tested. The spray-cloud densities for some 400 test runs were measured by laser transmissometers and also recorded by still photography, motion pictures, and videotape. On-site observers made subjective ratings of spray density.

This study evaluated multi-layer steel and composite head gaskets of various thicknesses (0.43 to 1.5 mm) and fire-ring diameters to determine the influence of head gasket crevices on engine-out hydrocarbon (HC) emissions. The upper limit in the percent reduction in HC emissions from gasket-design modifications is estimated to be about 15%. At part-load conditions, the lowest HC emissions were measured for head-gasket thickness of about 1 mm. Significantly smaller thicknesses of the order of 0.4 mm result in an increase in HC emissions. Substantial hydrocarbon-emissions advantage may be realized by minimizing the gasket-to-cylinder bore offset.

Meeting regulated tailpipe emission standards requires a full system approach by automotive engineers encompassing: engine design, combustion system metrics, exhaust heat management, aftertreatment design and exhaust system packaging. Engine and combustion system design targets define desired engine out exhaust constituents, exhaust gas temperatures and oil consumption rates. Protecting required catalytic converter volume in the engine bay for stricter tailpipe emission standards is becoming more difficult. Future fuel economy mandates are leading to vehicle downsizing which is affecting all aspects of vehicle component packaging. In this study, we set out to determine the potential palladium (Pd) cost penalty as a result of increased light-off time required as a catalyst is positioned further away from the engine. Two aged converter systems with different Pd loadings were considered, and EPA FTP-75 emission tested at six different catalyst positions.

Diesel exhaust gas dilution and odor intensity were measured in the immediate vicinity of a transit bus equipped with a rear-mounted horizontal exhaust pipe, a rear-mounted vertical exhaust pipe, and a roof-top diffusion system. Exhaust dilution ratios were measured indoors during vehicle idle operation, using propane added to the exhaust gas as a tracer. Exhaust odor intensities were measured also indoors during vehicle idle operation by a human panel, using a threshold odor measurement technique. On the average, the dilution of the exhaust gas around the bus with the vertical exhaust pipe was about eight times greater than it was with the horizontal pipe. Odor intensity, as measured by the threshold response distance, was about 35% less with the vertical pipe than with the horizontal pipe. The roof-top diffuser was not as effective as the vertical exhaust pipe in increasing exhaust gas dilution or in reducing exhaust odor intensity.

Several factors have influenced the size and design of domestic passenger cars over the past 30 years. Of most significance has been the influx of imported cars, initially from Europe, later from Japan. Interspersed within the fabric of this influx have been two energy crises and several recessions, and the onset of safety, emission, and energy regulations. These factors have led to various responses by domestic manufacturers as indicated by the types of products and vehicle systems that they have introduced during this period. This paper chronicles both the events as well as the responses.

In order to meet progressively stringent regulations on particulate emission from diesel engines, GM has developed and tested a variety of trap oxidizer systems over the years. A particulate trap system for a light duty diesel engine has been selected and developed based on this experience, with particular emphasis on production feasibility. The system components have been designed and developed in collaboration with potential suppliers, to the extent possible. The technical performance of this system has been demonstrated by successful system durability testing in the test cell and vehicle experience in computer controlled automatic operation mode. Although the system shows promise, its production readiness will require more development and extensive vehicle validation under all operating conditions.

Stringent global emissions legislation demands effective NOx reduction strategies, particularly for the aftertreatment, and current typical liquid urea SCR systems achieve efficiencies greater than 90% [1]. However, with such high-performing systems comes the trade-off of requiring a tank of reductant (urea water solution) to be filled regularly, usually as soon as the fuel fillings or as far as oil changes. Advantages of solid reductants, particularly ammonium carbamate, include greater ammonia densities, enabling the reductant refill interval to be extended several multiples versus a given reductant volume of urea, or diesel exhaust fluid (DEF) [2]. An additional advantage is direct gaseous ammonia dosing, enabling reductant injection at lower exhaust temperatures to widen its operational coverage achieving greater emissions reduction potential [3], as well as eliminating deposits, reducing mixing lengths, and avoiding freeze/thaw risks and investments.

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).

This report presents the test methods and results of a study involving lap/shoulder belted dummies in dynamic dolly rollover tests and inverted vehicle drop tests. Data are presented showing dummy neck loadings resulting from head impacts to the vehicle interior as the vehicle contacts the ground. Comparison of the number and magnitude of axial neckloads are presented for rollcaged and production vehicles, as well as an analysis of the factors which influence neckloads under these conditions.

This paper presents an extensive research program undertaken to develop improved side impact test methods. The development of a component side impact test device along with an associated test procedure are reviewed. The results of accident data analysis techniques to define anatomical areas most likely to be injured during side impact and definition of test device response corridors based on human surrogate testing conducted by the Association Peugeot/Renault and the University of Heidelberg are discussed. The relationship of response corridors and accident data analysis in earlier phases of the project resulted in definition and development of a component side impact test device to represent the human thorax. A test program to evaluate and compare component and full-vehicle test results is presented.

This paper summarizes the results of tests conducted with anesthetized animals that were exposed to a wide range of passenger inflatable restraint cushion forces for a variety of impact sled - simulated accident conditions. The test configurations and inflatable restraint system concepts were selected to produce a broad spectrum of injury types and severities to the major organs of the head, neck and torso of the animals. These data were needed to interpret the significance of the responses of an instrumented child dummy that was being used to evaluate child injury potential of the passenger inflatable restraint system being developed by General Motors Corporation. Injuries ranging from no injury to fatal were observed for the head, neck and abdomen regions. Thoracic injuries ranged from no injury to critical, survival uncertain.

The function of the inlet header of a catalytic converter is to diffuse the inlet exhaust flow, decreasing its velocity and increasing its static pressure with as little loss in total pressure as possible. In practice, very little diffusion takes place in most catalytic converter inlet headers because the flow separates at the interface of the pipe and the tapered section leading to the substrate. This leads to increased converter pressure loss and flow maldistribution. An improved inlet-header design called the Enhanced Diffusion Header (EDH) was developed which combines a short, shallow-angle diffuser with a more abrupt expansion to the substrate cross section. Tests conducted in room air (cold flow) and engine exhaust showed that improved inlet-jet diffusion leads to substantial reductions in converter restriction. EDH performance was not compromised by the presence of a right-angle bend upstream of the converter.

The ozone forming potential (OFP) and specific reactivity (SR) of tailpipe exhaust are among the regulated factors that determine the environmental impact of a motor vehicle. OFP and SR measurements require a lengthy determination of about 160 non-methane hydrocarbon species. A rapid gas chromatography (GC) instrument has been constructed to separate both the light (C2 - C4) and the midrange (C5 - C12) hydrocarbons in less than 10 minutes. The limit of detection was about 0.002 parts per million carbon (ppmC). Twelve exhaust samples from two vehicles were analyzed to compare the rapid GC method with the standard GC method, which required 40-minute analyses on two different instruments. Speciation and reactivity data from the two methods were comparable. The increased sample throughput of rapid GC promises to improve OFP and SR measurements, particularly when good statistical data are necessary to insure accurate, precise results for low emission vehicles

In this paper, the development of random vibration testing schedules for durability design verification of engine mounted products is presented, based on the equivalent fatigue damage concept and the 95th-percentile customer engine usage data for 150,000 miles. Development of the 95th-percentile customer usage profile is first discussed. Following that, the field engine excitation and engine duty cycle definition is introduced. By using a simplified transfer function of a single degree-of-freedom (SDOF) system subjected to a base excitation, the response acceleration and stress PSDs are related to the input excitation in PSD, which is the equivalent fatigue damage concept. Also, the narrow-band fatigue damage spectrum (FDS) is calculated in terms of the input excitation PSD based on the Miner linear damage rule, the Rayleigh statistical distribution for stress amplitude, a material's S-N curve, and the Miles approximate solution.

A new advanced ceramic material (ACM) has been developed and examined for diesel emission control systems, especially for diesel particulate filter (DPF) applications. Lab tests have shown that ACM possesses suitable mechanical and chemical properties for a durable DPF. Engine dynamometer tests have shown that a DPF made from ACM possesses high performance in the key application requirements of high filtration efficiency, low filtration back pressure, fast regeneration, and suitability for catalyst coating applications. The experimental results from this investigation demonstrate that a DPF made from ACM can be used for advanced diesel PM emission control systems, including potential four-way diesel catalytic converter systems.