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The efficiency and emission potential of pre-chamber combustion in a Miller cycle light duty gasoline engine operated under part load was evaluated. Several pre-chamber designs that examine the engine performance tradeoffs with nozzle diameter, pre-chamber volume, number of nozzles, and pre-chamber fuel enrichment were investigated for both excess air and cooled external EGR dilution strategies. The introduction of pre-chamber jet ignition was observed to significantly reduce the main-chamber combustion duration while reducing cyclic variability under dilute conditions, benefiting from the long-reach ignition jets and enhanced turbulence. However, the pre-chamber design that provided the fastest combustion led to reduced brake efficiency primarily due to increased wall heat loss. Maintaining the total nozzle area while increasing the number of nozzles was identified as a means to minimize the additional heat loss and maintain fast burn rates.

The effect of increased pressure relevant to pre-turbine catalyst positioning on catalytic oxidation of methane over a commercial Pd-Pt model catalyst under lean conditions is investigated both experimentally and numerically. The possible gas phase reactions due to high temperature and pressure were tested with an inert monolith. Catalyst activity tests were conducted for both wet and dry gas mixtures and the effect of pressure was investigated at 1, 2 and 4 bar. Aside from the water in the inlet stream, the water produced by oxidation of methane in dry feed inhibited the activity of the catalyst as well. Experiments were carried out to check the effect of added water in the concentration range of water produced by methane oxidation on the catalyst activity. Based on the experimental results, a global oxidation rate equation is proposed. The reaction rate expression is first order with respect to methane and -1.15 with respect to water.

Because of the adverse effect that product liability litigation has had on the aviation community, the Aircraft Owners and Pilots Association has formed the Coalition for General Aviation Liability Reform, along with other consumer-interest organizations, to ensure proper consideration is given to the health of the aviation community, the cost and availability of aviation products, and to the development of an improved victim-compensation program. Although initial consultation with the general aviation manufacturers and legislators has left both sides equally satisfied, this paper will explain why more work is recommended to further refine present legislation and to press for its enactment.

The need for a uniform federal standard for product liability in General Aviation is presented in light of the current experience with state-by-state tort law. This presentation is concerned mainly with safety, why manufacturers emphasize safety, how safety is improved, related FAA regulations, and the downward trend of fatal aircraft accidents. In contrast to this is the impact of product liability litigation from a General Aviation aircraft manufacturer's viewpoint.

Product liability has had a pronounced effect on entrepreneurial businesses such as are found in the aviation industry. One of the main impacts is due to legal game playing which is done solely for the purpose of finding a source to pay damages irrespective of real fault. This legal game playing threatens to curtail innovation and invention and slow the progress of aviation development.

Recently, global warming and energy security have received significant attention. Thus an improvement of the vehicle fuel economy is strongly required. For engines, one effective way is to improve the engine thermal efficiency. Raising compression ratio [1] or turbo charging technologies have potential to achieve high thermal efficiency. However knock does not allow the high thermal efficiency. Knock depends on the fuel composition and the pressure and temperature history of unburnt end-gas [2-3]. For fuels, RON is well known for describing the anti knock quality. High RON fuels have high anti knock quality and result in higher thermal efficiency. This paper investigates the impact of high RON fuels on the thermal efficiency by using high compression ratio engine, turbo charged engine, and lean boosted engine [4]. Finally, it is shown that the high thermal efficiency can be approached with high RON gasoline and ethanol.

Driving schedules prescribed for fuel-economy regulation are composed of two generic modes: (1) accelerations and constant-speed travel, requiring a positive tractive force at a vehicle's driving wheels; (2) decelerations, requiring a negative or braking force at those wheels. In the first mode, a total tractive energy, ETR, is required to overcome a vehicle's tire rolling resistance, aerodynamic drag, and the inertia of its mass. In the second mode, all the kinetic energy that a vehicle's mass acquired in the first mode has to be removed. The inherent rolling resistance and aerodynamic drag remove some of it. The remainder, EBR, has to be removed by a wheel-braking force. In vehicles with conventional braking the wheel-braking force is frictional, and so all of EBR is dissipated. However, if this force is not inherently frictional some of EBR can be captured, stored, and subsequently used to provide part of the ETR required for propulsion.

This paper presents the results of an in-use emissions testing program which investigated the emissions and duty cycles from five heavy-duty construction vehicles. The program examined the emission reduction potential of various retrofit control technologies including; diesel oxidation catalysts, passive particulate filter, and active particulate filter technologies. Analysis of the results are provided for both the original vehicle configuration and with the vehicles retrofitted with exhaust aftertreatment systems. The vehicles studied included a dump truck, two wheeled loaders, a backhoe and a bulldozer. The paper will discuss in-use heavy-duty vehicle emissions and the use of emissions control technologies.

China has become the world’s largest vehicle market in terms of sales volume. Automobiles sales keep growing in recent years despite the declining economic growth rate. Due to the increasing attention given to the environmental impact, more stringent emission regulations are being drafted to control traditional internal combustion engine emissions. In order to reduce vehicle emissions, environmentally-friendly new-energy vehicles, such as electric vehicles and plug-in hybrid vehicles, are being promoted by government policies. The Chinese government plans to boost sales of new-energy cars to account for about five percent of China’s total vehicle sales. It is well known that more electric and electronic components will be integrated into a vehicle platform during vehicle electrification.

Sound absorption for multiple materials was measured in a small reverberation room using different sample sizes. The largest samples were cut to progressively smaller sizes to study the effect of sample size on sound absorption. The materials tested included three different recycled fibers, two PET fibers with facers, and one open-cell foam. These materials spanned low, medium, and high sound absorption over the range of test frequencies. The results for each material and each sample size are reported and compared. Comments are provided on sample size for labs with small reverberation chambers. These results will be considered in the development of an SAE test method for sound absorption using small reverberation rooms.

Diesel fuels usually comprise a wide range of compounds having different molecular structures which can affect both the fuel's physical properties and combustion characteristics. In future, as synthetic fuels from fossil and sustainable sources become increasingly available, it could be possible to control the fuel's molecular structure to achieve clean and efficient combustion. This paper presents experimental results of combustion and emissions studies undertaken on a single cylinder diesel engine supplied with 18 different fuels each comprising a single, acyclic, non-oxygenated hydrocarbon molecule. These molecules were chosen to highlight the effect of straight carbon chain length, degree of saturation and the addition of methyl groups as branches to a straight carbon chain.

A new wheel end concept was designed and developed to allow sport utility vehicles (SUV) and light trucks the possibility of achieving a negative scrub radius. This paper will compare a production vehicle with a scrub radius of 54.8 mm with the same vehicle modified with several alternate scrub radii. The vehicle changes are completed in a way that still packages the brake components and meets the component durability needs of a light truck wheel end load cycle. Quantitative vehicle computer analysis and actual instrumented vehicle performance data will be compared and correlated to analyze the effects of scrub radius.

The additive chemistry of some gear lubricants can have a major impact on the surface durability of rolling element bearings (1). Lubricant formulation has been slanted heavily toward protecting gear concentrated contacts from galling and wear. As such, much of the performance differentiation of lubricants has been dependent on highly accelerated, standardized laboratory tests related to gears. Methods have been proposed to evaluate and quantify a lubricant's performance characteristics as they relate to rolling element bearings (2). Results from several lubricant performance evaluations are presented. The implications of these findings suggest that the detrimental performance effects on rolling element bearings need further fundamental study by the lubricant industry.

An operational scheme with fuel-lean and exhaust gas dilution in spark-ignited engines increases thermal efficiency and decreases NOx emission, while these operations inherently induce combustion instability and thus large cycle-to-cycle variation in engine. In order to stabilize combustion variations, the development of an advanced ignition system is becoming critical. To quantify the impact of spark-ignition discharge, ignitability tests were conducted in an optically accessible combustion vessel to characterize the flame kernel development of lean methane-air mixture with CO₂ simulating exhaust diluent. A shrouded fan was used to generate turbulence in the vicinity of J-gap spark plug and a Variable Output Ignition System (VOIS) capable of producing a varied set of spark discharge patterns was developed and used as an ignition source. The main feature of the VOIS is to vary the secondary current during glow discharge including naturally decaying and truncated with multiple strikes.

A commercial NOx-storage catalyst for gasoline applications containing Ba/CeO2/Al2O3, platinum, palladium and rhodium has been sulfated on the engine bench at 390 and 510°C with a nominal exposure of 1.3 g sulfur/liter catalyst. Lower exposures proved too low to have a notable impact on the catalytic performance. At 390°C the sulfur is completely adsorbed while at 510°C only partial adsorption is being observed. Sulfur is mainly deposited at the catalyst inlet thereby shielding the downstream region. Desulfation on synthetic gas bench at 700°C leads to a partial removal of the sulfur. The residual sulfur is more evenly distributed along the length of the catalyst compared to the sulfur profile in the sulfated catalyst. This causes an improvement of the NOx-activity at the inlet side while the NOx-performance at the outlet side decreases after desulfation.

Pelleted and monolith three-way catalysts were treated in a laboratory reactor under conditions closely simulating automobile exhaust and then characterized using x-ray photoemission and temperature programmed desorption techniques to determine relative amounts and oxidation states of sulfur stored by the catalyst. Sulfur originating as SO2 in the feed was stored on the support component of both catalysts in the form of adsorbed sulfates and sulfites and on the noble metals in the form of elemental sulfur. The monolith catalyst stored a greater amount of sulfur and equilibrated more rapidly with the sulfur content in the feed than did the pelleted catalyst. Operation in a rich environment removes sulfur from the support components, while operation in a lean environment removes sulfur from the noble metal surfaces. This behavior is consistent with the observation that sulfur inhibits three-way activity in a rich environment.

The relationship between H2S emissions from three-way catalysts and the storage of sulphur on the catalyst surface has been investigated. Thermodynamic data predict that sulphur storage primarily will occur on Al2O3 and CeO2 under lean and stoichiometric conditions, at up to 500°C. Rich transients could then induce the decomposition of the Ce-S-O and Al-S-O compounds, releasing sulphur into the gas phase. Experimental studies have supported this model. A mechanism has been proposed for the subsequent formation of H2S. The mechanism by which catalyst poisons attenuate H2S emissions from engine-aged catalysts also has been studied. The effect has been shown to be related to decreased storage of sulphur, caused by stable catalyst-poison species at the catalyst surface.

Engine mounting system maintains the position of powertrain in the vehicle with respect to chassis and other accessories during inertia, torque reaction loads and roadway disturbances. The mounting system also plays a role in terms of isolation of the rest of the vehicle and its occupants from powertrain and helps in maintaining vehicle ride and handling condition. This paper investigates the performance comparison between hydromount and switchable hydromount during idle and ride performance. The optimization scheme aims to improve the performance of the mounting system in order to achieve overall powertrain performance and NVH attribute balancing through switchable mount technology.

The electric vehicle in the past several years has developed into a basically reliable alternative to petroleum-dependent vehicles for certain fleet missions. The use of the electric vehicle thus far has, in fact, stimulated interest in exploring the practicality of the electric vehicle for extended range missions. General Telephone & Electronics has assessed the potential technological and economic advantage of Gulf+Western Industries, Inc. zinc-chloride battery and, based on recent tests of our vehicle and modification to mechanical design of the battery to suit vehicles being used by GTE fleet operators, will introduce three 750 pick-up trucks equipped with the zinc-chloride battery into its Pomona, California fleet during this year. This paper addresses modifications made to the battery design, test results, projected performance and potential economic impact.

Technology integration studies were made to examine the impact of emerging technologies on fighter aircraft. The technologies examined included advances in aerodynamics, controls, structures, propulsion, and systems and were those which appeared capable of being ready for application by the turn of the century. A primary impetus behind large increases in fighter capability will be the rapid increase in fighter engine thrust-to-weight ratio. High thrust-weight engines, integrated with other advanced and emerging technologies, can result in small extremely maneuverable fighter aircraft that have thrust-weight ratios of 1.4+ and weight one-half as much as today's fighters. Future fighter aircraft requirements are likely to include a turn capability in excess of 7g's throughout much of the maneuver envelope, post-stall maneuverability, STOVL or VTOL, and a single engine for low cost.