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The fossil fuel consumption and the related environmental impact are important issues for the world research community: hydrogen seems to be a good alternative to fossil fuels provided that it is produced from renewable energy sources. The aim of the present work is the comparison between natural gas and a hydrogen-natural gas blend (HCNG in the following) in terms of exhaust emissions and fuel consumption. A passenger car has been tested on a chassis dynamometer according to the European emission regulations, without any change on engine calibration (i.e. spark advance). The HCNG blend used during the test has a 12% vol. of hydrogen content. CO emissions showed a reduction of about 19% when HCNG blend is used, while HC emissions remained constant. A 70% increase was observed for NOx emissions with HCNG. A 3% reduction for CO2 emission was observed using HCNG because of the lower carbon content in the blend and the reduced fuel consumption on a mass basis.

Electronic navigational systems allow drivers to receive travel directions while driving, rather than preplanning a route. This additional attentional load on drivers might prove to be hazardous -- particularly for older adults who have greater difficulties multitasking and switching their attention between different parts of the visual field. A driving simulator was used to evaluate the perception time to critical events in the presence and absence of a navigation system with young (n=18, age=18.8years SD= 0.7years) and older drivers (n=15, age=73.1years, SD=6.1years). The results of this study indicated that though older drivers were slower to react to critical events, and both groups were faster to react to pedestrian incursions than sudden light changes, messages from the travel system did not interfere significantly with perception reaction time in either group.

In our view the impact of software engineering technology on aircraft design methodology is often not recognized by the aircraft design community. Therefore new software engineering technology is often not used and therefore a new aircraft design methodology cannot emerge. We analyze the conventional aircraft design methodology, the design systems used to realize this methodology and the software engineering technology used to realize the aircraft design systems. We present the limitations of the conventional aircraft design methodology and explain how this is effected by the conventional software engineering technology. We then present a new aircraft design methodology and explain the impact of new software engineering technology on its realization. This analysis explains how new engineering information needs differ from the capabilities provided by the conventional information systems as applied to conceptual aircraft design.

This paper describes a limited scientific study to compare the levels of workload experienced by pilots flying the Boeing 767 and 737 aircraft. The in-flight assessment technique involves recording the pilot's heart rate to augment his subjective impressions of workload using a ten-point rating scale. Todate, data from three pilots tend to support the prediction that levels of workload on the 767 are lower than on the 737.

New transportation systems will affect living patterns in the future. Past experience indicates three principles: The availability of new transportation facilities generates new travel; commuting time has remained constant while commuting distances have steadily lengthened; population and industry locate where transportation is available. Examples substantiate each principle. Government policy has replaced terrain and geography in determining the location of transportation facilities. The implementation of multi-modal planning is necessary. Changes in all modes of transportation will occur.

Propeller noise is largely dependent upon tip speed and a reduction of this inevitably leads to either performance or weight penalty. A new aerofoil section has been developed which permits blade loading to be increased. Thus, slower revving propellers can be designed without degrading the performance or imposing a weight penalty. The paper introduces the characteristic differences in performance of the new section with more conventional ones and looks at the design of a range of propellers to illustrate the trade between noise, performance and weight with each type.

Despite massive research efforts carried out by racing car manufacturers aerodynamics is probably the most unexplored field in the design of high performance vehicles. Scale wind tunnel testing is still the most effective way for the development of a new car, CFD codes being at the experimental stage. Wind tunnel engineers produce what is called an “aero map”: a simple graph expressing aerodynamic forces versus ride height. That means, drag, downforce, and relative distribution are measured on an array of front and rear different ride heights. The same concept can be applied to track testing with the use of proper sensors on the real vehicle, such as ground height laser sensors and suspension force transducers. Reading such a map and relating it to static and dynamic suspension characteristics is a vital task for performance optimisation.

In this study, fuel octane number boosters such as toluene, ethanol, methanol, 2-methylfuran (MF), and 2,5-dimethylfuran (DMF) are blended with primary reference fuels (PRFs) in a cooperative fuel research (CFR) engine at research octane number (RON) relevant conditions. In addition to RON determination, engine operation is characterized by measuring (i) cylinder, intake and exhaust pressure, (ii) averaged intake and exhaust temperature, and (iii) air-fuel-ratio. For known fuel blends, the measured RON corresponds well with existing literature. The addition of MF in PRF yields a significant increase in RON and blending octane numbers (indicating booster impact) up to 216. Cylinder pressure fluctuations, the classical definition of knock intensity, are however not consistent, deviating between PRFs and all boosted blends at higher RON values. Moreover, some fuel blends exhibit scarcely any knocking behavior in the test conditions.

Off-shore sourcing poses a double threat to U.S. suppliers of original equipment and aftermarket components for domestically produced automobiles. U.S. suppliers will lose not only the sale of the components going into the new vehicle, but are quite likely to lose the aftermarket for these parts as well. Today, foreign-built components represent less than ten percent of the cost to build an average American car. By the early 1990's, the U.S. vehicle makers are predicting that the off-shore components will represent roughly 30 percent of that cost. This paper reports the results of exercising a computer model of the U.S. aftermarket to analyze the predicted impact of this off-shore sourcing on the original equipment suppliers' aftermarket business.

The pressing problems of exhaust emissions legislation on diesel engine manufacturers are well known. A great deal has been written on the engineering modifications necessary so that engines coming onto the market after 1994 meet the relevant emissions standards. Almost certainly engine lubricants will have to be reformulated to meet the increased severity resulting from the modifications. However, there is another aspect to this issue which is seldom discussed, and that is the direct influence of the lubricant on the composition of the exhaust emissions. This paper describes experiments conducted over several years to understand the contribution that the lubricant can make to reducing emissions of NOx and particulate. The first section focuses on how both the physical properties and chemical composition of the lubricant have a role to play in reducing emissions. It then describes the development of a protoype low emission oil.

Post-injection strategies prove to be a valuable option for reducing soot emission, but experimental results often differ from publication to publication. These discrepancies are likely caused by the selected operating conditions and engine hardware in separate studies. Efforts to optimize not only engine-out soot, but simultaneously fuel economy and emissions of nitrogen oxides (NOx) complicate the understanding of post-injection effects even more. Still, the large amount of published work on the topic is gradually forming a consensus. In the current work, a Design-of-Experiments (DoE) procedure and regression analysis are used to investigate the influence of various operating conditions on post-injection scheduling and efficacy. The study targets emission reductions of soot and NOx, as well as fuel economy improvements. Experiments are conducted on a heavy-duty compression ignition engine at three load-speed combinations.

To enhance the “Energy Conserving” (EC) performance of crankcase engine oils, the friction reducing capabilities of several oil-soluble organomolybdenum (OM) compounds were evaluated in formulations containing different base oils and viscosity index improvers (VIIs). Using a Cameron-Plint TE 77 Reciprocating Friction Machine, operating under boundary lubrication conditions, OM additives reduced friction coefficients by almost 80%. Frictional force reductions were sensitive to temperature and the apparent “solvency” of the base oil employed in the formulation. Optimum performance was generally observed in base oils of “poorer” solvent quality (high Viscosity Index or high saturate content) or in conventional mineral oils at temperatures above 100°C.

The effect of adding Oxygenates to the fuel, on exhaust emissions and fuel consumption, was evaluated. Chassis dynamometer tests (ECE + EUDC) were carried out on six petrol cars. Three of the cars were fitted with three way catalysts. The fuels had been oxygenated by adding 10 % MTBE, 15 % MTBE, and 5.2 % Ethanol. Test results show that oxygenates in the fuel reduce emissions and fuel consumption. Of the fuels investigated, addition of 15 % MTBE gave most benefits with the following reductions in emissions:- CO: 15 - 30 %, NOx: 1.3 - 1.7 %, THC: 10 - 20 %, CO2: 1.0 - 4.0 %, Reductions in fuel consumption with 15 % MTBE were 1.3 - 1.7 % for non catalyst cars and 3.2 - 5.2 % for catalyst cars.

A 100,000-mile fleet test in nine gasoline-powered passenger cars was carried out. The impact of motor oil phosphorus levels on engine durability, oil degradation, and exhaust emissions has been previously described. The results of additional emissions control systems studies, and measurements of the engine oil additive elements which are present on the catalysts, are now presented. These studies include conversion efficiencies for the aged catalyst at the end of the test by a combination of light-off experiments, air/fuel sweep tests, and an auto-driver FTP. The performance of the lambda sensors is also presented. The relationships between engine oil additive levels and composition and emissions systems durability is presented.

A 100,000-mile fleet test was carried out on nine 1991 gasoline-powered passenger cars employing an API SH/CD motor oil and two reduced phosphorus analogues. The lower-phosphorus oils have zinc dialkyldithiophosphate (ZDDP) treat rates that fall below the proposed ILSAC GF-2 maximum phosphorus limit (0.11%). Gaseous tail pipe emissions were measured at various intervals according to the EPA FTP City Emissions Test 75 driving cycle. A good correlation between phosphorus level and emissions degradation was obtained when starting emissions levels and oil consumption was accounted for in the analysis. Few differences were observed between the highest-phosphorus oil (0.11%) and the lower-phosphorus (0.08% and 0.06%) oils in the typical end of test engine cleanliness parameters. There were no significant differences in either valve train or cylinder wear between the oils. The used oils had similar analytical inspections.

Throughout the evolution of the automobile, passenger car motor oils have been developed to address issues of wear, corrosion, deposit formation, friction, and viscosity stability. As a result, the internal combustion engines are now developed with the expectation that the lubricants to be used in them will deliver certain performance attributes. Metallurgies, clearances, and built-in stresses are all chosen with certain expectations from the lubricant. A family of chemicals that has been universally used in formulating passenger car motor oils is zinc dithiophosphates (ZDPs). ZDPs are extremely effective at protecting highly stressed valve train components against wear failure, especially in engine designs with a sliding contact between cams and followers. While ZDPs' benefits on wear control are universally accepted, ZDPs have been identified as the source of phosphorus, which deactivates noble metal aftertreatment systems.

Sealing applications in electrified vehicle powertrains present a unique set of boundary conditions when contrasted with typical transmission or internal combustion engine applications, including changes in fluidic exposure, operating pressure, temperature profiles, etc. This novel powertrain environment opens the gasket material spectrum to elastomers uncommon in standard powertrain joints, which allows for more optimized, higher-value sealing solutions. However, this also introduces new risks, including the risk of excessive compression set in silicone elastomers due to acidity in adjacent plastics (which can result from shifting to non-halogenated flame retardants from halogenated flame retardants). To understand this phenomenon, compression set testing was conducted with plastic resins ranging from pH = 3.4 to pH = 7.3 and three high-consistency rubber (HCR) silicone elastomers.

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.