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This work addresses and evaluates the likelihood of human casualty in highway crashes, projected on the basis of field crash data that may become available electronically by sensors at crash time, and/or observed at the crash scene by emergency attendants. Termed collectively as a “crash signature”, such data are treated as predictors and are selected from: crash severity, general area of damage, direction of force, occurrence of rollover, intrusion, vehicle crush and its specific horizontal location, collision partner, vehicle class and size, occupant age, gender, restraint use and type, seating position, and other. Crash signatures are converted into responses such as: (a) the likelihood of the most severe outcome, fatality or survived injury, by severity AIS per occupant; and (b) the same per vehicle. Cars are the vehicles selected for this investigation.

The first single-piece, rear bumper system injection molded from an engineering thermoplastic provides 8 km/h pole impact as well as required Federal Motor Vehicle Safety Standard (FMVSS) protection requirements for a small passenger vehicle. The system's efficient design features integral fascia support, eliminating bracketry and providing assembly savings at the plant. The bumper offers a 1.5 kg mass savings compared to conventional aluminum and polypropylene foam bumper systems. Additionally, its low intrusion design means neither the rear end panel nor the deck lid was damaged at the 8 km/h impacts tested. This paper will describe the bumper's design, development, and validation process, plus describe the results achieved to date.

Developed specifically for the automotive industry, a new glass-mat thermoplastic (GMT) composite technology provides significant improvements in strength and energy management behavior for automotive bumper applications. This increased performance is achieved through the use of new fiberglass mat design, sizing chemistry, and binder resin technology vs. standard GMT composite products with the same type and percentage of glass loading. No substantial tooling and processing changes are required to make use of the new products, which are interchangeable in current GMT molds. In order to fully evaluate the new materials, actual direct-mountable automotive bumper beams were molded and tested in both static and dynamic modes. The results of this testing demonstrate the new composites' ability to achieve Federal Motor Vehicle Safety Standard (FMVSS) 581 8 km/h impact performance without the need for costly hydraulic or foam energy absorption (EA) units.

The commercial validation of a optimized RRIM polyurethane substrate with a novel barrier coat for fascia applications is reviewed which creates cost competitiveness to thermoplastic olefins (TPO), without sacrificing performance. Meeting fascia performance requirements with thinner and lighter RRIM materials containing recyclate and the subsequent application of a barrier coat eliminating the traditional primecoat cycle was investigated.

Microfibers with high specific micro-surface can be knitted into two-dimensional structures with large internal porosity. Catalytically active metals can be deposited on the fibers with high dispersion by wet-impregnation, sol-gel or CVD, respectively. These microfiber knits may be used for exhaust gas treatment systems with a triple function: particle filtration, gas conversion and muffling. The total oxidation of propane on Pd and Pt coated fibers has been studied as a test reaction. Conversion temperature could be remarkably reduced compared to cellular structures. For a bimetallic (Pt-Pd) coating, the activity is independent of humidity or oxygen concentration. Thus a catalytic converter based on micro-fiber knits appears feasible. Its high mass and heat transfer prevent hot spots. And it functions as submicron filter for combustion aerosols. Integrated electric heating can also be provided in case of low gas temperatures. First tests on engines show promising results.

Diesel engines are irreplaceable in tunnel construction. The particulate emissions of present day engines are so high that the imission limits valid since 1991 cannot be attained by ventilation alone. This problem had to be solved preparatory to the large tunnel projects in Switzerland, Austria and Germany. Several retro-fitting measures were investigated both in the laboratory and in field tests, within the scope of the Project VERT. Oxidation catalytic converters, exhaust gas recirculation, and the usage of special fuels cannot be recommended. Particulate trap deployment, in different systems, was mostly successful. Particular attention was focused on the dependable filtration of finest particulates < 200 nm. The VERT proved that exhaust gas after-treatment with particulate traps is feasible, cost effective and controllable in the field. Pertinent directives are in discussion.

New developments for optimized control of Aerodynamically Regenerated Traps (ART) - Exhaust Gas Recirculation (EGR) integrated systems for diesel engines are presented herein. Such systems employ high-efficiency ceramic monolith filters to retain 99% of the emitted particulates. Regeneration is achieved periodically by short pulses of compressed air, flowing in the opposite direction to the exhaust. The soot is collected in a chamber, outside of the monolith, where it is oxidized with an electric burner. A fraction of the filtered exhaust is returned to the engine and this reduces NOx emissions, typically, by more than 50% at 18% EGR. However, since the amount of EGR, the frequency of regeneration and the frequency and duration of burning have a bearing on the fuel consumption of the engine, their optimization is imperative. Thus, provisions were made to collect intelligent information, leading to continuous assessment of the engine performance and fuel economy.

A particulate aggregate model which takes place during the incomplete combustion of Diesel1 fuel in heavy duty engines is presented. An approximate analytical solution for the temperature field in a filter ceramic porous wall is presented. An alternative approach covering essential engineering problems is presented by means of a numerical simulation, which shows safety operational features of the proposed scheme. Some predicted performance of the filter ceramic traps are also presented.

In order to reduce the amount of particulate matter (PM) in the exhaust gas of diesel engines, a dual flow type diesel particulate filter (DPF) system made of porous metal filters has been developed. In this paper, the development and the evaluation results will be discussed. The test results on the engine bench and the vehicle have revealed good performance of the DPF system and have practical application for urban buses.

The design of a diesel particulate trap system to fit a specific vehicular application requires significant expenditure, due to the high degree of interaction between the vehicle operation and trap behavior. The assistance of modeling in the design process is already well established. This paper presents the basic principles of a Computer Aided Engineering methodology aimed to assist the selection of the basic parameters of a Diesel Particulate Trap System by reducing the number of the necessary experimental tests. The computational modules currently supporting the CAE methodology are based on fundamental mathematical models, incorporating a small number of semi-empirical relations derived by experimental data on trap loading and catalytic regeneration, exhaust system heat transfer and trap backpressure effect on fuel consumption.

The paper presents a 2-dimensional model for the calculation of the regeneration process in a wall flow diesel particulate filter. The model includes heat transfer by conduction and convection, a model for particle combustion based on diffusive burning of individual particles, and flow through the channels and across the filter walls. It was found that only the pressure drop across the walls need be considered for normal regeneration conditions. Comparisons between model predictions and experimental results for spatial dependent temperature time histories, and integrated degree of regeneration are used to validate the model. The validations were carried out for a series of severe regenerations, where there are large changes in flow and temperature throughout the process. Relative magnitudes of energy flows due to combustion, convection, and conduction are presented, as well as parametric studies of the effects of temperature, oxygen concentration and soot loading.

In the last years the development of diesel particulate traps and trap regeneration systems has led to some very promising concepts. In parallel the development of diesel engine technology for passenger cars, as well as for light and heavy duty vehicles, has resulted in remarkable improvements especially regarding particulate and NOx emissions, engine performance and fuel economy. Unfortunately, for some aspects the development and application of particulate trap systems on the one hand and diesel engine technology on the other have led to conflicting solutions. For example, exhaust gas temperatures of at least 500 °C to 600 °C are necessary to burn off the soot that has been emitted by the engine and collected in a particulate trap. However, the increased fuel efficiency of modern TDI diesel engines and the trend to reduced average traffic speed very often cause exhaust temperatures below 200 °C at urban driving conditions.

A ceria stabilised zirconia supported Pd/Zn catalyst (Pd/Zn ratio=1:2) has demonstrated its ability to perform as a three-way catalyst (TWC) and to give conversions of up to 99% of a stoichiometric mixture of carbon monoxide/npropane/nitric oxide/dioxygen in dinitrogen carrier at a WHSV of 44,000 h-1. The catalyst also exhibits excellent thermal stability inoxidising conditions. Characterisation of the catalyst has been performed using XRD, XPS, BET,and DSC. From this it has emerged that the palladium is in a highly dispersed state, closely associated with the zinc phase. In situ kinetic studies have also been conducted under continuous flow conditions.

Diesel engines are coming under stricter requirements to reduce emissions. particularly those of particulates and nitrogen oxides (NOx). Recently, the U. S. EPA put into place staged requirements for heavy duty diesel engines in urban bus applications which are aimed at ultimately bringing pre-1994 engines into particulate emissions compliance with 1994 heavy duty on-road truck standards (0. 1 g/bhp-hr TPM). This reflects the need to control emissions in crowded urban environments. Zirconia based ceramic combustion management coatings, although originally developed for adiabatic or low heat rejection engines to boost thermal efficiency, have also been shown to contribute to the reduction in diesel emissions. Heavy duty transient testing of rebuilt 2-stroke MUI diesel bus engines equipped with stabilized zirconia based coatings applied by thermal spray process have shown significant reduction in exhaust opacity relative to a baseline, uncoated engine.

Three-way conversion (TWC) catalyst supports were prepared having CeO2-ZrO2 solid solution particles uniformly dispersed on γ-Al2O3 as discrete crystallites. The support morphology was characterized using STEM and TEM analysis. TPR and XRD analyses were also carried out on precious metal (PM) containing and PM-free samples before and after aging. These studies were combined with performance measurements which demonstrated the beneficial effects of solid solution formation on TWC catalyst activity. STEM and TEM analysis showed that well-dispersed CeO2-ZrO2 solid solution particles could be formed and simultaneously supported on a high surface area γ-Al2O3 support. For samples calcined up to 600°C, crystallite sizes of ≤50Å were formed as compared to sizes of over 200Å in the aged samples. The TPR studies suggested that for supports calcined up to 600°C most of the CeO2 present was reduced from the Ce4+ to the Ce3+ state in the temperature range 250 - 700°C.

Current major concerns m auto exhaust three-way conversion (TWC) catalyst are: 1) improved thermal stability for high temperature applications, such as low emission vehicles (LEV), and 2) high O2 storage capacity for on-board diagnostic (OBD) systems to meet OBD-2 regulations. These are challenges to catalyst technologies posed by the regulations. Of the many possible approaches, stabilization of Rh and CeO2 by ZrO2 shows promise in TWC formulations. This paper summarizes our investigations of thermally stabilized Zr containing TWC catalysts, including the chemistry of CeO2 stabilization with ZrO2, and their OBD-2 characteristics.

Zirconium dioxide (zirconia) is a well-known material often being a major component in the washcoat systems of three-way catalysts (TWC) and diesel oxidation catalysts. One important characteristic of zirconia containing washcoats is an improved aging stability which is required to meet the more and more stringent emission standards. In the last few years the utilization of zirconia became even more important - especially for high sophisticated three-way washcoat systems. This was due to the development of high temperature stable oxygen storage components, containing cerium dioxide (ceria) in combination with different other oxides - one very promising candidate being zirconia. In the present work the results of a research program are discussed, focusing on the influence of zirconia in combination with ceria and additional rare earth promoters on the stability of the oxygen storage characteristics.

Vibration and noise are generally considered to be the major problems in power transmission chains. This paper presents an adaptive, active control strategy for the reduction of vibration in automotive timing chain drives and examines the effects of the active control on noise reduction. Experimental results show that the average vibration amplitude is diminished by as much as 90% under low to moderate tension conditions, and the chain noise is reduced by about 3 dB. The experimental apparatus has low cost and is readily applicable to an industrial environment.

Compression in the head-neck complex often causes fractures of the first cervical vertebra (C1). The type of fracture often determines whether the injury is stable or unstable, which significantly affects the ultimate injury severity. The often unstable bursting fracture of C1 is thought to be caused by a transformation of axial compressive forces into lateral bursting forces by the wedge-shaped lateral masses. The purpose of this study was to measure the orientation of the joint surfaces of C1 to determine whether this symmetry exists. An additional goal was to determine whether the orientation of the joint surfaces varied significantly with location on the surface. Direct measurements of surface coordinates were taken from 40 dried vertebrae. The angles of two areas on each of the four joint surfaces of the lateral masses of C1 were then calculated. The resulting angles agreed with previous investigations of upper cervical vertebral anatomy.

After a rear end impact, various clinical symptoms are often seen in car occupants (e.g. neck stiffness, strain, headache). Although many different injury mechanisms of the cervical spine have been identified thus far, the extent to which a single mechanism of injury is responsible remains uncertain. Apart from hyperextension or excessive shearing, a compression of the cervical spine can also be seen in the first phase of the impact due to ramping or other mechanical interactions between the seat back and the spine. It is hypothesized that this axial compression, together with the shear force, are responsible for the higher observed frequency of neck injuries in rear end impacts versus frontal impacts of comparable severity. The axial compression first causes loosening of cervical ligaments making it easier for shear type soft tissue injuries to occur.