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The formulation of injection moldable thermoplastics with small loadings of graphite nanotubes provides sufficient conductivity in molded parts to allow for use in electrostatic painting applications. Normally, plastic parts need to be painted with a conductive primer prior to the electrostatic painting of base and clear coats. The use of conductive plastics eliminates the need for the priming step, and improves paint transfer efficiency and first pass yield. These elements provide obvious savings in materials and labor. What is less obvious, however, is the dramatic positive environmental impact that can occur through the reduction in emissions of volatile organic compounds (VOCs). Graphite nanotube technology provides advantages over other technologies such as conductive carbon black. In order to reach the percolation threshold for conductivity in carbon-black-containing resins, the loading of carbon black required tends to embrittle the polymer.

Design and implementation of predictive service life performance tests also referred to as “Key Life Tests” are vital to the automotive industry to control warranty costs, track the quality of materials and processes, and in the specification of new materials systems. In addition to these roles, key life tests offer valuable insights into relating design features to performance and serving as tools to predict durability. A systems approach to assess durability of painted automotive exteriors subject to various tribological loading conditions is presented in this paper. This approach blends fundamental phenomenological understanding with real world usage “metrics” in order to implement laboratory simulations. To the authors knowledge, this is the first time, a synthesis of tribological principles and systems theory have been made for designing and implementing key life tests for paint durability. Several examples have been included to bring out the power of this approach.

The purpose of this paper is to investigate 2 issues involving the use of hollow-glass microspheres in sheet molded compound (SMC): 1) demonstrate the value of using volume fraction over weight fraction formulating to evaluate materials with significantly different densities and 2) directly compare physical property data of low density SMC to standard density commercially available SMC. The primary benefit of using hollow-glass microspheres in SMC, for the automotive industry, is reducing the weight of SMC parts.

Various toughness properties were compared between long-glass-fiber-reinforced thermoplastics and their short-fiber counterparts in an effort to understand the toughening mechanisms of the long-glass fibers in reinforced thermoplastics. It was found that long-glass fibers improve the toughness of polypropylene- based composites by rendering more resistance to fiber debonding and subsequent pull-out, especially at subambient temperatures. For nylon-based composites, which form strong fiber/matrix interfaces, long-glass fibers were found to increase the toughness by imparting more resistance to fiber breakage. Finally, fiber orientation was found to have a significant effect on the fracture toughness of reinforced thermoplastics.

Conductively modified thermoplastic olefins (TPOs) have been developed using low levels of conductive carbon fillers, <6 wt.%, without sacrificing the favorable mechanical and rheological properties exhibited by these materials for the automotive market. The bulk electrical properties of these materials exhibit traditional percolation behavior when the samples are compression molded. Conductively modified injection molded materials exhibit a high surface resistivity, typically greater than 1016 ohm cm, which is compensated by a relatively low resistance interior, defined as a core resistance. The threshold for electrostatic paintability has been identified based on core resistance measurements, electrostatic dissipation results, and electrostatic painting transfer efficiency data. The core resistance must be less that 109 ohm/cm for charge dissipation to occur and for any significant increase in paint film builds to be observed.

In response to the demands of today's automotive market, advancements have been made where acoustical insulation does much more than just reduce noise. Insulators are now being manufactured to precise tolerances allowing for improved value added features, while also reducing part count and simplifying assembly. In addition, methods have been developed to reduce part weight and provide a product that is fully recyclable while maintaining superior acoustical performance.

Liquid Injection Molded silicone elastomers represent a processing alternative to heat-cured silicone elastomers used in traditional compression molding processes. Higher injection speeds, cure speeds, and complex mold filling by Liquid Injection Molded materials offer rubber fabricators productivity gains that more than offset higher initial material and investment costs. However, the wide-spread acceptance of Liquid Injection Molded products in the automotive industry has been limited from a performance standpoint; up until now, Liquid Injection Molded products have not reached the level of underhood performance of heat-cured silicone elastomers in terms of heat age, compression set, and oil stability. We describe 2 breakthroughs in Liquid Injection Molded technology that will lead to much wider industry acceptance.

Design and development of the Cummins Signature 600, a new high horsepower dual overhead cam truck diesel engine, has been completed. The Signature 600 product system includes an all-new engine, controls, fuel system, and business information systems. During product definition, particular emphasis was placed on target markets, customer input to design, engineering and manufacturing processes, concurrent engineering and extensive mechanical and thermal analyses. Cummins Signature 600 fulfills the needs of Owner-Operator and Premium Fleet linehaul trucking businesses.

Diesel engines have become increasingly popular as a power unit for passenger cars over the last decade, due mainly to their superior fuel economy. The first generation of high speed direct injection engines suffered from a lack of refinement by comparison with contemporary spark ignition engines. Analysis of subjective assessments of typical diesel engine noise identified impulsive sounds and the excitation of low frequency resonances as the major reasons for adverse subjective reaction. In addition torsional resonances in the drive train can be excited by fuelling variations as a result of interactions between hydraulic waves in the fuel injection drillings and pipes (time dependent) and the pump filling and injecting events (speed dependent). Drivetrain resonances can be excited also by rough clutch engagement, road imperfections and sudden increases in fuelling in response to driver demand.

A common rail injection system was applied to port-loop and uniflow scavenged two-stroke DI-Diesel engines. While the uniflow scavenged configuration was operated with a swirl level comparable to that of 4-stroke DI-Diesel engines, no swirl motion was realized with the port-loop scavenged arrangement. The results show that, in spite of disadvantages in the mixture formation process, the high mixture formation energy observed with the common rail injection makes a swirl-free Diesel combustion possible. However, at part load the combustion process and emission level with the port-loop scavenged engine is not satisfactory. At full load, disadvantages in the scavenging process are observed in addition to the poorer mixture formation with the loop scavenged two-stroke concept. Consequently, the expected specific power output of the port-loop scavenged arrangement is with 20 kW/l far lower than about 45 kW/l predicted for the uniflow scavenged engine.

Substantial improvements in engine fuel efficiency, torque and reduction of emissions are available with camless actuation capable of continuous control of engine valve lift, duration and timing. A phenomenological model has been developed for an unthrottled operation that is key to efficiency gain. An adaptive nonlinear controller has been designed to coordinate intake valve lift and duration by using high sampling rate intake manifold pressure and flow sensors. The driver torque demand is satisfied, while pumping losses are minimized. Simulation results for a 4 cylinder 2.0 L engine demonstrate event-to-event tracking and cylinder-to-cylinder balancing. The controller corrects for variations in effective flow areas (e.g. valve deposits), induction ram effects, and temperature.

A geometrically accurate, three-dimensional finite element model of a Diesel engine exhaust valve and cylinder head assembly has been developed to analyze the effect of cylinder head interactions on exhaust valve stresses. Results indicate that a multi-lobed stress pattern occurs around the exhaust valve head due to cylinder head deformation, stiffness variations, and thermal asymmetry. Consequently, peak valve bending and hoop stresses from the three-dimensional model are 48% and 40% higher, respectively, than for the two-dimensional, axisymmetric model. These results indicate the degree of model complexity required for more accurate analyses of exhaust valve operating stresses.

A systematic methodology for combustion system optimization was formulated for the development of the new Chrysler V8 engine. The methods employed by this process correlated flow bench generated airflow and charge motion studies to dynamometer based measurements of wide-open-throttle performance, exhaust emissions, fuel consumption, and combustion stability. Selection of the optimum combustion system was based on a weighted analysis of dynamometer generated parameters.

Direct flame imaging and pressure analysis were applied to the combustion of gasoline and compressed natural gas (CNG) in a single-cylinder, four-valve spark-ignition engine equipped with optical access via quartz windows in the cylinder liner and piston crown. Tests were performed at three engine speed/load conditions and at equivalence ratios of 1.0, 0.9 and 0.8. The four-valve head incorporated two different port geometries, with and without metal sleeves to deflect the intake air flow, in order to investigate the effect of tumble strength on combustion and engine-out emissions of unburned hydrocarbons and NOx. The results showed that sleeving of the intake ports produced a significant increase in IMEP and a reduction in CoV IMEP for both CNG and gasoline, due to the greatly reduced bum duration.

The goal of this investigation was to gain a better understanding of the effect of fuel/air charge composition on the dynamical structure of cyclic dispersion in lean-fueled spark ignition engines. Swirl and fuel injection timing were varied on a single-cylinder research engine to investigate the effects of charge motion and stratification on prior-cycle effects under lean operating conditions. Temporal patterns in the cycle-to-cycle combustion dynamics were analyzed using return maps, Shannon entropy, and symbol sequence statistics. Our results indicated a transition from stochastic behavior to noisy nonlinear determinism as equivalence ratio was decreased from near stoichiometric to very lean conditions. The equivalence ratio at which deterministic effects became important was strongly influenced by swirl and fuel injection timing. A comparison of our results and previous results from an eight-cylinder production engine showed similar trends.

Piston design that incorporates the heat pipe cooling technology may provide a new approach for piston-temperature control. A simulated piston crown that contains an annular reciprocating heat pipe is developed to investigate the effect of heat pipe cooling on the piston crown temperature distribution. For this purpose, a reciprocating engine testing apparatus is designed and constructed. The experimental study focuses on the static and dynamic operational characteristics of the heat pipe and its cooling effect on the simulated piston crown under different power input. The experiment results indicate that a piston crown incorporating a heat pipe can yield a uniform temperature distribution in the ring-bank area of the piston crown. The testing results would also provide the needed information for a possible piston design that incorporates the heat pipe cooling technology for improved thermal-tribological performance.

The first part of this series of papers reports the development of a simulated piston crown with an annular reciprocating heat pipe and the investigation on the effect of heat-pipe cooling on the piston-crown temperature distribution. This paper presents the modeling of the simulated piston crown with the finite-element method and the analysis of its thermal performance. The heat-transfer coefficient with respect to the reciprocal environment of the experimental apparatus and the effective thermal conductance of the annular heat pipe are determined by correlating the modeling with the experimental measurements. The numerical modeling agrees well with the experimental results. The analyses indicate that the heat-pipe cooling technology can provide an effective means for piston temperature control.

This work was carried out as part of the European project IDEA EFFECT. The aim of this research was application of a commercial computational fluid dynamic (CFD) package STAR-CD to real engine flow. The Volkswagen (VW) two-valve transparent 1.9 l direct injection (DI) diesel engine was used to simulate flow field in the inlet port and combustion chamber under engine speeds of 1000 rpm and 2000 rpm. The CFD predictions were verified by Laser-Doppler anemometer (LDA) measurements under motored condition during three periods: valve opening, valve closure and the maximum valve lift. This paper discusses the predicted flow structure and its main features under different engine speeds, and examines the validity and accuracy of the CFD predictions in comparison with measured data.

This paper describes the process of incorporation of 25% post-industrial recycled sheet molded composite (SMC) material in the 1998 Continental Hood inner. 1998 Continental Hood assembly consists of traditional SMC outer and this recycled hood inner along with three small steel reinforcements. BUDD Plastics collects SMC scraps from their manufacturing plants. The scrap is then processed and made into fillers for production of SMC. Strength of SMC comes from glass fibers and fillers are added to produce the final mix of raw materials. This recycled material is approximately 10% lighter and less stiff than the conventional virgin SMC. This presented unique challenges to the product development team to incorporate this material into a production vehicle in order to obtain the desired goal of reducing land fill and improving the environment.