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Today most catalytic converter designs have monolith-type substrates. Many of these designs use more than one monolith, due to different catalyst loadings or constraints on the manufacturing or coating of long monoliths. There is usually an open space between the monoliths. The flow distribution in the catalytic converter depends on the cone geometry of the catalytic converter, the space between the monoliths and their design. A connection between the flow distribution and the high conversion rate and the good long term stability is supposed. This paper presents the results of a study of the influence of space between monoliths, cone geometry and monolith length, on flow distribution, catalytic converter conversion rate and backpressure. The conversion rates for HC, CO and NOx at different engine load levels have been investigated.

This paper describes the development of an improved catalytic converter for the Volvo 850, equipped with a turbo-charged engine which could meet future legislations such as LEV and ULEV. The target has been to develop an underfloor catalytic converter with an improved light-off, OBD2 robustness and less back pressure. The new converter technology, which incorporates substrates with increased cell density and decreased wall thickness shows improved characteristics with enhanced heat and mass transfer. An investigation of metallic substrates with different cell densities shows shortened light-off times with higher cell density. An oxygen storage investigation shows also that increased cell density is a very effective way to reduce the lambda perturbations after the catalyst, giving a stable rear oxygen sensor signal. In the present case this was desirable for the dual sensor system used together with a small catalyst volume in the first position of a cascade of several substrates.

As component sheet metals become thinner and surface properties prove to be more dynamic than ever, conventional induction heat catalyzed adhesives must evolve to perform under increasingly restrictive parameters. Thin metal distortion at typical induction cure temperatures, coupled with shelf life restrictions that seem to be inherent with most commercially available one component adhesive systems, has forced the need for a “Next Generation” hem adhesive. This presentation focuses on the recent development of a one component induction heat responsive structural adhesive which meets the critical requirements of the automobile manufacturing arena of the future. This adhesive system shows impressive results in low-temperature induction cure scenarios and has been capable of maintaining exceptional adhesion characteristics on numerous substrates.

The prediction of weld nugget diameter has been a primary objective in the development of resistance spot welding monitoring techniques. The prediction algorithms must be able to work with the wide range of process variations commonly encountered in a production environment. Welding experiments simulating process variations were conducted on AA5754 sheet with structural adhesive using AC welding equipment. The parameters and simulated production conditions were extremely wide ranging, and included welding sections of actual car components. Results from the work have demonstrated that by using suitable electrical signals sampled from the process, robust models can be designed that are capable of making good diameter predictions under a wide range of welding conditions.

Previous work has shown that variations in wheel alloy chemistry, particularly with respect to copper and iron levels, can have a pronounced effect on filiform corrosion performance. In this study, an examination of A356.2 alloy chemistry variants and their effects on corrosion was carried out in greater detail. The emphasis was on copper and iron variants, both alone and in combination. Copper levels ranged from 0.005 to 0.22% and iron from 0.04 to 0.23%. The effect of manganese additions was also examined, with levels ranging from 0.002 to 0.07%. In addition to the alloying variants, the level of dispersed oxides in the castings was varied to determine any effects on corrosion performance. Although filiform corrosion performance of painted samples was the primary focus of this study, the corrosion behaviour of unpainted samples was also evaluated for comparison purposes.

An extensive field study was made of the corrosion of aluminum alloy panels in over fifteen years of service in three regions of the USA. Panels removed from service exposed vehicles were subjected to further testing to determine the relationship between field service, accelerated laboratory corrosion testing, and marine environment exposure for two years at Daytona Beach, Florida. In addition, two 42 year old aluminum bodied Dyna Panhard vehicles were recovered in France, examined closely, and subjected to similar tests. Few examples of significant corrosion were found in the field, and only one example of filiform corrosion on aluminum sheet in service. Steel panels on the same vehicles frequently rusted through, and filiform corrosion was seen occasionally. Laboratory tested aluminum panel samples frequently showed filiform corrosion and severe intergranular corrosion.

Hyrdroformed tubes have seen use in the aerospace industry for many years and are seeing increased use in the automotive body-in-white (BIW). The automotive industry has chosen to use hydroformings for a number of reasons including reduced part weight, piece count reduction, and the flexibility to form complex shapes of varying wall thickness. With all of these potential advantages, still one more provides the greatest incentive to switch from a stamped assembly to a hydroformed tube: the ability to reduce cost. It is generally accepted that hydroformings can indeed be cost effective to produce, yet the question remains: when should a stamped assembly be replaced by a hydroformed component? This paper will attempt to answer the question above by laying out several case studies and comparing their direct manufacturing costs.

Tubular hydroforming processes provide a number of advantages over conventional stamping processes including reduction in the number of parts, and reduction in the tooling and material costs. As a result, the technology has drawn increasing attention in the automotive industry. However, there is still little experience available of both the forming process and its FEM simulation. The current experimental and FEM simulation study has been initiated to gain a better understanding of the fundamentals of hydroforming processes. This paper summarizes experimental and analytical results of a hydroforming process which expands a circular tube into a rectangular cross-section. A better understanding is obtained of the relationship between internal pressure and axial displacements, mechanisms of buckling, splitting and corner fill-ins. Splitting, buckling and the tubular hydroforming zones are identified on the traditional Forming Limit Diagram.

The rapidly developing hydroforming industry has become almost a mainstream technology for the manufacture of automotive structural components. Technical information and claims are often incomplete, unspecific and unsupported by production experience and data. This paper contains data accumulated from a hydroforming process that has been in high volume production for 8 years. An objective presentation, explanation and discussion of this information gives a unique view of what is being done at present. It should act as an authoritative reference point against which dimensional capability claims can be judged.

The 1999 Oldsmobile Alero incorporates an instrument panel utilizing several advanced manufacturing technologies. The instrument panel, molded from a glass-filled Styrene-Maleic Anhydride (SMA) resin, uses the gas-assist process to produce a gas channel of approximately nine feet in length (see figure 1). This process includes multiple gas injection locations, a heated manifold system with (9) sequentially gated injection locations and a delayed gas blowback technique.

Using modified versions of the KIVA-II and KIVA-3 CFD codes, intake, compression, and combustion of a Caterpillar diesel engine was modeled. Seven variations on intake and two injection schemes were explored so that a detailed understanding of the effects of intake on various flow properties and their subsequent influence on combustion and emissions could be obtained. The results revealed that, in many cases, one of three factors: swirl ratio, temperature, and turbulence, was dominant in describing a combustion or emission behavior. In addition, stratification of fuel and oxygen was found to be a result of high swirl ratios. This had a profound impact on combustion and emissions, especially for split injection cases.

The experiments were performed with two types of test engines, '72 model year type and '94 model year type engine, using both of conventional diesel fuel and synthetic diesel fuel, which has simple hydrocarbon components and no aromatics or sulfur content. SOF is extracted from the particulate sample exhausted out from the engines, then GC and GC-MS analyses were carried out. By comparing the results obtained, the role of high boiling point components in diesel fuel on SOF emission were observed. Further, by adding an artificially sulfur-containing compound and pyrene, which is a four ring polynuclear-aromatic-hydrocarbon (PAH), into the synthetic fuel, the effect of PAH content in fuel on PAH emission in SOF and the increase of SOF with increased sulfur content in fuel, were observed.

Measurements of the temporal evolution of the 3-D velocity field were performed in an IC engine during the latter part of the intake stroke using a Water Analog Engine Simulation Rig and the 3-D Particle Tracking Velocimetry technique (3-D PTV). The engine head tested was a typical 4 valve, pent-roof type combustion chamber shape with slightly asymmetric intake passages to favor a preferred swirl with one intake valve almost deactivated to reinforce the swirling flow pattern. This study was aimed at characterizing the dynamic development of the flow field resulting from this head geometry and asymmetric valve event during the latter part of the intake stroke. The most salient feature of this flow field is that this final, highly organized and energetic vortex does not emerge until relatively late in the intake stroke. Even as late at 60° BBDC, the flow field is still characterized by smaller (of the order of 1/4 or 1/3 of the bore size) structures, particularly in the tumble plane.

We present a life cycle assessment of producing automobiles using the Environmental-Input-Output analysis tool (EIO-LCA). The tool is based on the 1987 U.S. 519 sector input-output table. Appended to the table are more recent data on energy usage and environmental discharges for each sector. All of the data, from the input-output matrix to the energy use and environmental discharges are U.S. government data and are publicly available. The EIO-LCA tool allows us to estimate all of the energy use and environmental discharges associated with making cars, not just that associated with automobile manufacturers. In contrast to the SETAC-EPA life cycle analysis tool, there is no need to draw an arbitrary boundary for the analysis or to engage in an expensive, time consuming effort to gather data on energy use and environmental discharges from each plant. In addition, the data are not confidential.

A set of experiments has been performed which were aimed at quantifying the effects of specific intake port geometry changes on large-scale in-cylinder motions. Using a modular engine with replaceable intake port blocks, 3 different intake ports were used and results obtained at 3 crank angles: BDC, 90° before TDC of compression, and at TDC of compression. For each port, in-cylinder flows were quantified using a pulsed laser and high-speed imager. The resulting images were analyzed using a particle-tracking scheme. The results of the experiments indicate that there are significant differences among the flows produced by the ports, particularly at BDC. Nearer TDC, the differences among the flows diminish, but some differences in velocity and vorticity scale and distribution remain. Tumble ratios are shown, using a variety of tumble ratio calculation methods.

The international standardisation of Environmental Management (EM) is documented by the ISO 14000 series. Within this series a number of Environmental Management tools are treated. Therefore, it can be seen as a ‘toolbox’ which offers several options for sound Environmental Management practices in organisations. However, a number of questions remain because they are not treated by the standards themselves. Some examples are, which of the tools should be applied to what kind of Environmental Management problem or what are the synergisms and antagonisms between these tools. To illustrate the importance of a comprehensive choice and a compatible approach towards EM-tools, Life-Cycle-Assessment (ISO 14040 series) is discussed in the context of Environmental Management Systems (ISO 14001). The focus of ISO 14001 are organisations, while LCA deals with products or processes.

In 1989, Volvo pledged to minimize the environmental effects of its operations by adopting a holistic approach to the environmental impact of its products, at every stage of their life cycle. As a means to achieve this goal, it was decided to use Life-cycle Assessment (LCA) philosophy. In collaboration with the Swedish Environmental Institute (IVL) and the Federation of Swedish Industries, an evaluation system based on the environmental goals adopted by the UN Conference on Environment & Development (UNCED), held in Rio de Janeiro in 1992, has been developed. Based on this evaluation method, a computerized tool known as EPS - Environmental Priority Strategies in product design - was born. It is made for use by non-LCA practitioners such as design engineers and purchasing staff. This software, particularly well adapted to the profile of Volvo's products, was introduced in the company in the beginning of the nineties.

Urethane is utilized to bond the windshield and backlite to the vehicle frame. The contribution of different modulii of glass bonding urethane adhesives on the stiffness characteristics of the vehicle is studied through finite element analysis. The modal analyses of a finite element body-in-white model with different modulii of urethanes are performed, and the analyses show that high modulus urethane makes notable contribution to the vehicle stiffness. The optimized modulus of urethane adhesive is suggested based on the analyses.

Perforated ducts are present in most designs of exhaust mufflers, due to their convenient sound attenuation properties. While suitable tools are available for the estimation of this attenuation, accounting for the influence on attenuation of the perforated ducts for different arrangements, a similar tool but related to the back-pressure generated by mufflers containing perforated ducts is not available. In this paper, the basis for such a tool are set by defining a suitable characterisation of perforated pipes that may allow for the consideration of the influence of a particular perforated duct on the back pressure generated by a given muffler. The results obtained have been validated in a particularly simple case, and the results confirm the feasibility of the proposed methodology, while suggesting possible future improvements.

In order to improve corrosion resistance and thermal efficiency of the air conditioner evaporator, a coating which provides hydrophilicity was formed over the chromate coating. In addition, there has been greater demand for air with fewer smells. This report describes the cause of “dusty odor” and a method to reduce it. The dusty odor is caused by a little corrosion of the substrate aluminum. Hydrophilic coating film dissolves little by little in condensed water, and substrate aluminum is exposed. A method to prevent the odor was developed by forming a coating giving hydrophilicity and durability to the evaporator surface.