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Thermal effects on three-way catalysts and deterioration characteristics were studied. Aging atmosphere (oxidizing or reducing) and temperature contributed to catalyst performance deterioration. Catalysts sharply lost their activities under oxidizing conditions at an aging temperature of 900°C and above. Thermal degradation was found due mainly to the decrease in the surface area of alumina coated on the substrate and the increase in the size of cerium oxide (CeO2) crystal particle, an oxgen storage component (OSC). Also observed was a close correlation between the alumina surface area loss and the volume loss of micro pores with their radius less than 100 Å. Tests demonstrated that the catalyst thermal degradation can be reduced if the alumina micro pore volume loss and the CeO2 crystal particle size increase are restrained.

Seat lumbar support is thought to be essential for seating comfort as it plays important role in the driver's fatigue during long term driving. We tried to evaluate the lumbar support performance objectively with Seat Pressure Distribution. First, the tolerance in the measurement was eliminated by application of ASPECT manikin that reproduced a human seating torso posture [1, 2]. Second, an analysis method to visualize the seat support balance on the human back was developed. Third, a hypothesis for the optimal support balance to minimize the fatigue was proposed according to the fatigue growing mechanisms. Examining the deviation of each seat result from the optimal support, the performances were quantitatively evaluated. In addition to that, the effect of the lumbar support adjuster was taken into consideration to predict the market evaluation more precisely.

The International Lubricant Standardization and Approval Committee (ILSAC) ATF subcommittee members have compared the two oxidation bench test methods, Aluminum Beaker Oxidation Test (ABOT) and Indiana Stirring Oxidation Stability Test (ISOT), using a number of factory-fill and service-fill ATFs obtained in Japan and in the US. In many cases, the ATFs were more severely oxidized after the ABOT procedure than after the same duration of the ISOT procedure. The relative severity of these two tests was influenced by the composition of the ATFs. The bench test oxidation data were compared with the transmission and the vehicle oxidation test data.

Aerodynamic noise generated in production vehicle has been evaluated using experiment and numerical simulation. Finite difference method (FDM) and finite element method (FEM) are applied to analyze the flow field, and Lighthill's analogy is employed to conduct acoustic analysis. The flow fields around front-pillar obtained by numerical simulations agree with those by experiment for two cases with different front-pillar shape. Moreover, the distribution of acoustic source predicted by FEM is consistent with that obtained by experiment. Present study ascertained the feasibility and applicability of FEM with SGS model towards prediction of aerodynamic noise generated in production vehicle.

The thermal efficiency of a three-rotor rotary engine (RE) was improved by a reduction in the pumping losses. These pumping losses were reduced by using a new port mechanism. The port mechanism utilized was an indirect recirculation type of late intake port closing. It was equipped with a recirculation chamber outside of the housings. This chamber interconnected the recirculation ports within each housing. This port mechanism yielded three main benefits 1. A Considerable reduction in the pumping losses. 2. A uniformly distributed air-fuel mixture in each housing. 3. A limited amount of residual gas in the housing. This residual gas was under specific pulsations by the recirculation chamber thus preventing deterioration in combustion under light loads. The above phenomena were clarified by experiments and simulations. The possibility of a reduction in exhaust emissions was also investigated.

New press forming method was developed for ensuring shape-accuracy of draw parts with high strength steel sheet(HSS) of very high tensile strength such as 780MPa. In the new method, step drawing method was combined with crash forming method by applying cam flange die structure to drawing dies. Furthermore, the die structure in the method is simple. At the trial press-forming by the model die even with 780MPa high strength steel sheets, the side wall warps in particular were restrained within a specified tolerance, that is ±0.00067[1/mm] of the variation of curvature(Δ 1/ ρ). Now the method is applied to press-forming some automotive body parts, such as front side member, etc.

Control of self-ignition timing in a HCCI engine is still a major technical issue. Recently, the application of a non-equilibrium plasma using repetitively discharge has been proposed as the promising technology. However, non-equilibrium plasma reaction in higher hydrocarbon fuel mixture is very complicated. Hence, there have been few calculation reports considering a series of reactions from non-equilibrium plasma production to high temperature oxidation process. In this study, 0-dimensional numerical simulation model was developed in which both reactions of plasma chemistry and high temperature oxidation combustion was taken into account simultaneously. In addition, an ODEs solver has been applied for the reduction of calculation time in the simulation. By comparing calculation results with experiment such as self-ignition timing, the validity of the developed numerical model has been evaluated.

The growing competition of the automotive market makes more and more necessary the reduction of development time and consequently, the increase of the capacity to quickly respond to the launching of the competitors. One of the most costly phases on the vehicle development process is the field durability test, both in function of the number of prototypes employed and the time needed to its execution. More and more diffused, the fatigue life prediction methods have played an important part in the durability analysis via CAE. Nevertheless, in order they can be reliable and really being able to reduce the development time and cost, they need to be provided with load cases that can accurately represent the field durability tests. This work presents a CAE approach used for light trucks in order to get a reasonable understanding of component durability behavior due to payload increase. In general, road load data is not available for a new payload condition.