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We used a one-dimensional monolithic catalyst model to predict the transient thermal and conversion characteristics of a dual monolithic catalytic converter with a Palladium only (Pd-only) catalyst and a Palladium/Rhodium (Pd/Rh) catalyst. Prior to the numerical investigation of the dual-catalyst converter, we modified the pre-exponential factor and activation energy of each reaction for both catalysts to achieve acceptable agreement with experimental data under typical operating conditions of automobile applications. We validated the conversion behavior of the lumped parameter model for each catalyst against different engine operating conditions. Two higher cell density substrates, Pd-only catalyst (600cpsi/3.9mil) and Pd/Rh catalyst (600cpsi/4mil), for faster light-off and improved warm-up performance are used in this study and the two monoliths has been connected without the space between monoliths.

An on-board monitoring system for an automobile emission gas has developed using porous ceramic sensor to apply in automotive. We have performed model experiment using similarity and engine dynamometer experiment. By the model experiment, output signal of HC sensor is followed with amount of hydrocarbon in the mixed gas under high temperature range. A single hydrocarbon sensor exposed to the exhaust gas in the chamber to render a signal responsive to the hydrocarbon. The HC sensor in test chamber checked the conductive ions in emission gas. A preferred application includes hydrocarbons in an automotive exhaust gas stream by exposing a porous alumina (Al2O3) ceramic based sensor to the same exhaust gas stream. By combining the electrical signal, a measure of hydrocarbons can be provided. By the developed temperature mode test and the load mode test for engine dynamometer experiment, we have confirmed a possibility of catalyst monitoring used HC sensor in the engine dynamometer.

Main role of fuel rail for GDI (Gasoline Direct Injection) system is to store and distribute gasoline between high pressure pump and injector. Under the engine operating condition, fuel pressure and ambient temperature are applied to fuel rail as fatigue load, which can cause fatigue failure. To meet current a global environmental regulation, a fuel injection pressure is gradually increasing. Therefore a fuel rail for GDI engine which is installed between fuel pump and injector must be stronger than now. Also the target reliability of the fuel rail has to be increased than before. Accordingly, fatigue behaviors of fuel rail must be analyzed and expected at the development stage. In this study, a procedure for assessment the fatigue life of GDI fuel rail was developed. With this, fatigue load on the GDI fuel rail can be expected under actual vehicle operating conditions. Furthermore, fatigue life of a part can be verified based on the expected fatigue load.

A thermal fluid flow analysis for multiflow channel(MFC) condenser for automotive air-conditioning system using HFC-134a refrigerant has been carried out. The present study has been done as a part of the work intended to develop a design tool of HFC-134a refrigerant air conditioning system for passenger vehicle by applying a steady state simulation scheme to obtain the performance optimization. Thermodynamic and flow properties of HFC-134a refrigerant and temperature profile of the air flow over the surface of MFC condenser are predicted as a function of flow channel distance using a model of finite difference method. Variations of the heat transfer rate and pressure distribution are predicted under consideration of the actual multiflow channel constructions. The results of the predicted analysis obtained from the simulation analytical model were found to be conform with the known actual operation conditions of HFC-134a condenser in passenger vehicle air conditioning system.