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This paper describes theoretical model developed for analyzing the heat transfer of automotive cooling systems. The model has a modular structure which links various cooling system submodels. From the model, heat transfer rate of automotive cooling systems can be predicted, providing useful information at the early stages of the design and development. The aim of the study is to develop a simulation program for automotive cooling system analysis and a performance analysis program for analyzing heat exchanger. Heat release rate from combustion gas to coolant through cylinder wall in engine cylinder was analyzed by using engine cycle simulation program. In this paper, details of each submodel are described together with the overall structure of the vehicle model.

To reduce air pollution by the exhaust gases from automotives, it is necessary to control air/fuel ratio appropriate to engine operating condition, which can be achieved by adopting an electronic control system. In this study we designed and fabracated PC-ECU (Personal Computer interfaced - Electronic Control Unit) to develop the automotive engine control system. PC-ECU is made to perform engine control with the application of various control logics instead of the C-ECU. As a first step to develop control logics we applied jump-ramp control to the real engine using a simple on/off O2 sensor and performed engine control by the use of PC-ECU. Also, we introduced a wide band O2 sensor instead of the simple on/off O2 sensor and adopted the PI control. The results show that the control performance in case of using a wide band O2 sensor is much better than in case of using a simple on/off O2 sensor.

In order to suggest an efficient catalyst system for automotive emission control, Pd-WO3 and Pd-La2O3 catalysts were characterized before and after simulated thermal aging and phosphorous contact. From the results of H2 chemisorption experiment, it was found that the particle size of Pd was decreased and the dispersion of metal was increased by the promotion of La2O3, which results in the enhancement of thermal durability. Also it was found that deactivation of Pd-WO3 involves severe metal vaporization during thermal aging. By engine exhaust gas test, it was observed that Pd-La2O3 catalyst was sensitive against phosphorous poisoning up to certain value of phosphorous accumulation while it has exceptional thermal stability.