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The Low Temperature Cooling (LTC) system is commonly developed for secondary cooling function requirements, such as forced induction air cooling, and HEV power electronics module cooling. The large heat transfer capacity of coolant allows for very compact water-cooled heat exchangers to be installed remotely for better underhood aerodynamic characteristics and more compact packaging design. An integrated LTC loop developed on a Hyundai 2.0L Turbo Charged vehicle extends a traditional WCAC (Water-cooled charged air cooler) application to include a water-cooled condenser (WCOND) module. Unlike other published LTC system design approaches, this research project emphasizes underhood airflow improvement strategy and focuses on heat transfer efficiency. This paper discusses the integrated LTC loop configuration, Low Temperature Radiator (LTR) design, coolant flow control, and others.

A numerical study is conducted to investigate the effect of changing engine oil and automatic transmission fluid (ATF) temperatures on the fuel economy during warm-up period. The study also evaluates several fuel economy improving devices that reduce the warm-up period by utilizing recycled exhaust heat or an electric heater. A computer simulation model has been developed using a multi-domain 1-D commercial software and calibrated using test data from a passenger vehicle equipped with a 2.4 / 4-cylinder engine and a 6-speed automatic transmission. The model consists of sub-models for driver, vehicle, engine, automatic transmission, cooling system, engine oil circuit, ATF circuit, and electrical system. The model has demonstrated sufficient sensitivity to the changing engine oil and ATF temperatures during the cold start portion of the Federal Test Procedure (FTP) driving cycle that is used for the fuel economy evaluation.

An assessment of stamped part quality and launch readiness occurs at many intervals. This paper will focus on dimensional control activities that take place after Stamping Dies are constructed, but prior to producing the stamped parts. Die certification and die repeatability measurements have been performed at DaimlerChrysler and the results are documented. This die certification process provides an opportunity to uncover and resolve die machining issues with respect to the part math model or pre-engineered compensation model prior to producing parts. Additionally, the die repeatability process is performed to determine the ability of the die gaging to locate the incoming in-process material consistently. This paper will explain the die certification and die repeatability processes and share what we have learned. It will describe the processes, the tools, the participants, the sites, the benefits, and the measurement equipment.