Model Development, Simulation and Validation, of Power Train Cooling System for a Truck Application

Power train cooling control is becoming a topic of increasing interest as evidenced by the recent surge of activities that suppliers of automotive power train cooling and HVAC systems are reporting in literature. The goals of these activities are to achieve better fuel economy, lower emissions and increased passenger comfort by controlling coolant flow through the different system components. In order to study any of the ideas in this area, a simulation model must be developed to sift through them for the most practical and effective method to avoid the high cost of hardware builds and long testing hours. This work uses the EASY5 simulation package (a product of the Boeing Company) to model such systems. A model is developed for a pick up truck application and is validated against test results. At this stage, the model has only the basic components namely the radiator, the water pump, a surge (return) tank, hoses and pipes, and the engine thermal load. Although the model lacks detailed representations of the engine thermal model, the oil circuit, the air dynamics, and the thermostat behavior, simulation results show good agreement with test results and their trends. The model is being expanded to include engine thermal model as well as additional elements such as a thermostat model (both passive and electronically controlled), air dynamics and HVAC/heater details. Electronic controls will be integrated with the model in the near future to study different strategies for fuel economy and emissions improvement.