A Numerical Simulation Tool for Automotive Cooling System Design

Aim of this paper is to present a simulation tool for the design of engine cooling systems. In this mathematical model both the fluid streams are numerically solved. The model of the coolant flow outlines a computational inexpensive technique based on the one-dimensional network flow theory to analyze cooling circuits of high complexity. This tool involves the prediction of the coolant flow rates and temperature values for each component of the cooling system. Furthermore, a distributed parameter model is implemented in order to couple a Computational Fluid Dynamics (CFD) analysis concerning the air flow through the radiator and its affect on the heat transfer. The validation process of the distributed parameter model has been applied to a radiator test bench circuit. By using different heat exchange coefficient definitions the deviation between the experimental values and the computed ones has been pointed out. Moreover, a sensibility analysis to the grid resolution of the radiator numerical model has been carried out. Furthermore, a thermal management simulation based on the Maserati Quattroporte cooling system has been performed in order to verify the numerical prediction in a complex circuit, adopting also a non uniform velocity distribution through the radiator. These results have been compared with vehicle experimental data extrapolated from an environmental wind tunnel test, showing a good agreement with the reference data.