Multi-objective optimization study on the power cooling performance and the cooling drag of a full-scale vehicle.

Obtaining an excellent power cooling performance of the engine and minimizing the cooling drag in the underhood compartment are vital for safe driving and energy saving of vehicles. For this purpose, a multi-software co-simulation platform including the mesh deformation (Sculptor), computational fluid dynamics (Star-CCM+), and thermal management (KULI) software, was established by script compilation in the ISIGHT software. Based on this platform, a multi-objective optimization design method was proposed to study the outlet water temperature of the engine (OWTE), the inlet air temperature of the engine (IATE) and the cooling drag coefficient (CDC) of a typical multi-purpose vehicle (MPV) by combining the second-order response surface method (RSM) and the Non-dominated Sorting Genetic Algorithm II (NSGA-II). The results of sensitivities showed that the design variable V11 representing the fan speed had the most significant effect on the OWTE, IATE, and CDC. Through the grey relational analysis method, the trade-off optimum point was obtained. It was in good agreement with the result derived from the CFD simulation, with the maximum relative error less than 1.4%. Compared to the baseline values, the optimized CDC decreased by 21.0% and the power cooling performance of the engine was well guaranteed. It indicated that the proposed multi-objective optimization design method based on the co-simulation platform, owed the ability to solve the problem of compromising the design of power cooling performance and cooling drag in the underhood compartment of typical MPVs. [ABSTRACT FROM AUTHOR]