Abstract: The front-end intake air volume of vehicle cooling system directly affects the heat dissipation performance and aerodynamic resistance of engine compartment. In view of the overcool and overheat of engine under the high-speed and lower-speed conditions of the passenger car with active grille shutter (AGS), computational fluid dynamics (CFD) technique is adopted to analyze the effects of AGS angle and fan speed on the flow field of engine compartment. The optimization matching criteria and scheme of grille angle and fan speed are established and the real effects of matching scheme are verified by the simulation on a real example. The results show that the matching scheme of air intake module proposed can meet the requirements of heat dissipation under extreme conditions with a fuel consumption reduced by 0.166 L/100km.

Key words: engine compartment, heat dissipation, aerodynamic resistance, grille angle, cooling fan, optimal matching