Numerical Investigation of the Air Flow in a Simplified Underhood Environment

Thermal management plays a crucial role for the energy efficiency of electrified vehicles. Using numerical flow simulations, the air paths and temperature distributions in the underhood can be identified and optimised early in the development process. However, the numerical method needs to be verified in its accuracy for capturing the important flow features in the underhood. In this study, a numerical approach is developed that is robust with respect to spatial and temporal resolutions as well as to different turbulence models. The methodology is validated against experimental data from LDA measurements. The geometric configurations investigated are representative of electrified vehicles, with one or two front opening designs, two different fans, and with or without a blockage behind. The results showed that for one of the fan installations, although the major flow field structures were well captured, the locations of the peak velocities did not match the experiments. For the second fan, the CFD results agreed well with the measurements.