The first part of this thesis involves full experimental and numerical studies to understand the effects of cross-winds on the automotive underbody aero-thermal phenomena using a 2005 Chevrolet Aveo5 with a heat source affixed to it to create a baseline. The results show that irrespective of the yaw angle used, only temperatures in the vicinity of the heat source increased. The rear suspension also deflected the airflow preventing heat transfer. The second part of this thesis investigated using a diffuser to improve hybrid electric battery pack cooling. It was found that the diffuser led to more consistent temperatures on the diffuser surface, suggesting the same for the battery.
