Full vehicle CFD investigations on the influence of front-end configuration on radiator performance and cooling drag

摘要

Proper underhood airflow management of road vehicles has two distinct objectives, viz, ensure the required cooling performance of the heat exchangers, and minimize the cooling drag component of the total vehicle drag. From the radiator performance perspective, there are distinct concerns according to the vehicle speeds. At highway speeds, the flow rate and flow-distributions over the radiator surface are the major operating parameters influencing the performance of a radiator. However, at low vehicle speeds, a phenomenon detrimental to the A/C system performance, called the underhood hot air recirculation, may occur. The cooling airflow not only causes drag directly, the interaction of under-body flow with other vehicle components may lead to more interference drag. This paper presents computational studies to investigate underhood airflow features associated with radiator performance and cooling drag. Additionally, analysis of the impact of the front grille opening size and underhood passive aerodynamic devices on the cooling drag and radiator performance are presented based on full vehicle CFD simulations carried out using a model of Hyundai Veloster. It is demonstrated in this study that by properly manipulating the cooling airflow pattern, simultaneous improvement of radiator performance and total vehicle drag can be achieved. (C) 2017 Elsevier Ltd. All rights reserved.