Effects of separation distance, lateral offset, and yaw on the drag of a truck and SUV platoon

Abstract

The recent popularity of electric vehicles and upcoming governmental regulations on emissions are forcing automotive manufacturers to build more efficient vehicles. An approach to improve the efficiency of a road vehicle is by reducing its aerodynamic resistance. One way of achieving this is through platooning, vehicles drive in close-proximity. Despite of the extensive literature available on platooning of multiple vehicle types, most studies have focused on the drag and flow effects around the truck only. This work aims to increase the understanding and recognize the usefulness of a truck-SUV platoon system as a whole using wind tunnel measurements on two scale models and CFD simulations. From the results of this study, it was found that the effects on the SUV are large and contribute to a significant portion of the drag reduction of the system, especially at short inter-vehicle distances where the drag of the car can become negative. The drag reduction for the truck is generally limited as the truck is a much larger vehicle. For the system, the results show that for very short distances it is beneficial for the truck to lead the platoon, while at longer separations there is no preferable order.