Aerodynamic Drag Analysis of Autonomous Electric Vehicle Platoons

Sai Teja Kaluva,Aditya Pathak,Aybike Ongel

doi:10.3390/en13154028

Abstract

Vehicle platooning has been proposed as one of the potential technologies for intelligent transport systems to improve transportation and energy efficiency in urban cities. Despite extensive studies conducted on the platooning of heavy-duty trucks, literature on the analysis of urban vehicle platoons has been limited. To analyse the impact of platooning in urban environments, this paper studies the influence of intervehicle distance, platoon size and vehicle speed on the drag coefficient of the vehicles in a platoon using computational fluid dynamics (CFD). Two vehicle models—a minibus and a passenger car—are analysed to characterise the drag coefficients of the respective platoons. An analysis of energy consumption is conducted to evaluate the energy savings with platooning using a longitudinal dynamics simulation. The results showed a reduction in the average drag coefficient of the platoon of up to 24% at an intervehicle distance of 1 m depending on the number of vehicles in the platoon. With a larger intervehicle distance of 4 m, the reduction in the drag coefficient decreased to 4% of the drag coefficient of the isolated vehicle. Subsequently, energy savings with platooning were calculated to be up to 10% depending on the driving cycle, intervehicle distance and platoon size.

Highlights

Advances in intelligent transport systems along with the automation of the vehicles have enabled the development of vehicle platooning strategies in which a group of vehicles follow each other in a close and coordinated way [1], primarily to increase road capacity [2] and reduce overall energy consumption
In comparison to the vehicle in isolation, the results showed an increase in the drag coefficient of the lead vehicle and a reduction in the rear vehicle0 s drag coefficient for an intervehicle distance of less than one vehicle length (VL)
At intervehicle distances below 1 m, the drag coefficient of the front body reduced in comparison to the isolated value, while that of the rear body increased

Summary

Introduction

Advances in intelligent transport systems along with the automation of the vehicles have enabled the development of vehicle platooning strategies in which a group of vehicles follow each other in a close and coordinated way [1], primarily to increase road capacity [2] and reduce overall energy consumption. With improvements in sensor and communication technologies, vehicles can be electronically coupled and controlled to drive together at closer distances in a platoon, thereby reducing the energy consumption due to the aerodynamic advantage of driving in close proximity [3]. Aerodynamic drag is one of the major contributors to the energy consumption of a vehicle and increases quadratically with the increase in vehicle speed. The pressure drag, which is the major contributor to the overall drag, arises due to the pressure difference between the high pressure region at the front of the vehicle and the low pressure region at the rear of the vehicle. When a vehicle is driven in a platoon, the pressure difference on the vehicle is reduced. Platooning decreases the aerodynamic drag and improves the energy efficiency of the vehicle

Methods

Results

Conclusion