Hyundai Motor Company and Kia Corporation today unveiled the ‘Active Air Skirt’ (AAS) technology that minimises the aerodynamic resistance generated during high-speed driving, effectively improving the driving range and driving stability of electric vehicles (EVs).
AAS is a technology that controls the flow of air entering through the lower part of the bumper and effectively controls the turbulence generated around the vehicle wheels by operating variably according to the vehicle speed during high-speed driving.
In the EV era, competition to secure a better driving range from a single charge has become fierce, making the relationship between vehicles and aerodynamics even more important. Furthermore, aerodynamic performance has a significant impact not only on performance, but also on driving stability and wind noise.
In response, manufacturers are exploring various measures to reduce the coefficient of drag (Cd), which is the resistance coefficient of the air acting in the opposite direction of the vehicle’s motion.
AAS is installed between the front bumper and the front wheels of the vehicle and is hidden during normal operation, but it operates at speeds over 80km/h when the aerodynamic resistance becomes greater than the rolling resistance. The system is stored again when the vehicle slows down below 70km/h. The reason for the difference in deployment and storage speeds is to prevent frequent operation in specific speed ranges.
The reason why AAS only covers the front part of the tyres without completely covering the front is related to the characteristics of Hyundai Motor Group’s e-GMP platform. This is because it is more effective in improving aerodynamic performance to only cover the tyre part since the platform floor is flat. This also functions to enhance downforce of the vehicle, thereby improving vehicle traction and high-speed stability.
AAS can also operate at speeds over 200km/h. This was possible thanks to the application of rubber material on the lower part, which reduces the risk of external objects splashing and damaging while driving at high speeds and ensures durability.