Hyundai Motor Company and Kia Corporation have unveiled the ‘Active Air Skirt’ (AAS) technology, which they say 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 an electrified 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 power 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.
How does AAS work?
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 80kmph when the aerodynamic resistance becomes greater than the rolling resistance and is stored again at 70kmph. The reason for the difference in deployment and storage speeds is to prevent frequent operation in specific speed ranges.
Also, 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 for EVs. This is because it is more effective in improving aerodynamic performance to only cover the tire part since the platform floor is flat. This also functions to enhance downforce of the vehicle, thereby improving vehicle traction and high-speed stability.
The partners say AAS can even operate at speeds over 200kmph. This is 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.
Hyundai Motor and Kia announced that they have tested and reduced the drag coefficient (Cd) by 0.008, improving drag by 2.8 percent, by installing AAS in Genesis GV60. This is a figure that can expect an additional range improvement of about 6km.
The partners have applied for related patents in South Korea and the United States, and plan to consider mass production after durability and performance tests.
Sun Hyung Cho, VP and Head of Mobility Body Development Group at Hyundai Motor Group said, “This technology is expected to have a greater effect on models such as SUVs where it is difficult to improve aerodynamic performance. We will continue to strive to improve the driving performance and stability of electric vehicles through improvements in aerodynamics.”
Meanwhile, Hyundai Motor and Kia are applying various technologies, such as rear spoilers, active air flaps, wheel air curtains, wheel gap reducers and separation traps, to vehicles to secure competitive drag coefficients. Hyundai IONIQ 6, which incorporates these technologies, has achieved a global leading Cd of 0.21.
