Hyundai and Kia have unveiled ‘Active Air Skirt’ (AAS), a technology designed to minimise the aerodynamic resistance generated during high-speed driving, effectively improving the driving range and driving stability of electric vehicles (EVs).
The AAS is installed between the lower part of the front bumper (fender) and the front wheels of the vehicle and is hidden during normal operation. When the vehicle reaches speeds over 80km/h – a speed at which the aerodynamic resistance becomes greater than the rolling resistance – the air skirt deploys and controls the turbulence generated around the vehicle wheels to enhance aerodynamic performance and yield benefits in terms of driving stability, range efficiency, and wind noise. The skirt retreats back into the bumper area again at 70km/h in order to prevent frequent operation in specific speed ranges.
The AAS can also operate at speeds over 200km/h thanks to the rubber material on the lower part, which reduces the risk of external objects splashing and damaging the mechanism while driving at high speeds.
The engineering team determined that the AAS should only cover the front part of the tyres rather than the whole front of the vehicle due to the characteristics of Hyundai Motor Group’s E-GMP platform for EVs. The team found that only covering the tyres is more effective in improving aerodynamic performance because the floor of the vehicle platform is flat. The design also enhances the downforce on the vehicle, thereby improving vehicle traction and high-speed stability.
Hyundai Motor and Kia claim that during testing of AAS on a Genesis GV60 EV, they found that AAS reduced the drag coefficient (Cd) by 0.008, an equivalent of 2.8%. They estimate that this a figure that can yield a range improvement of about 6km.
Hyundai Motor and Kia have applied for related patents for AAS in South Korea and the United States, and will consider mass production after further durability and performance tests.
“This technology is expected to have a greater effect on models such as SUVs where it is difficult to improve aerodynamic performance,” said Sun Hyung Cho, Vice President and Head of Mobility Body Development Group at Hyundai Motor Group. “We will continue to strive to improve the driving performance and stability of electric vehicles through improvements in aerodynamics.”
In related news, Hyundai Motor and Kia are applying various technologies to vehicles in order to improve drag coefficients, such as rear spoilers, active air flaps, wheel air curtains, wheel gap reducers and separation traps. The Hyundai IONIQ 6, which incorporates these technologies, has achieved a Cd of 0.21.