Hyundai has already installed active flaps on the front bumpers of the electric GMP models “Ioniq 5” and “Ioniq 6”, but these are purely responsible for opening and closing the radiator intake. This is also done for aerodynamic reasons (closing the flaps improves airflow), but the Koreans take it a step further with an “active air skirt.”
According to Hyundai, the AAS system is installed between the vehicle’s front bumper and front wheels and controls the flow of air that enters from the bottom of the bumper at speeds above 80 km/h. This controls the turbulence that occurs around the vehicle’s wheels. As a result, Hyundai and Kia hope to minimize the coefficient of drag (Cd) to improve the range and driving stability of electric vehicles.
During development test drives, engineers demonstrated effectiveness and accurately quantified improvements. The cruising range is expected to be improved by about 6 kilometers. It also increases downforce, improving the vehicle’s traction and stability at high speeds.
However, AAS is only active at high speeds. As mentioned earlier, it activates at speeds above 80 km/h and even at speeds above 200 km/h. When the car’s speed drops below 70 km/h, the expandable spoiler lip retracts again. The two air flaps are mounted in front of the front tires and do not span the entire width of the car. According to Hyundai, “Due to the flat floor of the platform, it is better aerodynamically to cover only the tire area.”
The system is an addition to the “air curtain” found in many EVs, which directs air past the front wheels through a small opening in the front to control turbulence. However, this only occurs at the height of the bumper, where the opening is recessed. The AAS is located in the underbody, which improves turbulence control in this area. However, his AAS with active elements is much more complex than a purely passive “air curtain”.
“This technology can be expected to have a greater effect on models such as SUVs, where it is difficult to improve aerodynamic performance,” said Sung Hyun Cho, vice president and head of the Mobility Body Development Group at Hyundai Motor Group. “We will continue to strive to improve the driving performance and stability of electric vehicles by improving aerodynamics.”
hyundai.com