Record-breaking aerodynamics
Audi A6 Sportback e-tron performance: Combined electric power consumption in kWh/100 km (62.1 mi): 15.9-14.0; combined CO2 emissions in g/km (g/mi): 0 (0) CO2-class: A
Audi A6 Sportback e-tron performance: Combined electric power consumption in kWh/100 km (62.1 mi): 15.9-14.0; combined CO2 emissions in g/km (g/mi): 0 (0) CO2-class: A
With an exceptionally low Cd value of 0.21, the Audi A6 Sportback e-tron1 achieves the best value an Audi production vehicle has ever registered. How has this been accomplished? Moni Islam, Head of Aerodynamics/Aeroacoustics Development, provides answers in the Audi wind tunnel.
The tube, where wind speeds up to 300 km/h are possible, is 47 meters long. The wind tunnel at Audi in Ingolstadt has an enormous capacity, while the operating noise is extremely low. "When the tunnel is empty, and we ramp up the wind, you can't hear anything," says Moni Islam, Head of Aerodynamics/Aeroacoustics Development at Audi, and explains: "The tunnel has to be this quiet that we can hear the wind noise on the vehicle. This is the only way we can reduce it to a minimum." Islam should know. The wind tunnel is like a second living room for him. To develop the aerodynamics and aeroacoustics of the Audi A6 Sportback e-tron1, his team invested almost 1,000 hours. After around 3,000 accompanying computer simulations, one thing is certain: the A6 Sportback e-tron1 is the best Audi ever in terms of aerodynamics.
The special role of aerodynamics in electric mobility
The special role of aerodynamics in electric mobility
The exceptionally low drag coefficient of 0.21 propels the A6 Sportback e-tron1 to the top of all production vehicles in the entire Volkswagen Group. The so-called Cd value serves as a measure of how streamlined an object is. The A6 Avant e-tron2 is also one of the best in its body segment, achieving a drag coefficient of 0.24. Aerodynamics play a vital role in electromobility: among other things, they determine energy efficiency, which is considered the key to the success of electric vehicles. "Our customers expect a long range, so the vehicles have to be efficient. That is why aerodynamics are important," says Islam. "In the coming years, energy efficiency will become a dominant topic in our society."
A penguin as a role model for the A6 Sportback e-tron?
A penguin as a role model for the A6 Sportback e-tron?
The aerodynamics experts also draw inspiration for the perfect silhouette from nature. According to Islam, the example of the teardrop shape is somewhat worn out, but the penguin is even more interesting. "The penguin has a very low Cd value; in the literature, you can find values between 0.06 and 0.09." However, there are limits to car design. "As long as a car has to be aesthetically pleasing and suitable for everyday use, there will be a limit that we can't go below. We are very close to that with the A6 e-tron3." The A6 Sportback e-tron1 achieves ranges of up to 756 kilometers on a single charge thanks to its outstanding aerodynamics, among other things.
Meticulous attention to detail
The basic rule for the lowest possible air resistance: "As round as possible up to the rear and as few edges as possible," says Islam. But there is more to it than that; meticulous detail work is required. "I always compare the development of a vehicle’s aerodynamics to a marathon race that lasts four to five years - there are highs and lows." Aerodynamics engineers Andreas Lauterbach and Matteo Ghelfi have now crossed the finish line with their team.
The aerodynamic refinements of the A6 Sportback e-tron
“This shape is ultimately the prerequisite for the outstanding Cd value”
A unique feature of the new A6 Sportback e-tron1 is its flat silhouette with a roof that gradually slopes down towards the rear. "This shape is ultimately the prerequisite for the outstanding Cd value," explains Islam. Then there are the many small details, such as a controllable cooling air intake, located behind a decorative grille under the Singleframe. Islam: "This allows us to control exactly how much air flows through and around the vehicle. The less airflow there is, the better." Another refinement is the headlights, which are almost flush with the outer skin. "We have optimized this area so the air flows optimally around the headlights and fenders. A little further down, there is a small opening in the bodywork: to avoid flow losses, the so-called "air curtain" directs the air from the front around the corner.
Aerodynamics: thought through from the first brushstroke
To achieve their goal, the aerodynamics experts are involved from the first brushstroke of the design team. "We discuss and help shape the vehicle and support it in terms of aerodynamics and aeroacoustics until it goes into series production," says Islam. Time and again, tests are carried out in the wind tunnel, where professional skiers occasionally train too, perfecting their posture in flight or on the descent.
"No contradiction between design and aerodynamics"
"No contradiction between design and aerodynamics"
There must be no compromises on design, one of the premium features of the four rings. "We will continue to offer our customers long range without packing cars with huge batteries," says Islam. "The Audi A6 e-tron3 is another example of the fact that there is no contradiction between good design and good aerodynamics."
