Mercedes-Benz unveiled the “Concept IAA” (Intelligent Aerodynamic Automobile) at the Frankfurt Motor Show. The study switches automatically from a four-door coupé with a fascinating design to an aerodynamic world record breaker with a Cd figure of 0.19 when the vehicle reaches a speed of 80 km/h (50 mph), at which point numerous aerodynamics measures alter the shape of the vehicle.
At the rear end, eight segments deploy, extending the length of the car by up to 390 mm; front flaps in the front bumper extend outwards by 25 mm and rearwards by 200 mm, improving airflow around the front end and the front wheel arches; the active wheel rims change their cupping from 50 mm to zero; and the fin in the front bumper retracts by 60 mm to improve flow along the underbody.
Mercedes-Benz said that the “Concept IAA” exemplifies the fundamental technological changes which are taking place in the automobile industry. The primary driving force behind this process of change is digitization—referred to in a business context as “Industry 4.0”. (Earlier post.)
The design and aerodynamic shaping of the concept would not have been possible without the systematic digital networking of different specialist departments. The designers have employed the latest algorithmic design methods to handle the complex geometric design. The individually adapted software enables dynamic design in three-dimensional space. This dynamic modeling makes it possible to display and model different states simultaneously. The resultant highly complex geometries were turned into reality with the aid of innovative production technologies (rapid prototyping).
The aerodynamics were developed with numerical flow simulation. Mercedes-Benz aerodynamics experts used around one million CPU hours to simulate the airflow, working through around 300 variants. The work involved is roughly equivalent to that required to develop a production model.
The Concept IAA is 5040 millimeters long (5430 mm in aerodynamic mode), 1995 mm wide and 1305 mm high. Its wheelbase measures 2975 mm, and the front/rear track widths are 1710 and 1770 mm respectively.
The concept car is powered by a gasoline/electric plug-in hybrid drive with a total output of 205 kW (279 hp). This provides it with a top speed of 250 km/h (155 mph), electronically limited.
CO2 emissions and electric range depend on the mode in which the vehicle is tested: in aerodynamic mode the concept manages an all-electric range of 66 kilometers (41 miles) and emits 28 g CO2 per km. In design mode the range stands at 62 km (38.5 miles) and CO2 emissions at 31 g per km.
As slower-speed urban driving is accorded a two-thirds weighting in the current New European Driving Cycle (NEDC), the advantage of aerodynamic mode is not revealed as clearly in this test as in real-life driving, Mercedes-Benz noted.
The Concept IAA also offers a glimpse of future in areas not immediately apparent. The study is equipped with a large number of sensors and modules that enable autonomous driving and car-to-x communication.