The development of a new car’s aerodynamics begins with studies that propose measures to improve that model’s features. The core work initially takes place in the virtual environment of simulation programs assisted by CFD (computational fluid dynamics, which examines the flow – ed.). “We do around 80 percent of our work with this method. Thanks to its accuracy, we make important decisions based on the simulation results”, says Pavla Polická from EBW – Aerodynamics.
One of the proposed measures involved using an active aerodynamic element – the so-called cooling blinds. Its wide application was used on the OCTAVIA for the first time. “It is a very demanding solution, which we developed from the beginning in cooperation with engine specialists”, says Vojtěch Hudeček on behalf of the aerodynamics development team. The four plates can close air access to the lower part of the radiator and, thus, improve the air flowing around. “The solution saves emissions, as well as our customers’ money”, he adds.
Quite early on, at the stage when a number of other simulations are still underway, full-size models start to be measured. They are made of foam, from which the shape of the car body is milled. However, it is important that, for example, the engine compartment is fully engineered, as it has a significant effect on aerodynamics.
Aerodynamic forces in the vehicle’s rear are not only affected by the design of that specific part. Everything is related to everything, so some effects from the front can have a negative effect only in the back. “Although two different teams participated in the OCTAVIA liftback and estate models, they had to work together so that their requirements in certain parts of the body did not damage the other body variant”, say team leaders Vojtěch Jakubec and Vojtěch Hudeček. The result of the cooperation is obvious: Both body variants are aerodynamically excellent.
Wheels are also a kind of rocket science. “In cooperation with the design team, we’ve ensured that they are both aerodynamic and beautiful”, says Jakubec, giving a compliment. In addition to CFD simulations, ŠKODA AUTO also uses a unique technological solution in wheel development, which allows various wheel shapes made with 3D printing to be quickly tested in the wind tunnel. Vehicle properties are influenced by every design element, even the rim size. Owing to emission reporting, the WLTP standard then requires that all variants be tested.
Complete vehicle prototypes are worked with in one of the last stages of aerodynamics development. One of the things tested in the wind tunnel by using a contrasting colour is the way water runs down the body. It is necessary to make sure that the driver has a good view of the wing mirrors through the side windows.
The final work done by the aerodynamics team is usually to take measurements of pre-production cars in the wind tunnel in order to homologate each version. For this purpose, ŠKODA AUTO uses Volkswagen’s and Audi’s tunnels, as well as the tunnel of the University of Stuttgart.