Studying vehicles subjected to the flow in a wind tunnel is a simplified representation of driving on the road. By simulating the ground and wheel rotation, we approximate reality as closely as possible. However, the results are still slightly affected by the test environment. Some of these interference effects result from different boundary conditions in the wind tunnel, which are influenced, for example, by the shape of the wind tunnel test section. Typically, overly large forces are measured in closed test sections and overly small forces are measured in open test sections.

Validated correction methods for the interference effects occurring in wind tunnels with closed test sections have been available for some time now, and are applied as standard in many wind tunnels. In comparison, the efficient application of correction methods for wind tunnels with open test sections is considerably more difficult. Therefore, the work at FKFS to develop more user-friendly wind tunnel correction methods for open test sections represents an important area of focus for wind tunnel research.

Should our customers request it, we can use the most up-to-date iteration of the established Mercker-Wiedemann method for measurements in the aeroacoustic vehicle wind tunnel and in the model wind tunnel to correct the aforementioned wind tunnel interference effects – and also develop correction procedures for customer wind tunnels.

A vehicle's air resistance is a component of the vehicle's driving resistances and is therefore directly related to consumption. In addition to the air resistance, other parameters in aerodynamic vehicle development are the axle lifts and sensitivity to crosswinds. The aim of aerodynamic optimization is to achieve the various target values by modifying the shape. In general, passive measures can be used here in the visible and non-visible regions (e.g. undercarriage). The undercarriage and the rotating wheels are responsible for up to 30 % of the overall air resistance.

Thorough technical and scientific knowledge, access to the aerodynamic test facilities and computing resources at FKFS, plus years of experience from automotive industry research and development projects guarantee that our customers' projects are managed with focus and efficiency. It goes without saying that we do all this while maintaining absolute confidentiality.

FKFS is also conducting research on methods and measures to actively influence the flow, in order to reduce air resistance beyond what is currently possible by conventional means.

The engine compartment, the exhaust system and the air flow through and around them are particularly important for heat protection investigations. Since experimental investigations with available hardware is only possible at a very late stage, computational simulations offer time and cost advantages – especially in the early stages of a project. We use the latest RANS and Lattice-Boltzmann methods for our simulation.

3D programs for simulating heat conduction and radiation – such as PowerTHERM® – are generally used to calculate component temperatures. One example is the calculation of the temperature distribution on the engine mounts in direct proximity to an exhaust system. Using interfaces, convective heat flows can be transported from the CFD calculation to the thermal solver cell-by-cell.

The materials' thermal properties are important input parameters for simulations. To increase the accuracy of our simulations, FKFS operates a thermal material analysis laboratory.