Verification of a flow simulation
Delta Racing (DR) is a student initiative at the Mannheim University of Applied Sciences, which participates in the international Formula Student competitions with self-built racing cars.
After the first simulations had been carried out to simulate the flow around the racing car, the first wind tunnel measurements were started in 2014 on a model that had been produced in the classical way with the university's machine tools. In order to have enough time for optimization work within the short season, the first model using the 3D printing process was produced in the following 2015 season in cooperation and with the support of BASF SE. As a result, the time required could be reduced from half a year to two months.
The aerodynamic package of the current racing car includes a front and rear wing, an underbody diffuser and flow-optimized side boxes. The purpose of these components is to generate a negative downforce. This increases the tire contact force without increasing the mass of the vehicle, enabling better lap times due to higher cornering speeds. Another goal was to minimize air resistance and thus reduce fuel consumption.
| CFD | Wind tunnel | |
|---|---|---|
| Lift-coefficient | -1,15 | -1,15 |
| Drag-coefficient | 0,85 | 0,73 |
On the basis of concept studies, the target variables lift and drag coefficients were calculated using numerical flow simulations. Once the optimal design was found, the simulation results were verified in the wind tunnel. For better comparison, the two-dimensional velocity field was recorded in several planes using the "Particle Image Velocimetry" (PIV) measurement method. The results of the measurement and simulation are shown in the figures above. Since the experimental data are in good agreement with the numerically determined values, pre-development work can be regarded as confirmed, so that in the next step the components can be manufactured on a real scale.
