Aerodynamics of a 2017 Formula 1 Car: Numerical Analysis of a Baseline Vehicle and Design Improvements in Freestream and Wake Flows

In this work an extensive numerical analysis of open-wheeled racing car aerodynamics is presented. The whole CFD workflow, from meshing to calculation, was carried out by the open-source software OpenFOAM®, in the steady RANS framework. After investigating the mechanisms behind ground effect by means of simple test cases, including a diffuser-equipped blunt body and a single element wing, attention was focused on the 2017 Formula 1 car designed by the British constructor ©PERRINN. The validation of the numerical results in terms of drag, downforce, efficiency and front balance was accompanied by a qualitative study of the flow around the car. Axial vorticity plays a key role in the generation of downforce and the use of ground effect improves the efficiency of the overall vehicle. In the second step of the research, it was found that front and rear ride height have a strong influence on the dynamic behaviour of the car. Since racing implies a close interaction with other vehicles, the core of the research was devoted to evaluation and subsequent improvement of aerodynamic performance in wake flows. Tandem-running simulations at different distances between lead and following cars put in evidence that running in slipstream results in a strong worsening of downforce and a dramatic change in front balance. To overcome these limitations, the baseline vehicle was subjected to a targeted aerodynamic development. Among the tested aero packages, one in particular provided encouraging results: it ensures higher downforce and efficiency than the baseline configuration while fulfilling, at the same time, the goal of reducing the above mentioned performance worsening in slipstream. The concepts behind the effectiveness of the new design deal with a better management of the chaotic flow underneath the car; moreover, underbody and rear wing adjustments contribute to generation of a shorter and narrower wake. Overall, an easier approach to the lead car and a safer overtaking could be achieved through small modifications to 2017 F1 Technical Regulations, without disrupting the current F1 car layout. As a further check of the robustness of the new design proposals, all the developed aerodynamic configurations have been tested in yawed flow. Finally, the last section of the research aimed at quantifying the lap-time performance of the vehicles equipped with the new aero packages, since each track requires specific levels of downforce and efficiency. Results in terms of aerodynamic specifications are in line with those typically encountered in current F1 grand prix races.