Formula SAE Aerodynamics: Design process with focus on drivability 2015-36-0359
This paper presents the design process of an aerodynamic kit for a Formula SAE competition vehicle using CFD with special attention to the distribution of aerodynamic loads. The methodology for the development of concepts is to create a boundary that respects the geometric constraints of the vehicle and also complies with FSAE 2015/16 Rules. Inside these boundaries different geometries of aerodynamic accessories can be analyzed and several full vehicle models can be created. The initial model is conceived based on the literature and then analyzed with CFD to generate another model. The process is repeated until it reaches a model that cannot be considered optimum but is close enough to the targets previously defined. The governing equations for the numerical simulation are presented as well as the reason for their use. The simplifications in the CAD model are explained and the domain is then discretized in predominantly hexahedral elements with orthogonal prismatic cells next to wall surfaces. Another difference is that the airfoil profiles used are specifically designed for racing vehicles. The most relevant parameters in multi element profiles (slots, AoA) have been optimized and show good agreement with wind-tunnel validated studies as shown by the literature used. After the CFD analysis is completed and the final concept defined, the gains due to the aerodynamic kit are quantified based on lap time simulations. Finally the performance on the track with and without the kit is evaluated and gg diagrams are made with the data acquired. Additionally, simple flow visualization techniques are used and described.