Methodological approach for virtual aerodynamic development of a racing car

Nowadays, analytical aerodynamic studies have become increasingly popular and important to understand how a vehicle should behave in real life. Depending on the type of car being studied, the focus is on different factors, such as downforce or drag or aerodynamic efficiency. In general, the most important topic for road vehicle is to reduce the fuel consumption while, for racing car, the focus is also on the contribution of downforce, depending on the type of racetrack. In order to reduce design processing time, the use of aerodynamic software to simulate aerodynamic behavior and replace experimental studies in the early development phase has become widespread in recent years. In fact, if a correct CFD simulation model is created that verisimilarly recreates real-life conditions, new configurations and designs of the same car can be found and studied in less time. The subject of this Master's Thesis is the simulation of models that are commonly used in a company to validate the CFD model and try to correlate the numerical and physical results measured experimentally. The two models mentioned are: the Ahmed Body and the DrivAer model. Different configurations have been analyzed considering different mesh types and refinement zones in order to obtain results in line with wind tunnel data. The sensitivity study aims to create a model that represents a good compromise between accuracy and computational cost. In addition, a detailed comparison will be made between the results obtained from Altair CFD solvers: AcusolveTM, based on finite element method and more accurate but costly in terms of computational effort, and UltraFluidX, based on Lattice Boltzmann method, which is much faster and less dependent on the quality of the surface mesh of the geometry examined. The aim of this evaluation is to understand the potential of UltraFluidX in terms of fast optimization cycle, while also assessing its ability to determine the aerodynamic performance correlated to experimental data. In the end, a consolidated process has been proposed with the usage of UltraFluidX for optimization and AcusolveTM for results validation. This method has been applied to create an Aerokit for a single-seater racing car in order to achieve the main targets: to increment the tire grip of the car with downforce generation, monitoring the drag contribution, and to obtain a good balance between front and rear part of the car with a proper aerodynamic efficiency. In conclusion, the workflow, established by this Master’s Thesis, confirms the effectiveness of UltraFluidX in testing several different vehicle configurations, while AcusolveTM analysis is mandatory to validate the effective drag and downforce performance.