|Tipo di tesi||Tesi di laurea magistrale|
|Titolo||Studio aerodinamico del modello DrivAer: l'influenza dei wheel deflector|
|Titolo in inglese||Aerodynamic Analysis of the DrivAer Car Model: The Impact of Wheel Deflectors|
|Struttura||Dipartimento di Ingegneria "Enzo Ferrari"|
|Corso di studi||Ingegneria Del Veicolo (D.M.270/04)|
|Data inizio appello||2021-12-02|
|Disponibilità||Accessibile via web (tutti i file della tesi sono accessibili)|
Lo scopo di questa tesi è analizzare diverse geometrie dei wheel deflector e studiare il loro impatto sulla resistenza totale del veicolo.
The purpose of this thesis is to analyse different geometries of wheel deflectors and to study their impact on the total resistance of the vehicle. A detailed study was carried out considering a stationary insulated wheel and a rotating insulated wheel with a certain angular speed. In both cases, a careful analysis of the flow around the wheel was carried out, calculating the aerodynamic coefficients: coefficient of resistance Cd, coefficient of lift Cl and the coefficient of pressure Cp. This analysis allowed to validate the results of fluid dynamics simulations by comparing them with those in the literature. Subsequently, a careful comparison was made between the stationary wheel and the rotating wheel. It has been shown that the same rotated wheel has considerable differences compared to when it is stationary. The following is an aerodynamic study of the reference model to quantitatively assess the impact of different wheel deflector geometries. It is the Drivaer model developed by the University of Munich. The wheels are subjected to an angular velocity and the floor of the computational domain is moving with velocity equal to that one of undisturbed flow. These conditions must necessarily be applied to better represent reality and have a correct representation of the flow around the vehicle. The main objectives are: • calculate the coefficient of resistance of the vehicle; • plotting the pressure coefficient at the top and bottom of the vehicle (considering the centre section); • plotting the pressure coefficient on the tyre surface considering the centreline section. The coefficient of resistance obtained from fluid dynamics simulation has been compared with the experimental one and the one deriving from a URANS simulation present in the literature. A relative error has been calculated between the resistance coefficient, derived from the simulation, and the experimental one of about 1%. Subsequently, several geometries of two wheel deflectors positioned in front of the front wheels of the vehicle were introduced. Again, the same curves as described above were plotted and compared with the reference model (car without wheel deflectors). Based on the geometry used, different results were obtained in terms of the distribution of the pressure coefficient and the resistance coefficient. The common aspect to all of the configurations studied is the reduction of the coefficient of resistance of the vehicle. In fact, thanks to the introduction of these wheel deflectors, the coefficient of resistance is reduced by about 2-5 %. The main effect of wheel deflectors is to reduce the high-pressure region placed in the front of the tyres near the ground. The best results were obtained with three-dimensional geometries with which the coefficient of resistance of the vehicle decreased by about 4-5 %. Finally, the same configurations introduced earlier were studied but adding two wheel deflectors in front of the rear wheels of the vehicle. In order to reduce the high-pressure area at the front of the tires, the two rear deflector wheels moved further back. In this way, in almost all cases, an improvement in performance is observed: the drag coefficient of the vehicle decreases compared to the configurations previously studied.