Numerical Study of a drag reduction system for a formula student car

• Main Author: Monteiro, Carlos Alexandre Bandarrinha
• Publication Date: 2021
• Format: Master thesis
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://hdl.handle.net/10362/149236
• topic: CFD; Rear Wing; Formula Studen; Drag Reduction System; DRS; Aerodynamics; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Mecânica

This dissertation focuses on utilising computational fluid dynamics tools to achieve an optimized Drag Reduction System configuration from an existent design of a Formula Student car rear wing. The considered rear wing is a multi-element wing with 3 airfoils that produces a considerable fraction of the car’s total aerodynamic downforce. This requires a downforce/drag forces trade-off that impacts the performance of the car in each segment of the race track. The introduction of a Drag Reduction System requires that the system is well design to avoid adding complexity without considerable benefits. A typical formula student DRS concept is applied where the two most rear-er flaps are rotated in order to decrease or increase drag. Achieving a good DRS system through the best possible configuration in terms of angle of attack of the flaps, as well as the center of rotation position was considered to have the potential to be a considerable improvement to the cars’ performance. In the present work StarCCM+ is used to simulate the external aerodynamics of the isolated rear wing. Simulation macros are developed in order get a better understanding of the overall force mapping of all lift and drag forces on the current rear wing configuration. Through a first force mapping study is in seen how the second flap’s angle of attack has more influence in the overall forces on the wing. The lift and drag mapping showed the expected close proximity between this separate force components. Iteratively, the best configuration in terms of angles and centers of rotation of the flap is achieved. Through a 2D analysis of the isolated airfoil it is seen that the lowest drag angle of attack is about 0. On a first iteration of optimization process the first movable flap sits at 0 while for the second flap shows that a 6 angle of attack is preferable in order to reduce drag. It is seen that varying the centers of rotation also has impact the force values although it is less than varying the angles of attack. The combination of the angles of attack study with the center of rotation showed that the preferable minimum drag configuration sits at a f lap1 = 0, a f lap2 = 6, a CORf lap1 = 20% and a CORf lap2 = 0%. The tools developed through this dissertation are left to the team in such a way that it makes it faster to achieve the iterative study of the DRS system configuration.