EFFECT OF AERODYNAMIC FORCES ON AN EXPOSED WHEEL OF RACING CARS

Abstract

The thesis is dedicated to investigate the dynamic effect of wheel rotation on the aerodynamic coefficients of dry and wet-condition wheels of Formula One racing cars. The study includes the evaluation of the tread design of wet-condition wheel as a parametric study. A CFD approach was used to investigate the forces acting on the wheel. This was performed using the Ansys Fluent CFD package. In spite of the high level of confidence in the Ansys simulation package, a validation work should be done. In this validation work, the coefficient of pressure on the dry wheel circumference at middle plane was selected as an experimental data from literatures. A comparison between the computed results and the experimental ones have been accomplished and showed good agreement. Another computational model of Formula One racing car rotating wet-condition wheel in contact with the ground is studied as the main case study. The validation work supported the main case study by defining the most reliable conditions of testing such as the optimal mesh method and size, the computational domain size, and the best turbulence model. The wet-condition wheel case was modeled using Rotating Reference Frame in order to simulate the dynamic effect of its rotation. The value of resistive torque was computed for each wheel model (dry and wet-condition). Also, a parametric study on the tread design of the wet-condition wheel was performed by varying the tread depth (h) and the pitch angle (θp) of the tread elements. In addition, general schematic pictures of the flow behavior around the wet-condition wheel are presented. The main conclusions reached in this study are summarized into three main points: Ansys Fluent can be used to produce realistic results using the dynamic analysis of the flow around dry rotating wheel in contact with a moving ground. In general, it shows good agreement to the experimental work in the verification case study. In addition, in the case of rotating wet-condition wheels in contact with a moving ground, it shows reasonable outcomes related to flow physics. The realizable k-ε model with the non-linear wall treatment