Race Car Aerodynamics Turbulence

SESA6039 Race Car Aerodynamics Laboratory Exercise 2

Abstract

The flow past a front wing element is simulated two-dimensionally in FLUENT. The variation of aerodynamic forces with height and angle of attack were observed. The resultant increase in aerodynamic efficiency with decrease in ride height and decrease in efficiency with increasing angles of attack is quantified and explained with the aid of contour plots obtained for static pressure and velocity. The key role of y+ and courant number in computational fluid dynamics problems is also explained.

Table of Contents

Abstract        

Nomenclature        

Introduction        

Method        

Numerical Model        

Grid Meshing        

Boundary Conditions        

Boundary conditions for ground effect cases        

Boundary conditions for freestream cases        

Results        

Freestream cases        

        [pic 1]

        [pic 2]

        [pic 3]

Wing in ground effect        

h/c = 0.25        

h/c = 1        

Unsteady flow at         [pic 4]

Courant number        

Conclusion        

References        

List of Figures and Tables        

Nomenclature

WIG – Wing in ground

Re - Reynolds number

U∞ - Freestream velocity

RANS – Reynolds Averaged Navier Stokes

AoA - Angle of attack

c - Aerofoil chord  

h – Distance from the moving ground

RMS – Root mean squared

CL – Coefficient of lift

CD – Coefficient of drag

P – Pressure

v – Velocity

CFD – Computational Fluid Dynamics

Introduction

The flow past a Tyrell 098 main front wing element was simulated using the CFD program FLUENT. The wing element was placed in freestream at three different angles of attack (AoA) and two cases in close proximity to the moving ground. A low speed flow passing a downforce generating wing both in and out of ground effect was modelled.  Several physical features were investigated including downforce and drag and its variation with height and angle of attack. Unsteady freestream simulations were also examined at higher angles of attack. The aerofoil was modelled in 2D to allow for swift grid generation, easy specification of the boundary conditions and significantly shorter solution times.