Department of Mechanical Engineering, IUPUI

Christina KoehlyMichael Schneider

Internship Students from GermanyIndiana University - Purdue University

Indianapolis, USA

Berufsakademie (University of Cooperative Education)

Karlsruhe, Mannheim, Germany

Faculty Advisor: Professor H. U. Akay

Aerodynamic study of Jeff Gordon’s NASCAR 2000

March 2001

Jeff Gordon’s NASCAR

(BRICKYARD 400, AUGUST 5th 2000)

Indianapolis Motor Speedway

Home of Brickyard 400

Project Objective

• Use Finite Element code ANSYS/FLOTRAN and Finite Volume code StarCD– Examination of aerodynamic behavior– Comparison of Velocity Magnitude and Static

Pressure

• Decision of which program give better results

THE PROJECT TEAM AT WORK!

Theory: Assumptions

• Incompressible Fluid• Adiabatic Conditions

• Steady State• Newtonian Fluid• Turbulent Model

Property Value Units Reynolds Number

Density 1.205 kg/m3

Dynamic Viscosity 1.81E-5 Ns/m2

Car Length 5.195843 m

1. Free Stream Velocity 35 m/s 12.17E+06

2. Free Stream Velocity 70 m/s 24.21E+06

3. Free Stream Velocity 100 m/s 34.59E+06

ANSYS/FLOTRAN and StarCD Procedure

• Define the problem

• Define Keypoints

• Make Areas from Keypoints

• Create the Finite Element Mesh

• Set Boundary Conditions

• Set Solver Parameters

• Get the results

Areas

Meshes

Boundary Conditions

• All Boundary Conditions were applied to lines

• Velocity applied to surface of the car

• Velocity of 35 m/s, 70 m/s and 100 m/s applied in x-direction to “inlet” and lower free stream surface

• Relative Pressure of 0 Pa applied to “outlet”

Parameters

• Steady-state with turbulent solver

• Fluid properties set to air in standard SI

• Solver set to perform more than 500 iterations

RESULTS

Velocity Magnitude 35 m/s

StarCD: Velocity by 35 m/s ANSYS: Velocity by 35 m/s

Velocity Magnitude 70 m/s

StarCD: Velocity by 70 m/s ANSYS: Velocity by 70 m/s

Velocity Magnitude 100 m/s

StarCD: Velocity by 100 m/s ANSYS: Velocity by 100 m/s

Static Pressure 35 m/s

StarCD: Pressure by 35 m/s ANSYS: Pressure by 35 m/s

Static Pressure 70 m/s

StarCD: Pressure by 70 m/s ANSYS: Pressure by 70 m/s

Static Pressure 100 m/s

StarCD: Pressure by 100 m/s ANSYS: Pressure by 100 m/s

Conclusion

• Both programs are good to solve these problems

• For easy geometries ANSYS/FLOTRAN should be used to get fast results

• For complex geometries StarCD gives more reasonable results, but it takes more time to define the boundary conditions

THE END!