nascar

Aerodynamic study of Jeff Gordon’s NASCAR 2000 Christina Koehly Michael Schneider Indiana University - Purdue University Indianapolis, USA Internship Students from Germany Berufsakademie (University of Cooperative Education) Karlsruhe, Mannheim, Germany Faculty Advisor: Professor H. U. Akay Department of Mechanical Engineering, IUPUI 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 • Steady State • Newtonian Fluid • Turbulent Model Property Density Dynamic Viscosity Car Length 1.205 1.81E-5 5.195843 • Incompressible Fluid • Adiabatic Conditions Value Units kg/m3 Ns/m2 m Reynolds Number 1. Free Stream Velocity 2. Free Stream Velocity 3. Free Stream Velocity 35 70 100 m/s m/s m/s 12.17E+06 24.21E+06 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!