University of Texas at El Paso DigitalCommons@UTEP Open Access Theses & Dissertations 2016-01-01 Analysis of Road Vehicle Aerodynamics with Computational Fluid Dynamics Christian Armando Mata University of Texas at El Paso, [email protected] Follow this and additional works at: https://digitalcommons.utep.edu/open_etd Part of the Aerospace Engineering Commons, and the Mechanical Engineering Commons Recommended Citation Mata, Christian Armando, "Analysis of Road Vehicle Aerodynamics with Computational Fluid Dynamics" (2016). Open Access Theses & Dissertations. 894. https://digitalcommons.utep.edu/open_etd/894 This is brought to you for free and open access by DigitalCommons@UTEP. It has been accepted for inclusion in Open Access Theses & Dissertations by an authorized administrator of DigitalCommons@UTEP. For more information, please contact [email protected]. ANALYSIS OF ROAD VEHICLE AERODYNAMICS WITH COMPUTATIONAL FLUID DYNAMICS CHRISTIAN ARMANDO MATA Master’s Program in Mechanical Engineering APPROVED: Jack Chessa, Ph.D., Chair Norman D Love, Ph.D. Bill Tseng, Ph.D. Charles Ambler, Ph.D. Interim Dean of the Graduate School Copyright © by Christian A. Mata 2016 Dedication I would like to dedicate this work, to my mother, father, and brother. With their support and the support of my loved ones, that make this possible. Thank you for all you have given me, and for always being there for me. ANALYSIS OF ROAD VEHICLE AERODYNAMICS WITH COMPUTATIONAL FLUID DYNAMICS by CHRISTIAN ARMANDO MATA, B.S. THESIS Presented to the Faculty of the Graduate School of The University of Texas at El Paso in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE Department of Mechanical Engineering THE UNIVERSITY OF TEXAS AT EL PASO May 2016 Acknowledgements I would like to thank my graduate advisor Dr. Jack Chessa. Your guidance and assistance have made this possible. I would also like to thank Cyrus Proctor who is part of the support team from the Texas Advanced Computing Center (TACC). Finally, Special thanks to Abigail Arrington, Shannon Earls, and Michael Barton, from Altair-Hyperworks. v Table of Contents Acknowledgements ....................................................................................................................v Table of Contents ..................................................................................................................... vi List of Tables ......................................................................................................................... viii List of Figures .......................................................................................................................... ix Chapter 1: Background and Theory ...........................................................................................1 1.1 Introduction ..............................................................................................................1 1.2 Shell Eco Marathon..................................................................................................1 1.3 Effects on Vehicle Performance ..............................................................................2 1.4 Background Theory .................................................................................................3 1.5 Computational Fluid Dynamics ...............................................................................6 1.6 Richardson Extrapolation.........................................................................................7 1.7 High Power Computing ...........................................................................................8 Chapter 2: Validation ...............................................................................................................10 2.1 Theoretical Drag ....................................................................................................10 2.2 Fluid Domain .........................................................................................................13 2.3 Boundary Layer .....................................................................................................14 2.4 Mesh Refinement ...................................................................................................16 2.5 Ideal Simulation Parameters ..................................................................................18 Chapter 3: Wheels In vs Wheels Out .......................................................................................19 3.1 Introduction and Background ................................................................................19 3.1 Wheels Out.............................................................................................................22 3.1.1 Drag of Wheels ......................................................................................................24 3.1.2 Total Drag ..............................................................................................................26 3.2 Wheels In ...............................................................................................................26 3.3 Simulation of Wheels Out and Wheels In ..............................................................28 3.3.1 Vehicle Model ........................................................................................................28 3.3.2 Meshing of Vehicle ................................................................................................31 vi 3.4 Fluid Simulation.....................................................................................................33 3.4.1 Pre-Processing........................................................................................................33 3.5 Solving ...................................................................................................................35 3.6 Results ....................................................................................................................35 3.6.1 Results of Wheels Out ...........................................................................................36 3.6.2 Results of Wheels In ..............................................................................................42 3.7 Conclusion .............................................................................................................46 Chapter 4: Vehicle Height .......................................................................................................47 4.1 Introduction and Background ................................................................................47 4.1.1 Vehicle Nose and Tail ............................................................................................47 4.1.2 Ground Effects and Venturi ...................................................................................48 4.2 Vehicle Modeling...................................................................................................49 4.3 Model Meshing ......................................................................................................50 4.4 Results ....................................................................................................................51 4.5 Conclusion .............................................................................................................56 References ................................................................................................................................57 Appendix ..................................................................................................................................59 Curriculum Vita .......................................................................................................................67 vii List of Tables Table 2.1: resulting values for the mesh independence study ...................................................... 17 viii List of Figures Figure 1.1: Pie graph generated by matlab code ............................................................................. 3 Figure 1.1: The different components of the Boundary Layer 2. .................................................... 5 Figure 2.1: Drag coefficient of a sphere relative to the Reynolds number 2 ................................. 11 Figure 2.2: Mesh of Sphere ........................................................................................................... 13 Figure 2.3: Plot of Resulting Drag Coefficient against ratio W/D. ............................................. 14 Figure 2.4: Boundary layer refinement ......................................................................................... 15 Figure 2.5: Drag coefficient against number of layers ................................................................. 15 Figure 2.6: Comparison of 2 layers and 10 layers ........................................................................ 16 Figure 2.7: results for the Richardson extrapolation from a Mathematica code ........................... 17 Figure 3.1: Example of Heading 10. .............................................................................................. 21 Figure 3.2: Plot of the Drag Coefficient of an Ellipsoid 13. ......................................................... 23 Figure 3.3: Values of Drag coefficient for a relative Reynolds Number for a sphere 3. ............... 25 Figure 3.4: Vehicle Model of open wheel vehicle. ....................................................................... 28 Figure 3.5: Cross Sectional view