IJSRD - International Journal for Scientific Research & Development Vol. 3, Issue 02, 2015 ISSN (online): 2321-0613 Computational Fluid Flow Analysis of Formula One Racing Car Triya Nanalal Vadgama 1 Mr. Arpit Patel 2 Dr. Dipali Thakkar 3 Mr. Jignesh Vala 4 1 Student 2,4 Assistant Professor 3 Head & Professor 1,2,3,4 Department of Aeronautical Engineering 1,2,3,4 Sardar Vallabhbhai Patel Institute of Technology, Vasad, Gujarat Technological University, Abstract A modern Formula One (F1) Racing Car has almost as much in common with an aircraft as it does with an ordinary road car. Aerodynamics has become a key to success in the sport and teams spend millions of dollars on research and development in the field each year for improving performance. The aerodynamic designer has two primary concerns: 1) the creation of down force, to help push the car s tyres onto the track and improve cornering forces, 2) to minimise the drag that occurs due to turbulence and acts to slow down the car. In this project, various features of the car will be enhanced to make the whole car more aerodynamically efficient, by designing and modifying and the different parts of the car-body chassis, and analysing the corresponding flow-field at different velocities and Angle of Attacks (AOA) using Ansys CFX software. The enhanced model will be made aerodynamically efficient by considering the contours of velocity, pressure, and streamlines. Key words: Formula One race car, Airfoil, Aerodynamics, Computational Fluid Flow, Angle of Attack I. INTRODUCTION On the surface, automobile racing appears simply as a popular sport. But in reality, racing serves as a proving ground for new technology and a battlefield for the giants of automobile industry. Although human factors are frequently publicized as the reason behind the success or failure of one racing team or another, engine power, tire adhesion, chassis design, and recently, aerodynamics probably play a very important role in winning this technology race. Aerodynamics is study of gases in motion. As the principal application of aerodynamics is the design of aircraft, air is the gas with which the science is most concerned. Although aerodynamics is primarily concerned with flight, its principles are also used in designing automobile. The wind tunnel is one of the aerodynamicist's basic experimental tools. However in recent years, it has been supplanted by the simulation of aerodynamic forces during the computer-aided design of aircraft and automobiles. A. Work Plan: Analysing the Computational Fluid Flow over the following components of the car: 1) Front Wing Airfoil (NACA 4412) & Rear Wing Airfoil (NACA 2408) : a. Negative (-15 0 ) AOA : Free stream velocity of 30 kmph Free stream velocity of 320 kmph b. Zero (-0 0 ) AOA : Free stream velocity of 30 kmph Free stream velocity of 320 kmph Ahmedabad, India c. Positive (+15 0 ) AOA : Free stream velocity of 30 kmph Free stream velocity of 320 kmph 2) Front Wing Assembly & Rear Wing Assembly : a. Negative (-15 0 ) AOA : b. Zero (-0 0 ) AOA : Refer [1] for the CAD Modelling phase of all the project. B. Selection of Airfoil: NACA 4-series airfoils are the most widely used airfoils for Formula One race cars. The NACA four-digit wing sections define the profile by: 1) First digit - maximum camber as percentage of the chord. 2) Second digit - the distance of maximum camber from the airfoil leading edge in tens of percentage of the chord. 3) Last two digits - maximum thickness of the airfoil as a percentage of the chord. 1) Front Wing Airfoil NACA 4412: The Front Wing of a Formula One car creates about 25% of the total car s downforce. This is one of the most widely used spoiler airfoil, but needs to be enhanced as per speed. Such a thicker airfoil is used to obtain the desired higher downforce from the front end of the car, at a given speed. Fig. 1: NACA 4412 2) Rear Wing Airfoil NACA 2408 Due to location of engine at the rear end of the car, more downforce is generated. Hence, to compensate for minimization of downforce from rear end, a thinner airfoil is used. Thinner airfoil also helps to maintain the continuity of the flow without flow separation. Thus, NACA 2408 is employed at the rear end. Fig. 2: NACA 2408 C. Computational Fluid Dynamics Background: Computational fluid dynamics, usually abbreviated as CFD, is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows. Computers are used to perform the calculations required to simulate the interaction of liquids and gases with surfaces defined by boundary conditions. With high-speed All rights reserved by www.ijsrd.com 1929
supercomputers, better solutions can be achieved. The integration of the latest CFD research has transformed the way Formula One design teams work. A decade ago, engineers would test their parts using just a wind tunnel, a process requiring a large amount of patience and experience. Every small modification would require the creation of a new part, costing both time and money. Now, Formula One teams can use CFD to rapidly try out new ideas without having to physically build new parts and test them in the tunnel, allowing them to get innovative car components on to the track much quicker than ever before. CFD has increasingly become an affordable alternative to physical analysis, such as wind tunnels. The total cost of license purchasing for the CFD software is generally less than the components needed to construct a high quality experimental facility, yet is still relatively costly. As long as the advantages and restrictions are considered for the testing technique chosen, CFD can provide an accurate flow representation. There are four main advantages of CFD : 1) Its significant savings of lead times and implementation costs of new designs. 2) The capability to analyse models where controlled experiments are not viable. 3) The capability to test models in situations that would be considered hazardous. 4) The limitless degree of detail (resource dependent). II. COMPUTATIONAL FLUID FLOW ANALYSIS USING ANSYS WORKBENCH 14.0 CFX A. Front Wing Airfoil (NACA 4412): 1) Geometry: Length of Airfoil = 576 mm Width of Airfoil = 119.98 mm Length X of Enclosure = 450.05 mm Length Y of Enclosure = 215.35 mm Length Z of Enclosure = 676 mm Fig. 3: NACA 4412 Enclosed Into an Enclosure 2) Mesh: Patch Conformal Method Tetrahedrons Body Sizing of 5 mm Inflation on Airfoil boundary (Maximum Layers = 15 Growth Rate = 0.7) Mapped Face Meshing on Airfoil Faces Fig. 5: Inlet 3) CFX Setup: (Fluid Domain) Named Selections = Inlet, Outlet, Boundary Wall, Airfoil Wall Fig. 6: Outlet Reference Pressure = 1 atm Turbulence model = SST Inlet Normal Speed (Subsonic) = 30kmph/ 100kmph/ 320kmph Outlet Flow Regime = Subsonic Outlet Relative Pressure = 0 atm Free Slip Wall condition for Boundary Wall and Airfoil Wall The SST (Shear Stress Transport) turbulence model is selected for all the analysis in order to have more accuracy in results and make it possible to calculate stress during the Static Structural Analysis phase. The calculation of shear stresses, and henceforth the Force Reaction, is not possible when the k-epsilon model is used. Although the former model is as economical as the widely used latter one, accuracy for separated flows along with a wide range of flows and near-wall mesh conditions is more when SST is employed. B. Rear Wing Airfoil (NACA 2408): 1) Geometry: Length of Airfoil = 385 mm Width of Airfoil = 240 mm Length X of Enclosure = 470.01 mm Fig. 4: Generated Mesh Fig. 7: NACA 2408 Enclosed Into An Enclosure Length Y of Enclosure = 220.69 mm Length Z of Enclosure = 485 mm 2) Mesh: Patch Conformal Method Tetrahedrons Body Sizing of 5 mm All rights reserved by www.ijsrd.com 1930
Inflation on Airfoil boundary (Maximum Layers = 8 Growth Rate = 0.7) 2) Mesh: Patch Conformal Method Tetrahedrons Body Sizing of 10 mm Mapped Face Meshing on Airfoil Faces Fig. 8: Generated Mesh 3) CFX Setup: (Fluid Domain) Named Selections = Inlet, Outlet, Boundary Wall, Airfoil Wall Fig. 9: Inlet Fig. 12: Cross-Section of the Generated Mesh 3) CFX Setup: Number of Domains = 2 (Air and Front Wing) Named Selection = Inlet, Opening, Ground, Front Wing For Domain : Air Type = Fluid Reference Pressure = 1 atm Turbulence model = SST Inlet Normal Speed (Subsonic) = 100kmph Outlet Flow Regime = Subsonic Outlet Relative Pressure = 0 atm Free Slip Wall condition for Ground and Front Wing For Domain: Front Wing Type = Solid Adiabatic Heat Transfer Fig. 10: Outlet Reference Pressure = 1 atm Turbulence model = SST Inlet Normal Speed (Subsonic) = 30kmph/ 100kmph/ 320kmph Outlet Flow Regime = Subsonic Outlet Relative Pressure = 0 atm Free Slip Wall condition for Boundary Wall and Airfoil Wall C. Front Wing Assembly (6 PLATES OF NACA 4412): 1) Geometry: Length X of Assembly = 1796 mm Length Y of Assembly = 313.2 mm Length Z of Assembly = 380 mm Length X of Enclosure = 1896 mm Length Y of Enclosure = 430.2 mm Length Z of Enclosure = 680 mm Fig. 11: Assembly Enclosed Into An Enclosure Fig. 13: Inlet Fig. 14: Opening D. Rear Wing Assembly (2 PLATES OF NACA 2408): 1) Geometry: Length X of Assembly = 455 mm Length Y of Assembly = 797.75 mm Length Z of Assembly = 664.4 mm Length X of Enclosure = 595 mm Length Y of Enclosure = 1017.7 mm Length Z of Enclosure = 984.41 mm All rights reserved by www.ijsrd.com 1931
III. RESULTS A. Front Wing Airfoil (NACA 4412): 1) Negative (-15 0 ) AOA: General trend noticed for velocity and pressure contours: Fig. 15: Assembly Enclosed Into An Enclosure 2) Mesh: Patch Conformal Method Tetrahedrons Body Sizing of 10 mm Fig. 19: Velocity Contours Fig. 16: Generated Mesh 3) CFX Setup: Number of Domains = 2 (Air and Front Wing) Named Selection = Inlet, Opening, Ground, Front Wing For Domain : Air Type = Fluid Reference Pressure = 1 atm Turbulence model = SST Inlet Normal Speed (Subsonic) = 100kmph Outlet Flow Regime = Subsonic Outlet Relative Pressure = 0 atm Free Slip Wall condition for Ground and Front Wing For Domain : Front Wing Type = Solid Adiabatic Heat Transfer Fig. 20: Pressure Contours 2) Zero (0 0 ) AOA : Fig. 21: Velocity Contours Fig. 17: Inlet Fig. 22: Pressure Contours 3) Positive (+15 0 ) AOA : Fig. 18: Opening All rights reserved by www.ijsrd.com 1932
Fig. 23: Velocity Contours Fig. 27: Velocity Contours Fig. 24: Pressure Contours B. Rear Wing Airfoil (NACA 2408): 1) Negative (-15 0 ) AOA: Fig. 28: Pressure Contours 3) Positive (+15 0 ) AOA : Fig. 25: Velocity Contours Fig. 29: Velocity Contours Fig. 26: Pressure Contours 2) Zero (0 0 ) AOA : Fig. 30: Pressure Contours All rights reserved by www.ijsrd.com 1933
C. Front Wing Assembly (6 PLATES OF NACA 4412): 1) Negative (-15 0 ) AOA : D. REAR WING ASSEMBLY (2 PLATES OF NACA 2408) 1) Negative (-15 0 ) AOA : Fig. 31: Velocity Contours Fig. 35: Velocity Contours Fig. 32: Pressure Contours 2) Zero (0 0 ) AOA : Fig. 36: Pressure Contours 2) Zero (0 0 ) AOA : Fig. 33: Velocity Contours Fig. 37: Velocity Contours Fig. 34: Pressure Contours Fig. 38: Pressure Contours All rights reserved by www.ijsrd.com 1934
IV. CONCLUSIONS A. Front Wing Airfoil V/S Rear Wing Airfoil: B. Front Wing Assembly V/S Rear Wing Assembly: C. Front Wing Airfoil V/S Front Wing Assembly: D. Rear Wing Airfoil V/S Rear Wing Assembly: E. Main Conclusions: 1) The approximate top speed as read from the analysis is 330 kmph A definite race to the finish! 2) Aerodynamics plays an integrated and essential role in the racing world. 3) Such a CFD testing helps to achieve great results along with an appreciable saving in costs. Note : Table 1: Front Airfoil (NACA 4412) v/s Rear Airfoil (NACA V. FUTURE PLANS Structural Analysis of Front wing airfoil NACA 4412 for calculation of Downforce. Structural Analysis of Rear wing airfoil NACA 2408 for calculation of Downforce. Structural Analysis of Front Wing Assembly for calculation of Downforce. Structural Analysis of Rear Wing Assembly for calculation of Downforce. Structural Analysis of the entire car model for calculation of Downforce. All rights reserved by www.ijsrd.com 1935
[Validations will be based on Zero AOA results] ACKNOWLEDGEMENT It is always a pleasure to remind the fine people who helped me throughout my project. I am extremely thankful to Dr. Dipali Thakkar for giving me an opportunity to undertake this project. I would like to give a special thanks and express my deep sense of gratitude to Mr. Arpit Patel for his assistance, expert guidance, and suggestions throughout this project work. Without the help of their knowledge and expertise in every facet of the study, from helping to find the relevant data and in analyzing the results, this project would not have been completed. I sincerely thank all other faculty members of the Aeronautical Department for helping me in all possible ways for the betterment of my project. Last, but certainly not the least, I am very thankful to my family and friends who have been giving me unconditional support throughout the entire period of my project, because without them, none of this would have been possible. REFERENCES [1] Triya Nanalal Vadgama, Mr. Arpit Patel, Dr. Dipali Thakkar, Design of Formula One Racing Car, International Journal of Engineering Research & Technology (ISSN: 2278-0181), Volume 4, Issue 04, pp. 702-712, April 2015 [2] A rear spoiler with adjustable aerodynamic profiles for a high performance road vehicle (WIPO; Patent No.: EP2631160; Application No.: 13156647; Inventor: de Luca Marco; Applicant: Ferrari SPA) [3] Aerodynamics by L.J. Clancy [4] Computational Fluid Dynamics by J.D. Anderson [5] Formula One Technical Regulations FIA Standards [6] Fundamentals of Aerodynamics by J.D. Anderson [7] Numerical Investigation of Flow Transition for NACA-4412 airfoil using Computational Fluid Dynamics (ISSN: 2319-8753; International Journal of Innovative Research in Science, Engineering and Technology - Vol. 2, Issue 7, July 2013) [8] Race Car Aerodynamics by Joseph Katz [9] Study of Front-Body of Formula One Car for Aerodynamics using CFD (ISSN: 2319-4847; International Journal of Application or Innovation in Engineering & Management (IJAIEM) - Volume 3, Issue 3, March 2014). All rights reserved by www.ijsrd.com 1936