design and simulation on the air dam for proton persona by using ...

SUPERVISOR DECLARATIONWe hereby declare that we have read this thesis <strong>and</strong> in our opinion this thesis issufficient in terms of scope <strong>and</strong> quality for the award of the degree of Bachelor ofMechanical Engineering.Signature :....................................................Supervisor : GAN LEONG MINGPosition: LECTURERDate:…………………………………Signature :....................................................Panel: MOHD YUSOF BIN TAIBPosition: LECTURERDate :....................................................

ÏØ ´½½µ¸ ´½¿µ Ò ´½µ¸ Ø ÐØ Ò × Ó ´µ × ÖÐÝ ÓÑÔÙØÄ ´¾µ ½ÆÕÙØÒ ´½µ Ò ´½µ ØÖÑÒ×È ´ · · µ ½Æ¿ ´ · µ ¾ ´½µ ´ µ ¾ ½ Æ ´½µ¾´ · µÈÖÓÒ Ò ×ÑÐÖ ×ÓÒ ÛØ ´µ Ð× ØÓ Ø ÜÔÐØ ÓÖÑ Ó ´¿µ º ÓÖ ÜÑÔи ÓÖ Æ ¿Û Ú ´¿µ ½¾¿ ÜÔ´ ½ · ¾ · ¿ µ ½¾¿ ÜÔ ´ ½ · ¾ · ¿ µÜ ´ ½ · ¾ · ¿ µØ ·´Æ ½ · Æ ¾ · Æ ¿ µ℄ ´½µÛØ ½¾¿ ½¾ ½¿ ¾¿ ´ ½ ¾ µ ¾ ´ ½ ¿ µ ¾ ´ ¾ ¿ µ ¾´ ½ · ¾ µ ¾ ´ ½ · ¿ µ ¾ ´ ¾ · ¿ µ ¾ ´½µÆÓØ ØØ ´¿µ × ÒÓ ØÖÑ× Ò ¾ ÛØ ½Æ ÓÖ Æ ¿ ÓÒ Ò Ð×Ó ×ÓÛØØ ´Òµ ¼ ÓÖ Ò¿ Ò ØÖÓÖ Ø ÜÔÒ×ÓÒ Ò ´µ ØÖÙÒØ× ½·ÜÔ ½·ÜÔ ¾·ÜÔ ¿ ´¾¼µ· ½¾ ÜÔ´ ½· ¾ µ· ½¿ ÜÔ´ ½· ¿ µ· ¾¿ ÜÔ´ ¾· ¿ µ ´¾½µ· ½¾¿ ÜÔ´ ½· ¾· ¿ µÛØ ¯ ½º ÍÔÓÒ ×Ù×ØØÙØÓÒ Ó ´¾¼µ ÒØÓ ´¾µ Ø ÛÐйÒÓÛÒ ØÖ ×ÓÐØÓÒ ×ÓÐÙØÓÒ Ó Ø ÃÎÕÙØÓÒ ÓÐÐÓÛ׺ Ì Æ¹×ÓÐØÓÒ ×ÓÐÙØÓÒ ÓÖ ÒÝ Æ ¿ Ò ÓÒ×ØÖÙØ Ò ×ÑÐÖ Ûݺ¿º ÜÑÔÐ Ì ×Ö ÕÙØÓÒ ÛØ ÓÒÚØÓÒÏ ÔÔÐÝ Ø ÑØÓ Ò ËØÓÒ ¾ ØÓ Ø ×Ö ÕÙØÓÒ ÛØ ÓÒÚØÓÒ ØÖÑ ¾℄¸Ù Ø · ÙÙ Ü Ù ÜÜ Ù´½ Ùµ ¼´¾¾µÛ ×Ö× Ø ÔÖÓÔØÓÒ Ó ÒÖÚ ÔÙÐ×׺ ÈÒÐÚ ÒÐÝ×× ´× ËØÓÒ µ ÖÚÐ× ØØÙ´Ü Øµ ¾ ÐÒ ´Ü ص ܾ ´Ü µ´¾¿µØÖÒ×ÓÖÑ× ´¾¾µ ÒØÓ Ø ÕÙÖØ ÕÙØÓÒÆ ´ µ ´ ÜÜÜ · Ü ÜØ µ· Ü´ Ø ÜÜ · ¾ ܵ¼´¾µ¿

iiSTUDENT DECLARATIONI declare that this thesis entitled Design <strong>and</strong> Simulation on the Air Dam for ProtonPersona by Using CFD Tool is the result of my own research except as cited inreferences. The thesis has not been accepted for any degree is not concurrentlysubmitted in c<strong>and</strong>idature for any other degree.Signature :………………………….Name : AHMAD SAPUAN BIN HASANDate : 10 NOVEMBER 2008

iiiDedicated to my belovedMother,Sisters,Brothers,Friends <strong>and</strong>My Father

ivACKNOWLEDGEMENTThis thesis is the end of my long journey in obtaining my degree inMechanical Engineering with Automotive. I have not travelled in a vacuum in thisjourney. There are some people who made this journey easier with words ofencouragement <strong>and</strong> more intellectually satisfying by offering different places to lookto exp<strong>and</strong> my theories <strong>and</strong> ideas. I would also like to gratefully acknowledge thesupport of some very special individuals. They helped me immensely by giving meencouragement <strong>and</strong> friendship.First a very special thanks you to Mr. Gan Leong Ming. Mr Gan Leong Minggave me the confidence <strong>and</strong> support to begin my degree in my Final Year Project.Mr. Gan challenged me to set my benchmark even higher <strong>and</strong> to look for solutions toproblems rather than focus on the problem. I learned to believe in my future my work<strong>and</strong> myself.Lastly but not least, my sincere gratitude to Mr. Mohd Fazli Bin Ismail <strong>and</strong>Mr. Faizul Bin Rajuli for their concern of my project progress <strong>and</strong> always be therewhen I need their helps. Also to other lecturers <strong>and</strong> technician who had directly <strong>and</strong>indirectly contributed in contributed in completing this project.

vABSTRACTThis project was carried out to <strong>design</strong> aerodynamic <strong>and</strong> efficient front air damfor Proton Persona car. In carrying this project, the objective is to compare the carstability for Proton Persona car with <strong>and</strong> without air dam. The whole process willinvolve <strong>design</strong>ing, matching, <strong>simulation</strong> approach <strong>and</strong> comparison the data. Airflowaround vehicle can affect many aspects of vehicle performance including vehicledrag, vehicle lift <strong>and</strong> down force. Vehicle lift <strong>and</strong> down force can affect the vehiclestability <strong>and</strong> h<strong>and</strong>ling. This air dam was <strong>design</strong> to reduce lift force <strong>and</strong> improve theturbulent air flow underneath Proton Persona car. The <strong>design</strong> is refer to the marketjournal <strong>and</strong> market also. The dimension gets from the model vehicle scanning by 3DScanner. Than sketch the base line of air dam in Solidwork. Besides that, prepare themodel vehicle in software environments for <strong>simulation</strong> process. This thesis focus on<strong>design</strong> of air dam <strong>and</strong> how it will affect to the underbody flow. The <strong>simulation</strong> iscomparing the vehicle model with <strong>and</strong> without air dam base pressure distribution.The result will be compare on pressure distribution underbody. The air dam willaffect the lift force on the front Proton Persona when moving in high speed.However, the height of air dam must suitable with road requirement to avoid damageto air dam when driving in rough road surface.

viABSTRAKProjek ini adalah bertujuan untuk mencorak penhadang udara yangaerodinamik dan cekap untuk kereta Proton Persona. Dalam menjayakan projek ini,objektifnya adalah memb<strong>and</strong>ingkan kestabilan untuk kereta Proton Persona denganmemasang penhadang udara dan tanpa penhadang udara. Keseluruhan proses akanmelibatkan reka bentuk penhadang udara, pasang, pendekatan simulasi danperb<strong>and</strong>ingan data. Aliran udara sekitar kenderaan boleh menjejaskan banyak aspekprestasi kenderaan termasuk seretan kenderaan, daya tujah ke atas pada bahagi<strong>and</strong>epan kenderaan dan daya kebawah. Daya angkat kenderaan dan daya kebawahboleh menjejaskan kestabilan kenderaan dan pem<strong>and</strong>uan. Penhadang udara ini adalahreka bentuk untuk mengurangkan daya angkat dan memperbaiki aliran udara yangtidak berpusar di bawah kereta Proton Persona. Reka bentuk ialah merujuk jurnaluntuk pasaran dan pasaran juga. Dimensi diperoleh daripada pengimbasan kenderaanoleh 3D Scanner. Selepas itu lakaran gambaran asas penhadang udara dilukis dalamSolidwork. Selain yang, menyediakan kenderaan misali dalam persekitaran perisianuntuk proses simulasi. Tumpuan tesis ini adalah kepada reka bentuk penhadangudara dan bagaimana ia akan menjejaskan untuk bawah kereta aliran. Simulasiadalah memb<strong>and</strong>ingkan kenderaan dengan penhadang dan tanpa penhadang udarataburan tekanan asas. Hasil akan menjadi perb<strong>and</strong>ingan di taburan tekanan bawahbadan. Empangan udara akan menjejaskan daya angkat di muka Proton Personaapabila masuk kelajuan tinggi. Bagaimanapun, ketinggian empangan udara perlusesuai dengan jalan keperluan bagi mengelakkan kerosakan untuk empangan udaraapabila mem<strong>and</strong>u di permukaan jalan yang tidak rata.

viiTABLE OF CONTENTPAGEDECLARATIONDEDICATIONACKNOWLEDGMENTABSTRACTABSTRAKLIST OF TABLELIST OF FIGURELIST OF SYMBOLLIST OF ABBREVIATIONLIST OF APPENDIXiiiiiivvvixxixiixiiixivCHAPTER 1INTRODUCTION1.1 Background Project 11.2 Problem Statement 21.3 Project Objective 31.4 Scope of Project 31.5 Flow Chart of the Project 4CHAPTER 2LITERATURE REVIEW2.0 Introduction 52.1 Vehicle Body Aerodynamic2.1.1 Venturi 72.1.2 Air Streamline 8

viii2.1.3 Drag Coefficient 92.1.4 Lift Coefficient 102.2 Aerodynamic Air Dam2.2.1 Underbody Dam 112.2.2 Stagnation Point at Air Dam 112.2.3 Corner Vane 122.2.4 Air Splitter 132.2.5 Percentage Difference 142.3 Design Characteristic2.3.1 Basic Design 152.3.2 Air Dam with Three Canards 162.3.3 Air Dam with Nozzle 17CHAPTER 3METHODOLOGY3.1 Project Methodology 183.2 First stages: Literature Study 203.3 Second Stage: Prepare 3D model of Proton Persona 203.3.1 Combine the Subgroup 223.3.2 Change to IGES File 233.4 Third Stage: Design <strong>and</strong> Assemble 233.4.1 Design Characteristic 253.5 Fourth Stage: Analyzing Using CFD Simulation 263.6 Fifth Stage: Analysis of Simulation Result 273.6.1 Valid the Result 28CHAPTER 4RESULT AND DISCUSSION4.1 Result 294.2 Comparison the Result With <strong>and</strong> Without Air Dam 304.2.1 Pressure Comparison 304.2.2 Summary of Pressure Comparison 324.2.3 Velocity Comparison 334.2.4 Summary of Pressure Comparison 35

ix4.2.5 Trajectories Pressure View 374.3 Data Collection 394.3.1 Summary of the Result 40CHAPTER 5CONCLUSION AND RECOMMENDATION5.1 Conclusion 435.2 Recommendation 44REFFERENCES 45Appendix A-J 47-56

xLIST OF TABLETABLE NO. TITLE PAGE3.1 Design Measurement 244.1 Result Pressure <strong>and</strong> Velocity for All Simulation 404.2 Summary of the result finding 41

xiLIST OF FIGURESFIGURE NO. TITLE PAGES2.1 Comparison of low <strong>and</strong> high aerodynamic drag forceswith rolling resistance 62.2 Air flows through the venturi 72.3 Streamline air flow around car 82.4 Pressure distribution above <strong>and</strong> below the body structure 92.5 Stagnation point flow 112.6 Influence of corner vanes in reducing truck side panelflow separation 122.7 Air Splitter affect to air flow 142.8 Basic <strong>design</strong> of air dam 152.9 Full Design Air Dam 162.10 Nozzle Shape in Both Side of Air Dam 173.1 Flow Chart of Methodology 193.2 Part of 3D Scanner 213.3 Ground clearance Proton Persona 243.4 the complete model assemble 243.5 Design 1 253.6 Design 2 263.7 Design 3 263.8 Condition Domain 274.1 Design 1 compare with model without air dam 31

xii4.2 Design 2 compare with model without air dam 324.3 Design 3 compare with model without air dam 324.4 Design 1 compare with model with air dam 344.5 Design 2 compare with without air dam model 354.6 Design 3 compare with model without air dam 354.7 Trajectories pressure <strong>design</strong> 1 374.8 Trajectories pressure <strong>design</strong> 2 374.9 Trajectories pressure <strong>design</strong> 3 384.10 The result point taken 39

xiiiLIST OF SYMBOLSF LLift force (N)ρ Density (kg/m 3 )V Velocity (ms -1 )A Area (m 3 )PPressure (Pa)P Atmosphere pressure (Pa @ atm)C DDrag coefficientF DDrag force (N)lLength (m)% Percentage

xvLIST OF APPENDIXAPPENDIX TITLE PAGEA Project Gantt chart 47B Grill 1 48C Grill 2 40D Design 1 50E Design 2 51F Design 3 52G Model Vehicle Proton Persona 53H Assemble 1 54I Assemble 2 55J Assemble 3 56

1CHAPTER 1INTRODUCTION1.0 Background of ProjectNow day, road vehicle tends to develop lift thrust on the body. Base on theProton Persona <strong>design</strong>, the upper aerodynamics shape will provide smooth to let airflow moving faster through the body. During high speed, pressure distribution atupper <strong>and</strong> underneath vehicle is different. The lift force occur when air pressure atunderneath is greater than upper air pressure. It does depend to the velocity of airflow surround the vehicle. According to Bernoulli principle, when increase velocitythe pressure will decrease <strong>and</strong> decrease velocity will increase pressure.This project will focus on study underneath air flow for Proton Persona. Anair dam was <strong>design</strong> to improve car performance by blocking air from to underneath<strong>and</strong> change the air direction around the body. With proper <strong>design</strong> air dam willgenerate negative down force to the vehicle body. The air dams create to fix liftthrust at the front Proton Persona <strong>and</strong> improve vehicle h<strong>and</strong>ling.

21.2 Problem StatementProton Persona is the most successful model in Malaysia produce by Proton.During moving in high speed, the vehicle tends to develop a partial vacuum on theupper contoured surface relative to underside pressure (Tsutomu, 1980). The air flowsplits up into the upper stream which move over the upper surface of the vehicle <strong>and</strong>the lower stream which moves below the bottom of the Proton Persona. The velocityof the stream upper <strong>and</strong> below the Proton Persona also difference. The result to thevehicle is having lift force or thrust upward. It will cause the front tire lose grip to theground <strong>and</strong> affect to stability of the vehicle. All of this will contribute to poor drivingperformance.An air dam was <strong>design</strong> to control the lift force at the front Proton Persona.However, there is many type of <strong>design</strong> in the market. This project will come out theair dam <strong>design</strong> that suitable for Proton Persona <strong>and</strong> improve the aerodynamic flow.1.3 Project ObjectivesBasically the main purpose in accomplishing this task are stated belowi. Design the aerodynamics front air dam for Proton Persona.ii. Simulation of aerodynamics for Proton Persona with <strong>and</strong> without air dam.

31.4 Scopes of ProjectThe scope of this project is focusing on the criteria that stated belowa. Literature study on the vehicle air flow system.b. 3D scanning of the existing Proton Persona.c. Design of air dam for Proton Persona.d. Boundary condition setting.e. Simulation of air flow for new <strong>design</strong> of air dam.f. Analysis on the <strong>simulation</strong> result.g. Report preparation.

41.5 Flow Chart of The ProjectSTARTLiterature Review3d Modeling of Studies VehicleConversion of 3d Car Model into SimulationEnvironmentConceptual Design of Front Air DamNoMatching WithVehicleYesBoundary Condition SettingAir Flow SimulationNoAnalysisYesFinal thesis documentationFinal presentationEnd

5CHAPTER 2LITERATURE REVIEW2.0 IntroductionThe importance of aerodynamics to race car has been known through most ofthe sport history. By the early 1960, the speed of race car increase rapidly. Base onone lap record speed for the Indianapolis 500 (United State) has been above 80mph(129kph) since before 1920. In an attempt to decrease speed <strong>and</strong>, therefore, increasesafety, regulations were enacted to limit engine power <strong>and</strong> tire size. Car <strong>design</strong>erswere forced to look elsewhere to give their team an advantage. The advantage wasfound in aerodynamics. [Cislunar Aerospace Inc, 1997].Air dam is creating to deal with aerodynamics. Air dam is a device made ofmetal or plastic fitted beneath the front bumper of an automobile <strong>and</strong> intended toenhance aerodynamics <strong>and</strong> stability by blocking the flow of turbulent air under thechassis refer to ‘The American Heritage® Dictionary of the English Language’:Fourth Edition 2000. Air dam also applies for heavy vehicle such as lorry <strong>and</strong> truckto improve fuel efficient (Doug, 2005).In the world modern car the manufacturers focus on the aerodynamicsperformance of the vehicle. The lift <strong>and</strong> drag forces that act on the vehicle giveimpact to performance <strong>and</strong> body shape. The manufacturers attempt to control theseforces to maximize the vehicle performance. The manufacturers also aware importantof air dam contribute on the aerodynamics performance. Some new models launchair dam integrated with the front bumper.

62.1 Vehicle Body AerodynamicsAerodynamics is the study of a solid body moving through the atmosphere<strong>and</strong> the interaction which takes place between the body surfaces <strong>and</strong> the surroundingair with varying relative speeds <strong>and</strong> wind directions (Heinz, 2002). Aerodynamicsdrag is usually neglected at low vehicle speed but the magnitude of air resistancebecomes important with the rising speed. This can be seen in Figure 2.1 belowwhich compares the aerodynamics drag forces of a weak streamlined <strong>and</strong> highlystreamlined for vehicle with difference velocity. A vehicle with high drag resistancetends to deceleration the vehicle. When increase the speed, the fuel consumptionefficiency is getting worst.Figure 2.1: Comparison of low <strong>and</strong> high aerodynamic drag forces with rollingResistance, (Heinz, 2002).

72.1.1 VenturiThe shape of surface also affects the aerodynamics drag. When air flowthrough a diverging <strong>and</strong> converging section of venturi the air pressure <strong>and</strong> speedchange show in Figure 2.2. Air molecules initially under atmospheric pressure, whenflow into small area the molecules are relatively close together. It will increase thepressure <strong>and</strong> minimum the speed of air flow. The velocity of air flow acceleratewhen move into the converging area to maintain the volume flow (Heinz, 2002). Atthe middle of venture it produces high velocity <strong>and</strong> low pressure because of the crosssection area at the middle. The exit presents diverging area, where air flowdecelerates because the molecules are able to move freely. For vehicle shape thefront presents diverging <strong>and</strong> converging at the rear.Figure 2.2: Air flows through the venturi (Heinz, 2002)