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DESIGN OF CAMBERED AEROFOIL FOR UNMANNED AERIAL

VEHICLE BASED ON SUBSONIC WIND TUNNEL TEST

By

Kh. Md. Faisal

Md. Faisal Kabir

Nahian Al Hossain Basunia

A Thesis

Submitted to the

Department of Aeronautical Engineering

In Partial Fulfillment of the

Requirements for the Degree

OfB.Sc. in Aeronautical Engineering

DEPARTMENT OF AERONAUTICAL ENGINEERING

MILITARY INSTITUTE OF SCIENCE AND TECHNOLOGY

MIRPUR CANTONMENT, DHAKA-1216, BANGLADESH

DECEMBER-2012


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Approved By:

Major Mahbubur Rahman Khan-Thesis Supervisor

Instructor, Class-B, Department of Aeronautical Engineering

Signature: _________________________________________


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Declaration

This thesis or any part of this thesis has not been submitted elsewhere for obtaining any degree.


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TABLE OF CONTENTS

List of Tables.................... VI

List of Figures... IX

List of symbols.. .. XV

Acknowledgement.. .............. XVII

Abstract... XVIII

1. Introduction.....11.1. Aerofoil Development 21.2. Historical Evolution................................ 5

2. Theory... 162.1. Aerofoil. 162.2. Aerofoil Design Characteristics 172.3. Types. 192.4. Aerofoil Terminology... 202.5. Aerodynamic Forces.212.6. Low-Speed Aerodynamics 222.7. Characterizing Aerofoil Performance... 23

3. Wind Tunnel Theory.253.1. Calibration of Wind Tunnel.. 253.2. Calibration of AFA3 balance 263.3. Drag Calibration273.4. Fore/Aft Calibration.. 283.5. Moment Calibration.. 29

4. Aerofoil Selection.304.1. Aerofoil Design Consideration. 304.2. Performance Requirement 33

5. Experimental Investigation... 355.1. Data for Aerofoil-1........................... 35


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5.2. Data for Aerofoil-2...535.3. Data for Aerofoil-3...71

6. Additional Investigation 906.1. Investigation of Cm- curves at different Reynolds Number.... 906.2. Investigation of Cd- curves at different Reynolds Number..... 966.3. Investigation of Cl- curves at different Reynolds Number... 1026.4. Investigation of Variation Maximum Lift Co-Efficient

With Maximum Camber of the 3 Aerofoils.... 108

6.5. Investigation of Variation Maximum Lift Co-EfficientWith Maximum Thickness of the 3 Aerofoils.... 113

6.6. Investigation of Variation Maximum Lift Co-EfficientWith Reynolds Number.. 118

6.7. Investigation of Cl Values At Different Angles of Attack.. 1216.8. Investigation of variation of Cl/Cd values at different Angles of Attack.... 123

7. Discussions & Recommendation.... 1297.1. Discussions..... 1297.2. Recommendations for future work..... 131

8. References........................... 1329. Bibliography... 133


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List of Tables

Table 5.1: Geometric Specification of Aerofoil-1.... 36

Table 5.2: Experimental Data for Aerofoil-1.... 36

Table 5.3: Experimental data for Aerofoil-1 at Re=200000..... 40

Table 5.4: Experimental data for Aerofoil-1 at Re=300000. 43

Table 5.5: Experimental data for Aerofoil-1 at Re=400000. 46

Table 5.6: Experimental data for Aerofoil-1 at Re=500000..... 49

Table 5.7: Performance Comparison of Aerofoil-1.. 52

Table 5.8: Geometric Specification of Aerofoil-2.... 54

Table 5.9: Experimental Data for Aerofoil-2 54

Table 5.10: Experimental data for Aerofoil-2 at Re=200000... 58




Table 5.14: Performance Comparison of Aerofoil-2.... 70

Table 5.15: Geometric Specification of Aerofoil-3.. 72

Table 5.16: Experimental Data for Aerofoil-3.. 73



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Table 5.21: Performance Comparison of Aerofoil-3.... 88

Table 6.1: Variation of Cmwith at: Re = 100000.. 90





Table 6.6: Variation of Cdwith at: Re = 100000... 96





Table 6.11: Variation of Clwith at: Re = 100000 102

Table 6.12: Variation of Clwith at: Re = 200000.... 103

Table 6.13: Variation of Clwith at: Re = 30000.. 104



Table 6.16: Variation of Cl max with camber at Re = 100000... 108


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Table 6.19: Variation of Cl max with camber at Re = 400000.. 111

Table 6.20: Variation of Cl max with camber at Re = 500000.. 112

Table 6.21: Variation of Cl max with maximum thickness at Re = 100000. 113

Table 6.22: Variation of Cl max with maximum thickness at Re = 200000..... 114




Table 6.26: Variation of Cl max with Reynolds Number of Aerofoil-1... 118

Table 6.27: Variation of Cl max with Reynolds Number of Aerofoil-2... 119

Table 6.28: Variation of Cl max with Reynolds Number of Aerofoil-3 120

Table 6.29: Variation of Cl values with Reynolds Number for the 3 Aerofoils at 7 AOA ... 121

Table 6.30: Variation of Cl values with Reynolds Number for the 3 Aerofoils at 5 AOA... 121

Table 6.31: Variation of Cl values with Reynolds Number for the 3 Aerofoils at 11 AOA..... 122

Table 6.32: variation of Cl/Cd values at different Angles of Attack at Re= 100000.. 123






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List of Figures

Fig 1.1: The earliest aerofoil design at last 19th century................................................................ 3

Fig 1.2: Aerofoil variation before World War II.............................................................................

4

Fig 2.1: Three Basic types of Aerofoils.... 19

Figure 2.2: Aerofoil geometry.. 20

Figure 2.3: Aerodynamic forces.... 22Fig 3.1: Drag Calibration.. 27

Fig 3.2: Fore/Aft Calibration.... 28

Fig 3.3: Moment Calibration..... 29

Fig 5.1: ClVs plot of Aerofoil-1 at Re=100000.... 37

Fig 5.2: Cd Vs for aerofoil 1 at Re=100000... 37

Fig 5.3: CmVs of Aerofoil-1 at Re=100000.. 38

Fig 5.4: L/D Vs for Aerofoil-1 at Re=100000... 38

Fig 5.5: Cl Vs Cd of Aerofoil-1 at Re=100000.. 39

Fig 5.6: ClVs plot of Aerofoil-1 at Re=200000.... 40

Fig 5.7: CdVs for aerofoil 1 at Re=200000... 40

Fig 5.8: CmVs of Aerofoil-1 at Re=200000.. 41

Fig 5.9: L/D Vs for aerofoil 1 at Re=200000 41


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Fig 5.10: Cl Vs Cd of Aerofoil-1 at Re=200000... 42

Fig 5.11: ClVs plot of Aerofoil-1 at Re=300000.. 43

Fig 5.12: CdVs for Aerofoil 1 at Re=300000.... 43

Fig 5.13: L/D Vs for Aerofoil 1 at Re=300000..... 44

Fig 5.14: CmVs of Aerofoil-1 at Re=300000.... 44

Fig 5.15: Cl Vs Cd of Aerofoil-1 at Re=300000.... 45


Fig 5.17: CdVs foraerofoil-1 at Re=400000 46


Fig 5.19: L/D Vs for aerofoil-1 at Re=400000.. 47

Fig 5.20: Cl Vs Cd of Aerofoil-1 at Re=400000 48


Fid 5.22: CdVs forAerofoil-1 at Re=500000.... 49

Fig 5.23: CmVs ofAerofoil-1 at Re=500000.... 50

Fig 5.24: L/D Vs for aerofoil 1 at Re=500000.. 50


Fig 5.26: Cl Vs plot of Aerofoil-2 at Re=100000.. 55

Fig 5.27: CdVs for aerofoil 2 at Re=100000.... 55

Fig 5.28: CmVs of Aerofoil-2 at Re=100000... 56

Fig 5.29: L/D Vs for Aerofoil-2 at Re=100000..... 56


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Fig 5.32: CdVs for aerofoil 2 at Re=200000..... 58





Fig 5.37: CdVs for Aerofoil 2 at Re=300000.... 61


Fig 5.39: L/D Vs for Aerofoil 2 at Re=300000..... 62

Fig 5.40: Cl Vs Cd of Aerofoil-2 at Re=300000 63

Fig 5.41: ClVs plot ofAerofoil-2 at Re=400000..... 64

Fig 5.42: CdVs foraerofoil-2 at Re=400000.... 64


Fig 5.44: Cl/Cd Vs for aerofoil-2 at Re=400000.... 65



Fig 5.47: CdVs forAerofoil-2 at Re=500000... 67

Fig 5.48: CmVs of Aerofoil-2 at Re=500000 68



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Fig 5.54: Cl/CdVs for aerofoil 3 at Re=100000.... 75

Fig 5.55: CdVs for aerofoil 3 at Re=100000. 75







Fig 5.62: CdVs for aerofoil 3 at Re=300000. 80







Fig 5.69: Cl/CdVs for aerofoil 3 at Re=400000 84


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Fig 5.72: CdVs foraerofoil 3 at Re=500000..... 86

Fig 5.73: Cm Vs ofAerofoil-3 at Re=500000.... 87

Fig 5.74: Cl/CdVs for aerofoil 3 at Re=500000 87


Fig 6.1: Graphical plot of variation of Cmwith at: Re = 100000.. 91





Fig 6.6: Graphical plot of variation of Cdwith at: Re = 100000... 97



Fig 6.9: Graphical plot of variation of Cdwith at: Re = 400000. 100


Fig 6.11: Graphical plot of variation of C lwith at: Re = 100000 103

Fig 6.12: Graphical plot of variation of C lwith at: Re = 200000.... 104




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Fig 6.15: Graphical plot of variation of C lwith at: Re = 500000 107

Fig 6.16: Graphical plot of variation of C lmax with camber at Re = 100000...... 108



Fig 6.19: Graphical plot of variation of C l max with camber at Re = 400000.. 111

Fig 6.20: Graphical plot of variation of C l max with camber at Re = 500000...... 112

Fig 6.21: Graphical plot of variation of C lmax with maximum thickness at Re = 100000. 113

Fig 6.22: Graphical plot of variation of C lmax with maximum thickness at Re = 200000..... 114



Fig 6.25: Graphical plot of variation of C l max with maximum thickness at Re = 500000.. 117

Fig 6.26: Graphical Plot of Variation of C l max with Reynolds Number of Aerofoil-1... 118



Figure 6.29: Graphical Plot of variation of C l/Cd values at different AOA at Re= 100000... 124

Figure 6.30: Graphical Plot of variation of Cl/Cd values at different AOA at Re= 200000... 125

Figure 6.31: Graphical Plot of variation of C l/Cdvalues at different AOA at Re= 300000126

Figure 6.32: Graphical Plot of variation of Cl/Cd values at different AOA at Re= 400000... 127

Figure 6.33: Graphical Plot of variation of Cl/Cd values at different AOA at Re= 500000128


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List of Symbols

Lift force

Drag force

M Pitching moment

Angle of attack

Free stream air density

Free stream dynamic pressure

Free stream velocity

Coefficient of lift

Coefficient of drag

Pitching moment coefficient

Normal force coefficient

Reynolds number

Specific fuel consumption

C chord

Dynamic viscosity

X (U) Distance along the upper surface of aerofoil in X axis

Y (U) Distance along the upper surface of aerofoil in Y axis


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X (L) Distance along the lower surface of aerofoil in X axis

Y (L) Distance along the upper surface of aerofoil in Y axis

A-1 Aerofoil-1

A-2 Aerofoil-2

A-3 Aerofoil-3

C max Maximum Camber

Cl max Maximum loft co-efficient

Tmax Maximum thickness


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ACKNOWLEDGEMENT

It gives us much pleasure to recall with cordial reverence and deepest of gratitude the

indispensable, constant encouragement and unparallel stimulation that influenced untiring

efforts. Knowledgeable advice and valuable suggestions of our respectable thesis advisor Major

Mahbub Sirbenefited us highly throughout the progress of this study. It could have been

impossible on our part to conduct this thesis and project without the effective guidance of his

methodological direction at each stage from the selection of the entire tropic to the writing down

the project.

Thanks to almighty Allah for making things and situation congenial and favourable for us to

complete the task. We are grateful to many individuals for the completion of the undergraduate

project and thesis program and report successfully. Military Institute of science & Technology

(MIST) provided necessary funding, enormous support and guidance for our undergraduate

project and thesis program.

At last warm wishes and thanks to our project members without whose continuous support it was

impossible to build up this project. The project really needed that friendly co-operation.


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ABSTRACT

Aerofoils have become an integral aspect of human flight as it has evolved over the last

century. As the design of each aerofoil determines many aspects of its use in the real world,

all significant characteristics must be analyzed prior to implementation. The aerodynamic

effects of pressure, drag, lift, and pitching moment were used to evaluate the behaviour of

the cambered aerofoils. In this experiment design of cambered aerofoil is done to make an UAV

on trial and error basis. With the help of a subsonic wind tunnel lift, drag, pitching moment and

other necessary data were then recorded to analyze and evaluate cambered aerofoils and to find

the most suitable one to meet our purpose.

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