saebrazilaerodesign-finalreport-fall2010

7/30/2019 SAEBrazilAeroDesign-FinalReport-Fall2010

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EML 4905 Senior Design Project

A SENIOR DESIGN PROJECT

PREPARED IN PARTIAL FULFILLMENT OF THE

REQUIREMENT FOR THE DEGREE OF

BACHELOR OF SCIENCE

IN

MECHANICAL ENGINEERING

SAE BRAZIL AERODESIGN CHALLENGE

Final Report

Miguel Jimenez

Ricardo Andres Lugo

Carlos Daniel Rojas

Advisors:

Andres Tremante, Ph. D.

George S. Dulikravich, Ph. D.

1 December 2010

This report is written in partial fulfillment of the requirements in EML 4905.

The contents represent the opinion of the authors and not the Department

of Mechanical and Materials Engineering.


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Table of Contents

Ethics Statement and Signatures ................................................................................. v

Acknowledgments ..................................................................................................... vi

List of Figures ............................................................................................................ vii

List of Tables .............................................................................................................. xi

Abstract .................................................................................................................... xii

1. Introduction ............................................................................................................ 1

1.1 Problem Statement...................................................................................................1

1.2. Motivation ..................................................................................................................2

1.3 Literature Survey ..........................................................................................................2

2. Project Formulation ................................................................................................ 6

2.1. Overview .....................................................................................................................6

2.2. Project Objectives ........................................................................................................6

2.3. Design Specifications, Constraints and Other Considerations ........................................6

3. Design Alternatives ............................................................................................... 14

3.1. Overview of Conceptual Designs Developed ............................................................... 143.1.1. Selection of Wings ..................................................................................................................... 15

3.1.2. Wing Design ............................................................................................................................... 173.1.3. Airfoil ......................................................................................................................................... 173.1.4. Fuselage ..................................................................................................................................... 173.1.5. Empennage ................................................................................................................................ 17

3.2. Design Alternative A .................................................................................................. 18

3.3. Design Alternative B .................................................................................................. 18

3.4. Design Alternative C .................................................................................................. 19

3.5. Feasibility Assessment ............................................................................................... 20

3.6. Proposed Design ........................................................................................................ 22

4. Project Management ............................................................................................. 23

4.1. Overview ................................................................................................................... 23

4.2. Breakdown of Work into Specific Tasks ...................................................................... 23

4.3. Organization of Work and Timeline ............................................................................ 24

4.4. Breakdown of Responsibilities among Team Members ............................................... 24

4.5. Total Hours Spent on Project ...................................................................................... 25


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4.6 Commercialization of Product ..................................................................................... 27

5. Aerodynamic Design and Analysis ......................................................................... 28

5.1. Introduction .............................................................................................................. 28

5.2. Main Wing Initial Design Parameters .......................................................................... 285.2.1. Introduction ............................................................................................................................... 285.2.2. Estimate of Take-Off Weight ..................................................................................................... 295.2.3. Wing Loading Selection .............................................................................................................. 29

5.3. Wing Design .............................................................................................................. 315.3.1. Airfoil Type ................................................................................................................................. 315.3.2. Taper Ratio ................................................................................................................................. 365.3.3. Sweep Angle .............................................................................................................................. 375.3.4. Dihedral Angle ........................................................................................................................... 375.3.5. Geometric Twist (Washout) ....................................................................................................... 375.3.6. Location ..................................................................................................................................... 385.3.7. Winglets ..................................................................................................................................... 38

5.4. Empennage Design .................................................................................................... 395.4.1. Location ..................................................................................................................................... 405.4.2. Horizontal Stabilizer ................................................................................................................... 405.4.3. Vertical Stabilizer ....................................................................................................................... 41

5.5. Aerodynamic Analysis ................................................................................................ 435.5.1. Theoretical Background ............................................................................................................. 435.5.2. Computational Fluid Dynamics (CFD) ........................................................................................ 48

5.6. Propeller Selection ..................................................................................................... 56

6. Structural Design and Analysis ............................................................................... 57

6.1. Wings ........................................................................................................................ 57

6.2. Fuselage .................................................................................................................... 616.2.1. Nose Section .............................................................................................................................. 616.2.3. Middle Section ........................................................................................................................... 636.2.4. Payload Bay ................................................................................................................................ 676.2.5. Cage ........................................................................................................................................... 686.2.6. Boom .......................................................................................................................................... 706.2.7. Fuselage Assembly ..................................................................................................................... 71

6.3. Empennage ............................................................................................................... 726.3.1. Horizontal Stabilizer ................................................................................................................... 726.3.2. Vertical Stabilizer ....................................................................................................................... 736.3.4. Empennage Assembly ................................................................................................................ 74

6.4. Landing Gear Structural Design .................................................................................. 75

6.5. Aircraft Structural Design Assembly ........................................................................... 77

6.4. Stability and Control Analysis ..................................................................................... 786.4.1. Introduction ............................................................................................................................... 786.4.2. Static Stability and Control........................................................................................................ 79 6.4.3. Sizing of Control Surfaces .......................................................................................................... 81

6.5. Electrical Design Layout ............................................................................................. 83


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7. Prototype Construction ......................................................................................... 85

7.1. Description of Prototype ............................................................................................ 85

7.2. Construction .............................................................................................................. 867.2.1. Wings ......................................................................................................................................... 86

7.2.2. Fuselage ..................................................................................................................................... 957.2.3. Empennage .............................................................................................................................. 102

7.3. Airplane Assembly ................................................................................................... 104

7.4. Monokote ............................................................................................................... 105

7.5. Parts List.................................................................................................................. 106

7.6. Prototype Cost Analysis ........................................................................................... 1077.6.1. Introduction ............................................................................................................................. 1077.6.2. Aircraft Construction ............................................................................................................... 1077.6.3. Competition Expenses ............................................................................................................. 1097.6.4. Travel Expenses ....................................................................................................................... 110

8. Testing and Evaluation ........................................................................................ 112

8.1. Overview ................................................................................................................. 112

8.2. Design of Experiments ............................................................................................. 112

8.3 Test Results and Data................................................................................................ 114

8.4 Evaluation of Experimental Results ........................................................................... 118

8.5. Improvement of the Design ...................................................................................... 118

9. Design Considerations ......................................................................................... 120

9.1. Assembly and Disassembly ...................................................................................... 120

9.2. Maintenance of the System ..................................................................................... 122

9.3. Environmental Impact .............................................................................................. 123

9.4. Risk Assessment ...................................................................................................... 124

10. Conclusion ........................................................................................................ 125

10.1. Conclusion and Discussion ...................................................................................... 125

10.2. Future Work .......................................................................................................... 125

11. References ........................................................................................................ 127

Appendices ............................................................................................................. 130Appendix A: Technical Drawings ..................................................................................... 130

Appendix A: Aircraft Assemblies ..................................................................................... 141

Appendix B: Detailed Raw Design Calculations and Analysis ............................................ 147

Appendix C: Catalogs and Manuals of Purchased Components ........................................ 166


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Ethics Statement and Signatures

The work submitted in this project is solely prepared by a team consisting of Miguel

Jimenez, Ricardo Lugo, and Carlos Rojas and it is original. Excerpts from others work have been

clearly identified, their work acknowledged within the text and listed in the list of references. All

of the engineering drawings, computer programs, formulations, design work, prototype

development and testing reported in this document are also original and prepared by the same

team of students.

Miguel Jimenez

Team Member

Ricardo A. Lugo

Team Member

Carlos D. Rojas

Team Member

Dr. Andres Tremante

Faculty Advisor


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Acknowledgments

The team would like to thank the following people for their selfless commitment to our

project and their constant support and dedication throughout these months, without them, this

would not be possible.

Mr. Stephen Wood

Prof. Javier Palencia Cuenca

Prof. Andres Tremante

Prof. George S. Dulikravich

Mr. Rick Zicarelli

Mr. Felipe Pradilla

Our families

FIU College of Engineering and Computing

The ME Department Professors and Staff

The Maintenance Staff in the EC building

WURN 1020 AM Radio Station

American Airlines

Andre Carpucci, SAE Brazil Pilot

Diego, and the Technological Institute of Aeronautics (ITA) Open Class Winning Team,

Leviata.

Rodrigo and his team, Keep Flying from the Polytechnic School of the University of Sao

Paulo.

Team 1 Senior Design Team

MAIDROC Laboratory Staff

All other contributing colleagues and friends not mentioned in this brief list.


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List of Figures

FIGURE 1: FLIGHT PATH FOR COMPETITION .................................................................................................. 1

FIGURE 2: AIRPLANE DIMENSIONS ................................................................................................................ 2

FIGURE 3: FIRST HOT AIR BALLOON ............................................................................................................... 3

FIGURE 4: WRIGHT FLYER IN 1903 .................................................................................................................. 3

FIGURE 5: APOLLO 11 ..................................................................................................................................... 4

FIGURE 6: 2.4 GHZ FUTABA RADIO TRANSMITTER ......................................................................................... 7

FIGURE 7: VOLTWATCH .................................................................................................................................. 7

FIGURE 8: O.S. .61 FX ENGINE ........................................................................................................................ 8

FIGURE 9: VALID AND INVALID TAKE-OFF ...................................................................................................... 9

FIGURE 10: FLIGHT PATH DEPENDING ON TAKE OFF SECTOR ........................................................................ 9

FIGURE 11: PAYLOAD BEING WEIGHED - SECOND ROUND .......................................................................... 10FIGURE 12: AIRPLANE BEING WEIGHED ....................................................................................................... 10

FIGURE 13: DIMENSIONAL INSPECTION LAYOUT ......................................................................................... 11

FIGURE 14: AIRPLANE HEIGHT INSPECTION ................................................................................................. 12

FIGURE 15: LENGTH MEASURING ................................................................................................................. 12

FIGURE 16: WIDTH MEASUREMENT ............................................................................................................. 13

FIGURE 17: FORCES OF AERONAUTICS ......................................................................................................... 14

FIGURE 18: SHAPE OF STRAIGHT WINGS ...................................................................................................... 15

FIGURE 19: WING PLACEMENT ..................................................................................................................... 16

FIGURE 20: DIHEDRAL ANGLE TYPES ............................................................................................................ 16

FIGURE 21: PARTS OF AN AIRFOIL ................................................................................................................ 17

FIGURE 22: PROPOSED DESIGN A ................................................................................................................. 18

FIGURE 23: PROPOSED DESIGN B ................................................................................................................. 19

FIGURE 24: PROPOSED DESIGN C ................................................................................................................. 19

FIGURE 25: PROPOSED DESIGN .................................................................................................................... 22

FIGURE 26: TAKE-OFF VELOCITY VS. WING LOADING .................................................................................. 30

FIGURE 27: XFOIL SCREENSHOT ................................................................................................................... 32

FIGURE 28: PROFILI PRO SOFTWARE ............................................................................................................ 33

FIGURE 29: CH10 .......................................................................................................................................... 34

FIGURE 30: FX 63-137 ................................................................................................................................... 34

FIGURE 31: EPPLER E420 .............................................................................................................................. 34

FIGURE 32: CL VS. ANGLE OF ATTACK AND CD VS. ANGLE OF ATTACK FOR CANDIDATE AIRFOILS ............. 35

FIGURE 33: L/D VS. ANGLE OF ATTACK AND CM VS. ALPHA FOR CANDIDATE AIRFOILS .............................. 36


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FIGURE 34: SWEEP ANGLE GEOMETRY ........................................................................................................ 37

FIGURE 35: IDEAL STALL PROGRESSION ....................................................................................................... 38

FIGURE 36: FIRST WINGLET PROTOTYPE ...................................................................................................... 39

FIGURE 37: EXPERIMENTAL WINGLET .......................................................................................................... 39

FIGURE 38: RECOMMENDED LOCATION FOR HORIZONTAL TAIL ................................................................. 40

FIGURE 39: NACA 0010 ................................................................................................................................. 41

FIGURE 40: EPPLER EA 6(-1)012 ................................................................................................................... 41

FIGURE 41: FOUR MAIN FORCES ON AIRCRAFT............................................................................................ 47

FIGURE 42: OPENFOAM PRESSURE DISTRIBUTION ALONG WING WITH VELOCITY STREAMLINES.............. 48

FIGURE 43: CROSS SECTIONAL VIEW OF THE PRESSURE DISTRIBUTION AT MIDSPAN IN PARAVIEW ......... 50

FIGURE 44: THRESHOLD INDICATING LOW PRESSURE AREA........................................................................ 51

FIGURE 45: WINGTIP VORTICES GENERATED BY PRESSURE DIFFERENTIALS IN TIP. .................................... 52

FIGURE 46: FUSELAGE PROTOTYPES ............................................................................................................ 53FIGURE 47: PRESSURE DISTRIBUTION - PROTOTYPE I .................................................................................. 53

FIGURE 48: PRESSURE DISTRIBUTION - PROTOTYPE II ................................................................................. 54

FIGURE 49: PRESSURE DISTRIBUTION PROTOTYPE I.................................................................................. 54

FIGURE 50: VELOCITY DISTRIBUTION - PROTOTYPE II .................................................................................. 55

FIGURE 51: WING SECTIONS ......................................................................................................................... 57

FIGURE 52: WING'S FORCE DISTRIBUTION AND RESTRAINTS ...................................................................... 58

FIGURE 53: SPAR FACTOR OF SAFETY ........................................................................................................... 58

FIGURE 54: WINGS STRUCTURAL DESIGN ................................................................................................... 59

FIGURE 55: PHYSICAL APPEARANCE OF RIBS ................................................................................................ 59

FIGURE 56 LEADING EDGE PLACEMENT ON RIB ........................................................................................... 60

FIGURE 57: COMPONENTS DISTRIBUTION ON FUSELAGE ............................................................................ 61

FIGURE 58: NOSE FUSELAGE STRUCTURE..................................................................................................... 62

FIGURE 59: THRUST SERVO PLACEMENT ON NOSE SECTION ....................................................................... 62

FIGURE 60: AERODYNAMIC STRUCTURE PLACEMENT AND GEOMETRICAL CHARACTERISTICS ................... 63

FIGURE 61: STRUCTURAL DESIGN OF MIDDLE SECTION OF FUSELAGE AND COMPONENTS ....................... 63

FIGURE 62: STATIC ANALYSIS BREAKDOWN ................................................................................................. 64

FIGURE 63: ASSEMBLY OF FRONT AND MIDDLE SECTION OF FUSELAGE ..................................................... 66

FIGURE 64: PAYLOAD ASSEMBLY .................................................................................................................. 67

FIGURE 65: CAGE STRUCTURE ...................................................................................................................... 68

FIGURE 66: FORCES AND RESTRAINTS IN STATIC ANALYSIS ......................................................................... 69

FIGURE 67: CAGE FACTOR OF SAFETY .......................................................................................................... 70

FIGURE 68: BOOM STRUCTURE .................................................................................................................... 71


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FIGURE 69: SERVO PLACEMENT AND LINK ................................................................................................... 71

FIGURE 70: FUSELAGE ASSEMBLY ................................................................................................................ 72

FIGURE 71: STRUCTURAL DESIGN OF HORIZONTAL STABILIZER .................................................................. 72

FIGURE 72: PLACEMENT OF HOLDING STRUCTURE AND PHYSICAL CHARACTERISTICS ............................... 73

FIGURE 73: STRUCTURAL DESIGN OF VERTICAL STABILIZER ........................................................................ 74

FIGURE 74: EMPENNAGE ASSEMBLY ............................................................................................................ 74

FIGURE 75: FACTOR OF SAFETY FOR LANDING GEAR ................................................................................... 75

FIGURE 76: STRESS ANALYSIS ON LANDING GEAR ....................................................................................... 76

FIGURE 77: STRUCTURAL DESIGN ASSEMBLY ............................................................................................... 77

FIGURE 78: LOCATION OF RUDDERS ............................................................................................................ 78

FIGURE 79: LOCATION OF ELEVATORS ......................................................................................................... 78

FIGURE 80: LOCATION OF AILERON ............................................................................................................. 79

FIGURE 81: BODY AXES AND SIGN CONVENTION OF THE AIRCRAFT ........................................................... 79FIGURE 82: HISTORICAL GUIDELINES ON AILERON SIZES ............................................................................. 81

FIGURE 83: AILERON SIZE ............................................................................................................................. 82

FIGURE 84: TAPERED CONTROL SURFACE .................................................................................................... 82

FIGURE 85: ELECTRICAL CIRCUIT LAYOUT FOR THE AIRPLANE ..................................................................... 83

FIGURE 86: VOLTAGE DISCHARGE DIAGRAM ............................................................................................... 84

FIGURE 87: FUTABA 4-CHANNEL TRANSMITTER .......................................................................................... 84

FIGURE 88: FINAL PROTOTYPE ..................................................................................................................... 85

FIGURE 89: WOOD ROUTER BIT ................................................................................................................... 87

FIGURE 90: CNC ANILAM MILL MACHINE ..................................................................................................... 87

FIGURE 91: RIBS MILLING PROCESS .............................................................................................................. 88

FIGURE 92: SKETCH OF RIBS ......................................................................................................................... 88

FIGURE 93: BALSA RIBS ................................................................................................................................. 89

FIGURE 94: WING JOINTS ............................................................................................................................. 90

FIGURE 95: WING JOINT ASSEMBLY ............................................................................................................. 90

FIGURE 96: WING ASSEMBLY ....................................................................................................................... 91

FIGURE 97: WINGLETS .................................................................................................................................. 92

FIGURE 98: HINGE ........................................................................................................................................ 92

FIGURE 99: CONTROL SURFACES OF WING .................................................................................................. 93

FIGURE 100: SERVO PLACEMENT ON THE WINGS ........................................................................................ 93

FIGURE 101: COMPLETE WING ASSEMBLY ................................................................................................... 94

FIGURE 102: CONSTRUCTION OF FUSELAGE ................................................................................................ 95

FIGURE 103: FUSELAGE STRUCTURE ............................................................................................................ 96


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FIGURE 104: COMPONENTS ON FUSELAGE .................................................................................................. 96

FIGURE 105 ALUMINUM'S RODS .................................................................................................................. 97

FIGURE 106 FINAL CAGE STRUCTURE ........................................................................................................... 97

FIGURE 107 FUSELAGE-CAGE JOINT. ............................................................................................................ 98

FIGURE 108: LOADING DOOR ....................................................................................................................... 98

FIGURE 109: SCREWS UTILIZED ON WING-CAGE JOINT ............................................................................... 99

FIGURE 110: WINGS-CAGE JOINT I ............................................................................................................... 99

FIGURE 111: CLAMP ................................................................................................................................... 100

FIGURE 112: WINGS-CAGE FINAL ASSEMBLY ............................................................................................. 100

FIGURE 113: BOOM-CAGE JOINT ................................................................................................................ 101

FIGURE 114: SERVO PLACEMENT AND HOLDING STRUCTURE IN BOOM SECTION .................................... 101

FIGURE 115: REAL-SCALE DRAWING FOR EMPENNAGE ............................................................................. 102

FIGURE 116: HORIZONTAL STABILIZER WITH BOOM-EMPENNAGE JOINT ................................................. 103FIGURE 117 EMPENNAGE ASSEMBLY ......................................................................................................... 103

FIGURE 118: CONTROL SURFACES ON EMPENNAGE .................................................................................. 104

FIGURE 119: AIRCRAFT ASSEMBLY ............................................................................................................. 104

FIGURE 120 MONOKOTE ............................................................................................................................ 105

FIGURE 121: VOLTWATCH .......................................................................................................................... 113

FIGURE 122: HANGING SCALE .................................................................................................................... 114

FIGURE 123: FUTABA S3003 SERVO ........................................................................................................... 115

FIGURE 124: FIRST TAKE-OFF ...................................................................................................................... 115

FIGURE 125: FIRST LANDING SEQUENCE .................................................................................................... 116

FIGURE 126: FIRST LANDING ROLL ............................................................................................................. 117

FIGURE 127: LANDING GEAR USED AT THE COMPETITION ........................................................................ 119

FIGURE 128: ASSEMBLY PROCESS............................................................................................................... 121

FIGURE 129: PAYLOAD BAY ........................................................................................................................ 121

FIGURE 130 COMPLETE ASSEMBLY OF AIRCRAFT ...................................................................................... 122


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List of Tables

TABLE 1: DESIGN ALTERNATIVE OPTIONS .................................................................................................... 15

TABLE 2: PROPOSED DESIGN A CONFIGURATION ........................................................................................ 18

TABLE 3: PROPOSED DESIGN B CONFIGURATION ........................................................................................ 18

TABLE 4: PROPOSED DESIGN C CONFIGURATION ........................................................................................ 19

TABLE 5: COMPARISON BETWEEN DIFFERENT DESIGN ALTERNATIVES ....................................................... 20

TABLE 6: PROPOSED DESIGN CONFIGURATION ........................................................................................... 22

TABLE 7: ESTIMATED TAKE-OFF WEIGHT ESTIMATES .................................................................................. 29

TABLE 8: PRELIMINARY DIMENSIONING OF AIRPLANE ................................................................................ 31

TABLE 9: CHORD LENGTHS IN TIP ................................................................................................................. 37

TABLE 10: SIZE REDUCTION OPTIMIZATION ON VERTICAL STABILIZER ........................................................ 42

TABLE 11: INITIAL (GENERAL) CONDITIONS FOR CFD ANALYSIS .................................................................. 50TABLE 12: DIFFERENCE BETWEEN THEORETICAL 2D DATA AND 3D FINITE WINGS FOR ALPHA = 0 ............ 51

TABLE 13: AIRCRAFT'S LOAD STATIC ANALYSIS ............................................................................................ 64

TABLE 14: A36 STEEL PHYSICAL PROPERTIES ................................................................................................ 67

TABLE 15: 1060 ALUMINUM PHYSICAL PROPERTIES .................................................................................... 69

TABLE 16: PARTS LIST ................................................................................................................................ 106

TABLE 17: AIRCRAFT EXPENSES .................................................................................................................. 108

TABLE 18: COMPETITION EXPENSES .......................................................................................................... 109

TABLE 19: TRAVEL EXPENSES ..................................................................................................................... 110

TABLE 20: EXPERIMENT LAYOUT ................................................................................................................ 112

TABLE 21: PROPELLER TESTING AND SELECTION ....................................................................................... 114

TABLE 22: FLIGHT PARAMETERS FOR ROUND 1 ......................................................................................... 117

TABLE 23: FLIGHT DATA FOR ROUND 2 ...................................................................................................... 118

TABLE 24: LANDING GEAR IMPROVEMENT ................................................................................................ 119


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Abstract

SAE Brazil AeroDesign is a competition that gathers engineering students from different

parts of the world, with the objective of designing, constructing, and testing a Remote

Controlled (RC) aircraft that must be able to lift the maximum possible payload within the given

geometrical restraints and engine restrictions. After this competition conditions have been

assigned, it is understood that the specific mission of this airplane is that of a high-lift and short

take-off and landing (STOL) one, and low Reynolds number fluid dynamics methodology applies

when calculating aerodynamics of the craft.

The design process of the aircraft begins with important and extensive research analysis

on similar airplane types which performed related missions. Historical data is then adapted tothis scaled-down application, and after sizing down these values, preliminary estimates and

calculations are performed and later refined to achieve a competitive aerodynamic structure.

Furthermore, with the use of available software programs, important airfoil data is used to

design an optimal wing design, which, for the sake of this project, needs to maximize the lift-to-

drag ratio, better known as L/D.

After this preliminary design is obtained, theoretical values need to be tested through

the use of computational fluid dynamics software programs. With the use of a Tesla-128 clusterin the Multidisciplinary Analysis, Inverse Design, Robust Optimization and Control (MAIDROC)

Laboratory in the College of Engineering and Computing, a Linux-based open source program,

called OpenFOAM, is chosen for the aerodynamic studies that are performed on the main wing

and fuselage of the airplane. This software program poses no licensing limitations due to its

open source nature, allowing the designers to maximize the required number of nodes and

elements required by their simulation in order to obtain optimal results. After comparing these

results with theoretical values, a structure capable of shaping this aerodynamically optimized

airplane is then designed.

All the components of the aircraft where thoroughly modeled and designed with the use

of computer aided design (CAD) software, such as ANSYS and SolidWorks, in order to perform

the necessary structural analysis testing and finite element analysis (FEA) simulations. After the


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components are designed, the feasibility of manufacturing is then assessed. If all criteria are

met, and components have market availability and affordability, the construction process starts.

Cost is a very important factor in the development of the project, and it is always kept to

its minimum possible value. Total cost of the project includes expenses made on aircraft design

and construction, competition expenses and travel expenses.

The competition took place in Sao Jose dos Campos, Brazil, from October 21 st through

October 24th. The teams participation represented a milestone in our colleges international

participation in engineering competitions, and set a solid foundation for the participation of

other teams in the school in future events. Important media coverage, such as featuring in the

schools newspaper, The Beacon, and a radio interview in WURN 1020 AM, represented the

willingness and commitment this team had to compete abroad this past October. Two grants,

one by American Airlines and one by the College of Engineering, further proved the external

interest and confidence in the participation abroad.

In addition, final results on the aircrafts behavior during takeoff, landing, and during

flight time, as well as the competition outcomes are presented and discussed in the final

sections of the report. Theoretical estimates were compared to actual values, and satisfactory

results were obtained.

As a final point, it should be noted that the successful construction, testing and

participation of the team in Brazil is pioneering in every aspect, after careful research and

development stages which lasted over nine months. It is the teams belief thatthis is just the

beginning of many more projects that will make Florida International University a recognized

and respected school in these SAE events, and school support is crucial for the educational

development of these projects and endeavors.


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1. Introduction

1.1 Problem Statement

The AeroDesign competition is a collegiate design event hosted and created by the Society ofAutomotive Engineers (SAE), which is an organization that oversees the design, manufacturing and

maintenance of automobiles and self-propelled vehicles for use on land, sea and air. Such organization

conducts different types of competitions for engineering students. In such competitions; dedication,

creativity and engineering skills and knowledge of students are tested. One of the competitions that SAE

International organizes annually is the AeroDesign competition.

Three different AeroDesign competitions are organized; East and West series, which are located

in the United States, and AeroDesign Brazil, which is hosted by the national chapter of SAE in that

country. Due to the dates on which these competitions are held, the best option available for the team

to choose is AeroDesign Brazil. The competition was held in Sao Jose dos Campos, October 20 th through

the 24th of 2010. It should be noted that this city is Brazils aeronautical center, hosting the worlds third

airplane manufacturer, Embraer, as well as their Aerospace National Agency, the Centro Tecnologico

Aeroespacial(CTA).

This competition consists on the design and construction remote controlled (RC) aircraft capable

of lifting a maximum payload. There are three different classes in which groups competed in: Regular,

Open, and Micro. The PantherWings team, as it was christened, decided to go on the Regular Class for

being the best suited class given the specifications of each. The Open Class is restricted to veterans of

previous competitions, and Micro class is considered very risky due to unfavorable atmospheric

conditions that might arise on the day of the competition, therefore some past experience is also a

must.

After takeoff, the airplane is expected to complete a loop as shown inFigure 1.

Figure 1: Flight Path for Competition


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The length of the runway in which the airplane must take off by is 61 meters, while the length in

which it can land is 122 meters. A group is given an allotted time of three minutes to allow the plane to

take off. The engine that must be used is a O.S. .61 FX engine. The dimensions of the airplane are very

simple to understand, the sum of the total length, width and height of the aircraft must be greater than

or equal to 4.00 meters and less than or equal to 6.5 meters. Figure 2 shows a better representation of

the dimensions.

Figure 2: Airplane Dimensions

1.2. Motivation

The development of this project involves fundamentals of aeronautics, aerodynamics and fluid

dynamics. Calculations and formulas have to be made based on the goal of the competition, which is

maximum payload on an aircraft. Being able to design, construct and build an aircraft represented

plenty of challenges that have been overcome. Organization is critical in the development of this type of

project, and team work and leadership on each of the group members was indispensable.

Radio Control (R/C) models such as cars, trucks, boats, airplanes, and helicopters are a hobby

that has been around for a long time. This hobby involves knowledge in physics mechanics and some

electrical field knowledge. Students involved in mechanical engineering have a very solid background in

each of these areas, and having this type of background represents an enormous advantage in the

design and construction of a radio control airplane.

As students of Florida International University, it was highly motivating to represent Florida

International University in SAE Brazil AeroDesign 2010, which took place on October 20-24, 2010 in Sao

Jose dos Campos, Brazil.

1.3 Literature Survey

Aviation, in some form or another, dates back to about 200 B.C. in form of a kite. They were

used by the Chinese as a military advantage by calculating distances between different posts. The next

advancement in the aviation field didnt come until the late 18th century as a hot air balloon in France.


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The first flight of the hot air balloon lasted about 4 minutes and 35 seconds and reached a maximum

height of about 80 feet. Figure 3 shows an illustration of the first hot air balloon.

Figure 3: First Hot Air Balloon

The first sustained flight by a powered and controlled aircraft was obtained by the Wright

brothers, Orville and Wilbur, in North Carolina on December 17, 1903. The first flight lasted about 12

seconds and spanned about 120 feet. Figure 4 demonstrates the Wright Flyer while in flight in Kitty

Hawk, North Carolina.

Figure 4: Wright Flyer in 1903

During World War I, airplanes became a big advantage for countries when dealing in combat

situations, as well as for communication. Radiotelephones were being used on these straightforward


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aircrafts which assisted in communication between pilots and ground commanders. The first airplanes

with weapons and machine guns attached to them didnt appear until 1914. Soon after then, it became

common to see air to air combat and fighter planes.

Aviation began to be applied to other things such as commercial aviation and cargo after World

War II. In the 1950s and 1960s, all that was learned from airplanes, was being applied to something

more advanced; space travel. The Russians were the first to send satellites into space and orbit the

Earth, while the United States and NASA launched the first successful mission to the moon with Apollo

11 in 1969. Figure 5 shows Apollo 11 blasting off from Kennedy Space Center in Florida.

Figure 5: Apollo 11

Remote controlled airplanes have fascinated people and enthusiasts since about the 1930s.

Nowadays there are many groups, such as the AMA (Academy of Model Aeronautics) that hold meetings

and gatherings throughout the country, and where hobbyists can get together and talk and share

information about RC Airplanes. Many parks such as Tropical Park in Miami, FL, as well as Markham Park

in Weston, FL, host events where people can fly their own airplanes in a vast open space.

These remote controlled aircrafts come in different kits such as ready to fly, almost ready to fly,

balsa kits, and from scratch. These levels in kits mainly depend on the expertise the person has in this

field. People usually start off with ready to fly kits in which planes come pre-assembled, and work their

way towards less assembled planes and kits. Important parts in controlling an RC airplane are the

receivers and servos. Some of these include ailerons, elevator, throttle, and rudder which control the

roll, pitch, and yaw of an aircraft. Different frequencies are used to communicate to the airplane from

the remote control. In the United States, the frequency that is mostly used for toys and RC airplanes is

72 MHzs. More recently, it is very common to see hobbyists use the newest 2.4 GHzs frequency on


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their aircrafts and remote controls, mainly due to its ease of operation, which does not require the users

to report channels so that there is no conflict.


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2. Project Formulation

2.1. Overview

In order to be qualified to compete in the 2010 SAE Brazil AeroDesign, there were specific and

important restrictions and constraints that had to be abided by. The competition was split up into 3

classes: Regular, Micro, and Open. It was decided to compete in the Regular class since it fit the best

interests of the team. Each category had its own unique rules and regulations. These rules deal with, but

are not limited to, different parameters such as the size and dimensions of the aircraft, the weight of the

aircraft, and the specific engine that must be used. These guidelines helped create a level playing field at

the competition between all of the groups and made sure that no group had a competitive advantage

over another one through the expert advice of professionals, something that is both discouraged and

not allowed by the organizers.

2.2. Project Objectives

At the time it was decided to choose to design and construct a remote controlled airplane for

the AeroDesign competition, one of the goals was to fly the airplane successfully. Many colleagues that

were reached out to for advice and knowledge about this subject told us that it is very difficult to design

an airplane that would fly. Through lots of hard work and dedication, this goal, as well as achieving a

high result in the competition, would be within reach and attainable.

The SAE Brazil AeroDesign competition dates back to 2001 where 40 teams from all over Brazil

competed in the inaugural event. As the years went by, the competition began to expand in participants

and started to be acknowledged and recognized at both a national and international level. Teams from

Mexico, Venezuela, and India have been represented at this event. No team from the United States has

participated in the competition, and it was a great motivation the fact that the teams participation

would mark the first team to do so and to represent Florida International University at a high manner in

an international competition.

2.3. Design Specifications, Constraints and Other Considerations

SAE Brazil and its Competition Technical Committee clearly define the rules and regulations for

the competition in its Operational Procedures Handbook distributed to all participating teams and

available online for more convenient use. If deemed necessary by the committee, some modifications

are made in this handbook and it is important to follow the one of the corresponding year of the event.


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There are specific rules that all three classes must follow, as well as specific regulations for the different

categories.

The radio transmitter that is to be used at the competition is to be of 2.4 GHz. The Futaba

remote control of this frequency that will be used at this competition is shown below.

Figure 6: 2.4 GHz Futaba Radio Transmitter

New to regulations this year was the introduction of a VoltWatch Receiver Battery Monitor. This

will be used to verify the charge of the battery pack, in this case Nickel-metal hydride (NiMH). This was

implemented to make sure there was not a stop in connection between the transmitter and receiver

while in flight, thus causing the airplane to crash and not be able to finish its flight. The transmitter usedis shown in Figure 7 and is compatible with NiMH and NiCd batteries.

Figure 7: VoltWatch

Another type that could be used in the competition is Lithium Polymer (Li-Po) batteries. A few

advantages of using this kind battery are that it has a higher capacity and weighs less than the Nickel-

metal hydride and the Nickel Cadmium batteries. A few disadvantages included were that it has an

explosion risk because it requires a confined area to charge, it does not handle impact very well, and it is

highly flammable. A key factor in choosing an NiMH battery over a Li-Po battery was the lower price


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because of the limited budget. A Nickel-metal hydride battery pack ranges from $5 to $7, while the

Lithium-Polymer batteries range from $22-$27.

For the teams competing in the Regular Class, the specified engine that must be used is an O.S.

0.61 FX shown in Figure 8.

Figure 8: O.S. .61 FX Engine

This particular engine has a displacement of 0.61 cubic inches and a horsepower of 1.9 at 16,000

RPM; the RPMs range from 2,000 to 17,000. The total weight of the engine is 19.4 ounces

(approximately 0.55 kg) and its stroke is 0.866 inches. Another engine that could have been used was

the K&B 0.61 RC/ABC (PN 6170).

When the airplane has completed preliminary inspections, the competitions judges and

organizers fill up the gas tank with fuel and it is placed in line to go onto the runway. Once on the

runway, the main landing gear is aligned with a line marked on the landing strip. Each team is given 3

attempts to take, or 3 minutes, whichever comes first. There are two sectors in which the aircraft must

take off at; the first ending at 30.5 meters from the start and the second finishing at 61 meters from the

start. The aircraft must be off the ground before it reaches the end of Sector 2.


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Figure 9: Valid and Invalid Take-Off

The Figure 9 displays valid and invalid take off of the airplane. A judge is standing down the

runway and lined up with the end of Sector 2. If the judge observes that the airplane did not take off

within the defined distance, he or she will raise a red flag, therefore forfeiting that attempt. If the

aircraft takes off within Sector 1 it is given approximately 13 points per kilogram of weight. If the aircraft

takes off within Sector 2, it is given approximately 8 points per kilogram of weight.

Figure 10: Flight Path Depending on Take Off Sector

As shown in the previous figure, if a team is able to take off before the end of Sector 1, not only

will it be awarded more points towards the final classification, but it will have to complete a much

shorter circuit. Despite whichever sector a plane took off in, all aircrafts must land and come to a

complete stop within 122 meters.

After the removal of the payload, the payload and the airplane are weighed separately. Figure

11 show the process of the payload and airplane being weighed.


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Figure 11: Payload Being Weighed - Second Round

Figure 12: Airplane Being Weighed

Once, and if the airplane completes the correct flight path, and lands successfully, a few

inspections are conducted to make sure the aircraft is qualified and under the given dimensions.

Important items that will be used to inspect the airplanes are four distinctive rectangular shapes, a

height gauge, and a tape measure. During this process, the aircraft must be lying flat on the floor, and

then the rectangles will be adjusted to the level of the wings. To check the length, the spinner of the


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airplane must be touching one of these fixtures, then the rear most part of the aircraft should be in

contact with another fixture.

Figure 13: Dimensional Inspection Layout

Figure 14 depicts what occurs during a typical inspection of an airplane after its successful flight.

In order to find the height of the airplane, the highest point will be found with respect to a gauge arm

which is resting on the floor.


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Figure 14: Airplane Height Inspection

Demonstrated in Figure 14 is an example of how the height of the airplane is measured. Once

this data is collected, the sum of the length, height, and sum of the distance between the flight-

generating devices (wings) must be greater than or equal to 4 meters and less than or equal to 6.5

meters. The next figures are from the competition and how they measured the aircraft.

Figure 15: Length Measuring


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Figure 16: Width Measurement

It is important to note the payload bay must be reusable and used in every flight run. Cutting

tools, such as scissors and knives are prohibited to be used in the act of removing the payload from the

airplane. The payload bay should also not alter the dimensions of the airplane permanently.


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3. Design Alternatives

3.1. Overview of Conceptual Designs Developed

It was established that the design of a RC Airplane requires different types of approaches.

Placement of the wings, type of wing, dihedral angle, and geometry of the airfoil depend in the

performance and mission of the airplane. The main purpose of the airplane required for this

competition is to carry a maximum payload with a predefined engine. With this purpose in mind,

different designs were taken into consideration. Computer Aided Design (CAD) models of each of the

designs have been drawn, and differences between them are described.

There are four different forces that need to be considered when designing an airplane. These

four forces are thrust, lift, drag and weight. Figure 17 shows a graphical representation where these

forces are located.

Figure 17: Forces of Aeronautics

A Radio Controlled (RC) airplane is divided into parts or components: Wings, fuselage, power

plant, and landing gear.

From research presented in the previous section, alternative designs are to be presented and

compared. Design of the aircraft is divided into three main sections: Wings, fuselage and empennage.

Each of these components offers different prototypes and designs; meaning that combinations between

components is the path to be taken. Some important decisions were taken with respect to the design of

the aircraft. The geometry of wing to be tested is straight wing. There is no point in testing all the

different wings geometries knowing that straight wing is the configuration that offers more stability to

the aircraft with respect to the other configurations. Moreover, low wing configuration is not taken into

consideration, mainly due to the fact that advantages of low wing configurations are not related with

the specific purpose of aircraft, which is high stability. Only high and mid-wings are proposed in the

designs. From all the different empennage configurations, only the two assemblies that offer more

stability to the aircraft are taken into account. The two tail configurations to be proposed are standard

tail, and T-type tail. For this section, the fuselage is treated as a neutral component of the aircraft, and it


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is only utilized for illustrative purposes. Geometrical and physical characteristics of fuselage are

determined by using Computational Fluid Dynamics (CFD), which is discussed in the Aerodynamics

section of the report. Table 1 summarizes all different options available to determine the prototypes to

be analyzed.

Table 1: Design Alternative Options

Wing Placement Wings Geometry Empennage Configuration

High Wing Straight Standard Tail

Tapered

Medium Wing Tapered Dihedral T-Tail

From Table 1, a total of 12 different combinations are available. The three most efficient and

stable prototypes are proposed.

3.1.1. Selection of Wings

The main difference between mainstream RC airplanes is the shape of the wings. There are four

types of wing shapes in airplanes: Straight, swing, sweep, and delta. The reason why there are different

types of wings is because there are different functions that are considered when an airplane is designed,

and this involves different speed and altitude. The type of wing that has been chosen for the design of

this airplane is the straight wing. According to Anderson, the reason for this selection is because this

type of wing is designed for small airplanes that do not require high speeds, and also due to the physical

characteristics of the straight wing, lift is increased in low speeds. There are different shapes of straight

wings; such as rectangular, elliptical, and tapered.

Figure 18 illustrates the geometry of each of the different types of straight wings.

Figure 18: Shape of Straight Wings


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These different types of geometries are to be tested by CFD analysis in OpenFOAM. Each of the

geometries is compared to each other, and the most efficient geometry is chosen to the final prototype

design. Even though flaps and slats are essential during the takeoff and landing of a real airplane, these

two components will not be taken into consideration in the design of the wings because the speed that

the airplane is going to experience will not require these mechanisms. The regime of speed that the

airplane is going to undergo is subsonic, which means that the velocity will always be less than Mach 1.

Placement of the wings in the fuselage has an enormous effect on stability and maneuverability

of the airplane. There are three configurations regarding placement of the wings in RC airplanes: High,

low, and mid wing. High wings give more stability to the plane with respect with the other two

configurations, which is crucial in the design of this airplane. Low and mid wing airplanes have more

maneuverability but stability is decreased. Stability can be increase using dihedral angle. The final design

will be determined based on testing. Figure 19 illustrates the wings placement in an airplane.

Figure 19: Wing Placement

Dihedral angle is the angle between the outer tip of the wings, and the fixed part of the wing

attached in the fuselage of the airplane. There are three different types of dihedral angles: Straight, Tip,

and Polyhedral. Figure 20 shows graphically how these types of dihedral differ from each other.

Figure 20: Dihedral Angle Types

The decision for which dihedral is better truly comes from extensive fluid dynamics evaluation,

but for practical purposes, a polyhedral wing is very complicated to manufacture, since it will require


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two different angle sets. In light of this, a hybrid of tip dihedral and straight dihedral is considered, since

due to material availability, the carbon fiber rods will force to split the wings in three pieces, a

consideration also took for transportation purposes.

3.1.2. Wing Design

Depending on the geometry of the wing, lift is may be increased or decreased. Curved or

cambered airfoils create more lift than flat surfaces. That explains the shape that most of the airfoils

have. The method, in which geometry is studied, is with the airfoil of the wing. As computers and

technology have progressed at a remarkable pace in the last years, computational studies have been

more resembling of the always-reliable wind tunnel testing.. Nowadays, CFD studies in powerful

computers allows for visualization of pressure fields, velocity profiles, streamlines and many other

important characteristics that the airplane is going to experience during the time of flight.

Determination of the type of airfoil to be chosen depends on testing.

3.1.3. Airfoil

Selection of the airfoil is a critical part in the design of wings. Depending on the airfoils

geometrical characteristics, drag and lift can be reduced or increased. Figure 21 determines the principal

parts of an airfoil. Understanding each of the parts in an airfoil is crucial when deciding what type airfoil

is to be utilized in the airplane.

Figure 21: Parts of an Airfoil

3.1.4. Fuselage

The body of the airplane, or fuselage, is the main body structure of the aircraft. In this design,

the fuselage is going to enclose the engine. Some particular fuselages generate some lift, but

considering dimensions and speed of the RC airplane, this force is neglected for this application,

although optimization is to be performed to achieve minimal drag with maximal lift contribution.

3.1.5. Empennage

The tail of an airplane, or empennage, manages most of the stability and control of the aircraft.

The concept of flight dynamics plays an important role in the control and stability of the airplane. Flight


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Figure 23: Proposed Design B

Configuration of proposed design B offers stability with selected placement and geometry of the

wing. By using standard tail, stability of airplane is. Standard Tail configuration, as shown in Figure 23,

has the physical characteristic of having the vertical stabilizer mounted in top of the horizontal stabilizer.

It is very important to denote that construction of standard tail is not as complex as the T-Tail

construction. One of the main disadvantages of this prototype is the loss of control of pitch by not using

the T-Tail configuration, and the complexity of manufacturing tapered wings.

3.4. Design Alternative C

Proposed design C has the following configuration:

Table 4: Proposed Design C Configuration

Wing Placement Wing Geometry Empennage Configuration

Mid Wing Straight Wings Conventional Tail

Figure 24: Proposed Design C


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Proposed design C is the weakest aircraft with respect to the stability subject, due to the fact

that placement of the wings is located in the middle section of the fuselage. No tapered section is

present on the wing. By placing wings in the mid-section, the maneuverability of aircraft is incremented.

Some of the disadvantages of this prototype are the construction of wings; due to the fact that the

complete wing is divided into two sections, and the connection between the fuselage and wing are very

complex, therefore heavy, and stability of aircraft decreases with respect to prototypes A and B.

3.5. Feasibility Assessment

Most of the advantages and disadvantages of the alternative designs previously exposed are

explained in the previous section. In order to choose the most efficient design, prototypes are compared

head to head in critical subjects such as stability, construction, lift capabilities, and efficiency.

Comparison between designs is presented in Table 5.

Table 5: Comparison Between Different Design Alternatives

Alternative Design A Alternative Design B Alternative Design C

Stability and

Control

Construction

Lift Capabilities

Efficiency

Total Check Marks 11 12 9

Evaluation on each of the subjects is performed by check marks, being 3 maximum value and 1

minimum.

As predicted before, design C is the weakest design with respect to stability and control. With

respect to construction, the only difference between designs A and B is the tail structure. Design A

utilizes T-Tail, whereas design B utilizes a conventional tail configuration. Due to physical characteristics

of vertical and horizontal stabilizers, construction of conventional tail is easier than T tail. Structural

connection between fuselage and empennage is also easier to construct with conventional tail due to

orientation of ribs present on the horizontal stabilizer. Construction of design C is complex because of

the required joints between fuselage and wing.


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Lift capabilities on wing depends on the selection of airfoil.

Overall efficiency of designs is the same considering that weight of aircrafts is similar, and lift

capabilities are the same if wings are evaluated with the same airfoil.


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3.6. Proposed Design

After careful review and study of the three main design alternatives, the proposed design is

selected to have the following configuration:

Table 6: Proposed Design Configuration

Wing Placement Wing Geometry Empennage Configuration

High Wing Tapered Wings Conventional Tail

Figure 25: Proposed Design

Configuration of the proposed design is similar to alternative design B. The only difference

between designs is the dihedral angle present on the tapered sections of the wing. Dihedral angle offers

more stability to aircraft but; construction wise; it is very complex to obtain desirable results. In this

aspect, the team does not want to take on unfeasible components that might not be present in the final

prototype, and that is the main reason of dropping dihedral angle out of the design. It is important to

mention that, since stability is crucial in the performance of the aircraft, dihedral angle is one of the

goals in the prototype construction process. Since dihedral angle is not a certainty, all aerodynamic

analysis to be performed in the prototype are completed with the physical characteristics that the

proposed design offers. As mentioned before, design of fuselage is performed in the aerodynamics

section. Final geometrical characteristics of fuselage are the result from various iterations decided from

the computational fluid dynamics analysis. Dimensions of each of the components are presented in the

proposed design are presented in the aircraft design section.


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4. Project Management

4.1. Overview

In order to successfully complete a project of this caliber and length, it is important to organize

and assign all tasks and assignments to everybody in the group. Putting together a timeline with

deadlines of major tasks helps keep the group on schedule to finish at or before the deadline and makes

sure that no job is forgotten. When creating the timeline it is crucial to have a finish date before the

deadline. This is done because at times different duties take longer than expected, and keeping a

conservative schedule prevents falling behind on time. Once the major tasks are known, it is important

to distribute them to all of the members in the group.

The following section demonstrates a more detailed description of the project management

used by the group in order to have completed all tasks and assignments before the given deadline.

4.2. Breakdown of Work into Specific Tasks

Throughout the development and production of the project, it was imperative that each of the

team members contribute to make possible the successful construction and testing of the remote

controlled airplane and competing to the best of the teams ability at the competition. Different tasks

were assigned to each of the three members to simplify the process of designing and building the

airplane.The aerodynamic design of the airplane is an extensive process that must be completed by at

least two of the members. An extensive amount of time must be put into computational fluid dynamics

analysis, since for this project, the research will be such that there will be no wind tunnel testing. This

will help the group decide on which of the proposed designs will best fit the predetermined

requirements relating to topics such as lift coefficients, drag coefficients, and pressure differentials and

distributions.

The analyzing and design of the control and stability of the airplane is another important task

that must not be taken lightly. Different designs and sizes of control surfaces must be taken into

consideration and studied. These control surfaces will allow the airplane to be maneuverable and stable

in flight, as required by the pilot and the environmental conditions it faces when airborne. These control

surfaces will also produce non-equilibrium accelerated motions such as maneuvers, if necessary.


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Extensive periods of time also will be taken into the construction of the remote controlled

airplane. New procedures and manufacturing techniques have to be designed for the custom airplane,

therefore having a reasonable amount of time for such task is crucial in achieving a timely construction

before the competition. Moreover, the making of custom parts that are out of the teams expertise, due

to several different reasons, have to be ordered, therefore time has to be allotted for such happenings.

Because of financial limitations imposed on international travel, in order to attend the 2010 SAE

Brazil AeroDesign Competition in Sao Jose dos Campos, the group had to come up with ideas to raise

money. The sole price of the airfare tickets from Miami to Sao Paulo, the closest non-stop city from

Miami, were approximately $1400 USD. The registration fee for the competition per group was

estimated near USD $350.

4.3. Organization of Work and Timeline

4.4. Breakdown of Responsibilities among Team Members

Miguel Jimenez was in charge of computational fluid dynamics and propulsion calculations.

Along with the help of Mechanical Engineering Masters Candidate, Mr. Stephen Wood, different wing,

fuselage, and empennage designs were run using OpenFOAM in the Multidisciplinary Analysis, Inverse

Design, Robust Optimization and Control Laboratory (MAIDROC) at the Engineering Center. Propulsion

Calculations were theoretically performed with the use of ThrustHP, a hobbyist computer program that

uses empirical data to theoretically estimate the thrust for a given engine and propeller selection, and

later compared to experimental results obtained with the use of a hanging scale, which served as a

dynamometer


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Both Miguel Jimenez and Ricardo Lugo were in charge of the aerodynamic design. Raw

calculations of parameters such as aspect ratios, coefficients of lift and drag, as well as plant form areas

are shown in the appendix section of the report.

Ricardo Lugo was in charge of calculations and design relating to stability and control.

Calculations of the size of control surfaces such as ailerons, the elevator, and the rudder were done by

Mr. Lugo.

Carlos Rojas was in charge of the radio control survey as well as the servos and channels. Along

with this Mr. Rojas was also in charge of the competition parameters. Throughout the design process, it

was being confirmed that everything that is being considered will be under the competition rules and

requirements for the airplane.

The three members were in charge of the prototype construction and fundraising activities.

Many proposals were sent out to different companies such as Florida Power and Light, Rockwell Collins,

and Honeywell. The FIUs College of Engineering and Computing, through Dr. Norman Munroe, was very

interested in the project and offered the pioneering team with $1,500 towards travel expenses. After

approaching American Airlines and explaining the goals and ambitions to compete in this competition in

Brazil, and becoming the first American team to participate in this competition, they offered the team a

sponsorship in which a 50% discount was provided to each of the airfare tickets.

4.5. Total Hours Spent on Project

In this section, an hour per hour table is displayed to calculate the total amount of time spent by

each team member on this project.

Miguel Jimenez

Topic Area Hours Spent Cost at

(25/hour)

Aerodynamic Research 50 1250

Open Foam Training 25 625

Aerodynamic Wing Design and Optimization 30 750

Propulsion Calculation and Propeller Selection 10 250

Report-Brazil 40 1000

Engine Training 8 200

Aircraft Construction 70 1750


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Testing/Brazil Travel 50 1250

Report- Florida International University 50 1250

Total Hours and Cost 333 $ 8325

Ricardo Lugo


(25/hour)

Structural Design and Stability and Control Research 50 1250

Aerodynamic Fuselage Design and Optimization 40 1000

Structural Aircraft Design 35 875

Stability and Control Analysis 40 1000

Report-Brazil 40 1000

Aircraft Construction 70 1750




Carlos Rojas


(25/hour)

Radio Control, Servo, Channel Research 50 1250

Competition parameters and Regulations 30 750

Nose and Landing Gear Design and Optimization 30 750

Report - Brazil 40 1000

Aircraft construction 70 1750





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4.6 Commercialization of Product

Although the final design and product is not a typical remote controlled aircraft that is bought

and flown by hobbyists and enthusiasts, it could have its unique uses and functions. When this project

was first introduced, one of the goals was to create a building block and a foundation for future groupsto attend SAE AeroDesign competition, both in the United States, and internationally in Brazil as well.

The airplane and performed calculations, for example, can be used in the years to come as a reference

for their own designs and airplanes, and for future generations of FIU students, fostering participation in

these types of events.


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5. Aerodynamic Design and Analysis

5.1. Introduction

The process of designing an aircraft is one that requires extensive planning and record keeping, due to

the many different aspects of the design that require synchronization and constant updating, after initial

assumptions are being made. In this sense, the design process mostly begins with the use of empirical

and historical data, and after some rough assumptions are made, design parameters are obtained which

then need to be revised again for further optimization of the aircrafts shape, so it can be said that the

design is an iterative process.

To expand this idea, after the constraints and givens of the airplane are given, the designer needs to

select the mission the airplane has to perform. After such mission is assigned, the process begins by

establishing the main criteria, e.g. the wing loading of the aircraft, which is a critical constant for several

more upcoming parameters in the airplane design process.

After empirical data is collected, more theoretical formulas are applied, especially those

provided in the Design of Aircraftbook by Thomas Corke. These formulas aid in the design of control

surfaces, empennage, even fuselage designs, but after a solid design is created, simple fluid mechanics

relations are required to estimate lift and drag values that point out the expected performance of the

airplane, which has to satisfy the constraints and givens in such design.

5.2. Main Wing Initial Design Parameters

5.2.1. Introduction

The main wing is the principal lifting surface of the aircraft. It is designed to carry the load of the

airplane when in flight. Therefore, as expected, it is considered the single most important feature in the

design of the aircraft. Its design was divided into three categories and their inner subcategories, the

latter being an initial estimate of the take-off weight, followed by the wing loading selection, which

further enabled the team to fully complete the wing.

Given the competition rules and restrictions on the construction of the aircraft, some of the

parameters are fixed and their values are kept constant or their range is specified, therefore altering the

regular design pattern for an airplane. This, in return, eased the task of design by having not to decide

between a very wide arrange of design parameters, but to only choose those needed to create the most

appropriate wing for the design.


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5.2.2. Estimate of Take-Off Weight

The take-off weight is a crucial factor to determine early in the design stage, because of its

importance for the design of many other parts of the airplane. In this case, the estimate of the take-off

weight is slightly easy to assign because of historical values and also because of competition restraints.

Given a fixed engine (O.S. .61 FX) and maximum take-off weight (MTOW) set to 20 kg, the team decided

to fix a target value of 18 kg for the preliminary take-off weight. In final stages on the design, this MTOW

will be reassessed to account for possible changes in the design and an initial breakdown of estimated

weights is further done.

Normally, this estimate splits the total weight of the aircraft into three basic categories, as shown in

Equation ( 1 ).

( 1 )

This equation, although extremely general, includes the three main weight divisions of the aircraft. Table

7 shows a breakdown of the weights at this stage.

Table 7: Estimated Take-Off Weight Estimates

Description Estimated Weight (kg)

Fuel 0.300

Payload 14.000

Empty Weight 3.700

TOTAL 18.000

After estimating the initial weight, the next crucial factor in the wing design is analyzed, the

wing loading.

5.2.3. Wing Loading Selection

The wing loading is defined as the ratio of the total weight of the aircraft with respect to the

planform area of the main wing, which in mathematical notation is defined as W/S. The wing loading has

a noticeable impact on many aspects of flight, including take-off and landing performance, as well as

glide and climb rates, according to Corke. Choosing a wing loading that suits one of these criteria before

mentioned hinders the aircraft performance on any of the other aspects, so it needs to be carefully

chosen to give priority to those aspects that the aircraft is primarily designed for.

WTO Wfuel Wpayload Wempty


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For this high-lift application, short take-off and landing is the single most important criterion. Equation (

2 ) clearly states the effect on the wing loading on take-off, therefore, for a given engine and a

maximum take-off length, it was deemed necessary to select a low wing loading so that the aircraft can

reach take-off speed VTO in the shortest time possible.

( 2 )

Carefully examining Equation ( 2 ), it can be seen that, if density and the lift coefficient are fixed, the

wing loading has a direct

saebrazilaerodesign-finalreport-fall2010

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