4-19-99aggie aquanauts2 presentation layout ( problem description and identification ( team...

4-19-99 Aggie Aquanauts 2

Presentation LayoutPresentation Layout

Problem Description and IdentificationProblem Description and Identification Team Architecture and Group Team Architecture and Group

ResponsibilitiesResponsibilities Technical PresentationsTechnical Presentations

• Aero Group - David Jamison and Todd GreggAero Group - David Jamison and Todd Gregg• Propulsion Group - Brian ClarkPropulsion Group - Brian Clark• Structures Group - Mike BlacetStructures Group - Mike Blacet

Financial OverviewFinancial Overview Highlight VideoHighlight Video Questions and CommentsQuestions and Comments


Competition Track:Competition Track:

Contest Restrictions:Contest Restrictions:• 100 Feet for Takeoff100 Feet for Takeoff

• Wing Span Less Than 9 FeetWing Span Less Than 9 Feet

• Structure Must Withstand 2.5g LoadingStructure Must Withstand 2.5g Loading

• Must be Propeller Driven by Commercially Available Electric MotorMust be Propeller Driven by Commercially Available Electric Motor

• Aircraft Take Off Gross Weight May Not Exceed 55 lbs.Aircraft Take Off Gross Weight May Not Exceed 55 lbs.

500 ft. 500 ft.

Contest Description and Contest Description and RestrictionsRestrictions


Problem Identification and Strategy Problem Identification and Strategy DevelopmentDevelopment

Takeoff Deemed Critical Flight PhaseTakeoff Deemed Critical Flight Phase How Much Weight Can We Lift?How Much Weight Can We Lift?

• Design SpreadsheetDesign Spreadsheet• Power Limit Feedback from the Propulsion Power Limit Feedback from the Propulsion

Group Group Selected Heavy Lift per Sortie StrategySelected Heavy Lift per Sortie Strategy

• Relatively Short Sortie PatternRelatively Short Sortie Pattern• Land, Taxi, Unload, Reload, Clear, TakeoffLand, Taxi, Unload, Reload, Clear, Takeoff

Landing Gear Became a Critical ComponentLanding Gear Became a Critical Component• Able to Carry and Absorb Impact LoadingAble to Carry and Absorb Impact Loading• Reduce Ground TimeReduce Ground Time


Introduction of Group LeadersIntroduction of Group Leaders

Chief Engineer - Mark Freeman

Aero Leader Propulsion Leader Structures Leader

David Jamison Scott St. John Mike Blacet


Aerodynamics GroupAerodynamics Group

Group MembersGroup Members

ResponsibilitiesResponsibilities• Design of the AircraftDesign of the Aircraft

– Wing / Airfoil Design and SelectionWing / Airfoil Design and Selection– Control Surface Sizing and Handling QualitiesControl Surface Sizing and Handling Qualities

• Aircraft Performance in ALL Flight PhasesAircraft Performance in ALL Flight Phases• MonokotingMonokoting

David Jamison Todd Gregg


Propulsion GroupPropulsion Group


Group ResponsibilitiesGroup Responsibilities• Selection and Testing of All Propulsive Selection and Testing of All Propulsive

ElementsElements– Motor, Gearbox, Propeller, and BatteriesMotor, Gearbox, Propeller, and Batteries

• Equipment Maintenance, Break-In, and Equipment Maintenance, Break-In, and AdjustmentAdjustment

Scott St. John Brian Clark Prasad Perera Roshani Jayasekara Mohammed Ali


Structures GroupStructures Group


Mike Blacet

Tiong Hoe Lim Wei Kian LimKok Leong ChooKek-Yau Tan

Eng Miau ChewEng Sheng NgoiAmanda Myers


Structures GroupStructures Group

Group ResponsibilitiesGroup Responsibilities• Structural Design and AnalysisStructural Design and Analysis• Selection of Construction MaterialsSelection of Construction Materials• Internal Layout and Component Internal Layout and Component

PlacementPlacement• Preparation of Construction DrawingsPreparation of Construction Drawings• Primary Construction GroupPrimary Construction Group

Aerodynamics Presentation:Aerodynamics Presentation:Todd GreggTodd Gregg

andandDavid JamisonDavid Jamison


Aerodynamics PresentationAerodynamics Presentation

Conceptual DesignConceptual Design• Conceptual SketchesConceptual Sketches• Rating the DesignsRating the Designs

Spreadsheet AnalysisSpreadsheet Analysis Tail ConfigurationsTail Configurations Stability and Control Surface SizingStability and Control Surface Sizing Detailed Design and RefinementsDetailed Design and Refinements


Conceptual DesignConceptual Design

ConceptualConceptual

SketchesSketches

Rating the DesignsRating the DesignsFigures of Merit Weight Factor A B C D

Ease of Construction 0.1 4 2 1 3Amount of Water 0.3 3 2 1 4Handling Capabilities 0.2 4 2 1 3Servo Location 0.1 3 2 4 1Propulsion Capability 0.1 3 1 2 4Cost of Production 0.2 4 2 3 1

Total Score 3.5 1.9 1.8 2.8


0

500

1000

1500

2000

2500

3000

3500

4000

55 53 51 49 47 45 43 41 39 37 35 33 31 29 27 25 23 21 19 17 15

Total Weight (lbs)

Power

(W)

Wing Area 9

Wing Area 10.8

Wing Area 12.6

Wing Area 14.4

Wing Area 16.2

Wing Area 18

Wing Area 19.8

Wing Area 21.6

Wing Area 23.4

Wing Area 25.2

Wing Area 27

Wing Area 28.8

Selected Design Range

Power Required vs. Total Weight

Spreadsheet AnalysisSpreadsheet Analysis

Design Spreadsheet OutputDesign Spreadsheet Output• Trend: Increase Weight - Increase Required Trend: Increase Weight - Increase Required

PowerPower• Propulsion Power Approximation ~ 1000 Propulsion Power Approximation ~ 1000

WattsWatts


Tail ConfigurationsTail Configurations

SketchesSketches

Rating the DesignsRating the DesignsFigures of Merit Weight A B C D

Ease of Construction 0.3 4 2 3 1

Control Surface Complexity 0.4 4 3 1 2

Servo Location 0.1 4 2 3 1

Weight 0.2 3 1 4 2

Total Score 3.8 2.2 2.4 1.6


Stability and Control Surface Stability and Control Surface SizingSizing

Stability and ControlStability and Control• Longitudinal Longitudinal • Lateral Lateral

Control Surface SizingControl Surface Sizing• ElevatorElevator• AileronsAilerons• RudderRudder

Elevator

Rudder


Detail Design and RefinementsDetail Design and Refinements

NACA ScoopsNACA Scoops• Provide Cooling Air For Provide Cooling Air For

BatteriesBatteries

Wing Tip PlatesWing Tip Plates

Scoop

• Reduce Vortex SheddingReduce Vortex Shedding• Improve Efficiency of WingImprove Efficiency of Wing


Detailed Design and Detailed Design and RefinementsRefinements

Aerodynamically Balanced RudderAerodynamically Balanced Rudder• Reduce Hinge MomentReduce Hinge Moment• Decrease Servo SizeDecrease Servo Size

Graphic Design and MonokoteGraphic Design and Monokote• Good VisibilityGood Visibility• AttractiveAttractive

Propulsion Presentation:Propulsion Presentation:Brian ClarkBrian Clark


Propulsion PresentationPropulsion Presentation

IntroductionIntroduction• Propulsive RestrictionsPropulsive Restrictions• Preliminary Analysis and ResearchPreliminary Analysis and Research

Motor SelectionMotor Selection Selected Motor’s CharacteristicsSelected Motor’s Characteristics Battery SelectionBattery Selection Propeller SelectionPropeller Selection System ModificationsSystem Modifications


IntroductionIntroduction

Propulsive RestrictionsPropulsive Restrictions• Propeller Driven by Electric MotorPropeller Driven by Electric Motor• Nickel Cadmium Battery Energy Nickel Cadmium Battery Energy

SourceSource

Preliminary Analysis and ResearchPreliminary Analysis and Research• Internet and Literature SurveyInternet and Literature Survey• Preliminary Trade Studies - ElectricalcPreliminary Trade Studies - Electricalc


Motor SelectionMotor Selection

Initial Target Power Output - 1000 Initial Target Power Output - 1000 WattsWatts• Design Spreadsheet for Target Design Spreadsheet for Target

Weight/Wing AreaWeight/Wing Area• Assume 50% System EfficiencyAssume 50% System Efficiency

Motor Alternatives ConsideredMotor Alternatives Considered• Aveox 1817/3YAveox 1817/3Y• Astro 90Astro 90

Figure of Merit Weight Factor Astro 90 Aveox 1817/3Y

Power Capabilites 0.4 4 3

Efficiency at High Current 0.4 4 3

Price 0.05 4 2

Availability 0.15 4 3

TOTAL 4 2.95


Selected Motor’s CharacteristicsSelected Motor’s Characteristics

Target Motor ParametersTarget Motor Parameters• Motor Efficiency vs. Current and VoltageMotor Efficiency vs. Current and Voltage• Heat Loss = IHeat Loss = I22RR


Battery SelectionBattery Selection

Considerations for Battery Considerations for Battery SelectionSelection• WeightWeight• Battery EfficiencyBattery Efficiency• Amount of Useful Power SuppliedAmount of Useful Power Supplied

Battery Alternatives ConsideredBattery Alternatives Considered• Capacitance: 3000 mAh - 4000 mAh - Capacitance: 3000 mAh - 4000 mAh -

4400 mAh - 5000 mAh - 7000 mAh 4400 mAh - 5000 mAh - 7000 mAh


Battery Power vs. WeightBattery Power vs. Weight

0

2

4

6

8

10

12

14

1200 1400 1600 1800 2000

Watts

Wei

ght (

lbs)

7000 mAh

5000 mAh

4400 mAh

4000 mAh

3000 mAh

Selected Capacitance


Battery Efficiency vs. Cell Battery Efficiency vs. Cell CapacitanceCapacitance

65

70

75

80

85

90

95

7000 5000 4400 4000 3000

Capacity (mAh)

% E

ffici

ency

Efficiency (%)Selected Capacity


Propeller SelectionPropeller Selection

Propeller Characteristics and EfficiencyPropeller Characteristics and Efficiency• P/D - Pitch to Diameter ratioP/D - Pitch to Diameter ratio

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00

J=v/nd

effi

cie

ncy

P/D=.5

P/D=.61

P/D=.725

P/D=.842

P/D=.960

P/D=1.082

• J - Advance RatioJ - Advance Ratio

Efficiency vs. Advance Ratio


System ModificationsSystem Modifications

Initial PerformanceInitial Performance• Motor Power Input:Motor Power Input:

– 1500 Watts @ 4500 RPM, Drawing 33 1500 Watts @ 4500 RPM, Drawing 33 AmpsAmps

Available SolutionsAvailable Solutions• Change the amount gear reduction Change the amount gear reduction • Increase the propeller diameterIncrease the propeller diameter• Advance the timing of the motorAdvance the timing of the motor


System ModificationsSystem Modifications

Comparison of various solutionsComparison of various solutions

Selected SolutionSelected Solution• Reduced gear ratio from 2.7:1 to 2.3:1Reduced gear ratio from 2.7:1 to 2.3:1• Advanced the motor timing to 15 degreesAdvanced the motor timing to 15 degrees

ResultsResults• Motor Power Input:Motor Power Input:

– 2400 Watts @ 5210 RPM, Drawing 50 2400 Watts @ 5210 RPM, Drawing 50 AmpsAmps

Run Pitch (in) Diameter (in) Ratio RPM PIN Motor (W) POUT Prop (W) Cost

1 20 22 2.73:1 4532 1610.3 821.3 $0.002 20 22 2.5:1 4858 1984.0 1011.8 $9.503 20 22 2.4:1 5012 2178.0 1110.8 $9.504 20 22 2.3:1 5172 2394.5 1221.2 $9.505 20 22 2.0:1 5702 3201.8 1636.0 $9.506 22 24 2.73:1 4388 2258.6 1151.9 $59.007 22 24 2.5:1 4676 2734.1 1394.4 $68.508 22 24 2.4:1 4792 3047.3 1554.1 $68.509 22 24 2.3:1 4949 3241.4 1653.1 $68.50

10 22 24 2.0:1 5399 4207.6 2145.9 $68.50Price of Parts: Propeller $59.00

Propeller Gear Box

New Gear $9.50

Structures Presentation:Structures Presentation:Mike BlacetMike Blacet


Structures PresentationStructures Presentation

IntroductionIntroduction• Preliminary Analysis and ResearchPreliminary Analysis and Research• Structures Group ArchitectureStructures Group Architecture

Fuselage DesignFuselage Design Wing DesignWing Design Landing Gear DesignLanding Gear Design


IntroductionIntroduction

Preliminary Analysis and ResearchPreliminary Analysis and Research• Internet and Literature SurveyInternet and Literature Survey• Construction, Analysis, and Testing of Construction, Analysis, and Testing of

Kit AirplaneKit Airplane• Analysis of Trade-Offs Between Design Analysis of Trade-Offs Between Design

AlternativesAlternatives Structures Group ArchitectureStructures Group Architecture

• Fuselage TeamFuselage Team• Wing TeamWing Team• Landing Gear TeamLanding Gear Team


Fuselage DesignFuselage Design

LongeronsLongerons• SpruceSpruce• Carbon FiberCarbon Fiber

SkinsSkins• 1/8 in. Balsa 1/8 in. Balsa

SheetSheet• Carbon FiberCarbon Fiber


Fuselage DesignFuselage Design

WingboxWingbox• LoadingLoading• Permanent Attachment to Center Wing Permanent Attachment to Center Wing

SectionSection

Longeron

Wing Spar

• Foam/Carbon FiberFoam/Carbon Fiber


Wing DesignWing Design

SparsSpars• Double SparDouble Spar• SpruceSpruce• Carbon FiberCarbon Fiber

Shear WebsShear Webs• Foam/Carbon Foam/Carbon

FiberFiber Center Wing Center Wing

SectionSection


Landing GearLanding Gear

Critical ComponentCritical Component• Magnitude of LoadMagnitude of Load• Ground HandlingGround Handling

Main GearMain Gear• Rectangular Aluminum ShaftRectangular Aluminum Shaft• Compression SpringCompression Spring• Located in WingLocated in Wing• Hard Rubber Wheels with BearingsHard Rubber Wheels with Bearings


Landing GearLanding Gear

Nose GearNose Gear• Circular Aluminum ShaftsCircular Aluminum Shafts• Compression SpringCompression Spring• Tilted Forward at 7° AngleTilted Forward at 7° Angle• Steering Steering • BrakingBraking

$$

$$

$ $

$

$

$ $

$Financial Overview:Financial Overview:

Mark FreemanMark Freeman


Expected Actual

Consumable Material $102.30 $101.10Mechanical and Electrical Material $1,105.00 $1,659.00Construction Material $445.00 $937.50Total $1,652.30 $2,697.60

Total Cost by Category

Expenditure ReviewExpenditure Review

Cost by CategoryCost by Category

61%

35%

4%

Consumable

Mech and Elec

Construction

4-19-99aggie aquanauts2 presentation layout ( problem description and identification ( team...

Documents

aircraftwing airfoil

gross weight

critical flight phasehow

critical componentable

heavy lift

batterieswing tip platesscoop

vortex shedding

strategy developmenttakeoff