Critical Design Review AAE451 – Team 3 Project Avatar December 9, 2003 Brian Chesko Brian Hronchek...

Critical Design Review

AAE451 – Team 3

Project Avatar

December 9, 2003Brian CheskoBrian HronchekTed LightDoug MousseauBrent Robbins Emil Tchilian

2

AAE 451Team 3Team 3ProjectProject AvatarAvatar Aircraft Name

Avatar

av·a·tar - n. - 1. <chat, virtual reality> An image representing a user in a multi-user virtual reality.

Source: The Free On-line Dictionary of Computing

http://wombat.doc.ic.ac.uk/foldoc/

3

AAE 451Team 3Team 3ProjectProject AvatarAvatar Introduction

• Walk Around• Design Requirements and Objectives• Sizing• Propulsion• Aerodynamics• Dynamics and Controls• Structures• Performance• Cost• Summary• Questions

4

AAE 451Team 3Team 3ProjectProject AvatarAvatar Aircraft Walk Around

•Low wing – Clark Y•Tricycle Gear

•T-Tail – NACA 0012

•Pusher

•Wing Span = 14.4 ft

•Wing Chord = 2.9 ft

•A/C Length = 10 ft

•Internal Pod

5

AAE 451Team 3Team 3ProjectProject AvatarAvatar Design Requirements & Objectives

• Maximum weight < 55 lbs

• Cruise speed > 50 ft/sec

• Stall speed < 30 ft/sec

• Climb angle > 5.5°

• Operating ceiling > 1000 ft

• Flight time > 30 minutes

• Payload of 20 lbs in 14”x6”x20” pod

• Carry pitot-static boom

• Spending limit < $300

• T.O. distance < 106 ft (~60% of McAllister Park runway length)

• Rough field capabilities

• Detachable wing

• Easy construction

6

AAE 451Team 3Team 3ProjectProject AvatarAvatar Constraint Diagram

Aircraft Constraint Diagram

0

4

8

12

16

20

24

28

32

36

40

0 0.25 0.5 0.75 1 1.25 1.5 1.75 2

W/S (lbf/ft^2)

W/P

(lb

f/sh

p)

Cruise Speed

Stall Speed

Climb

T/O dist

Landing dist

Ceiling

Endurance

Minimum Structure

Minimum Power

Power Loading = 15.5 lbf/shpWing Loading = 1.28 lbf/ft^2

7

AAE 451Team 3Team 3ProjectProject AvatarAvatar Propulsion

8

AAE 451Team 3Team 3ProjectProject AvatarAvatar Chosen Engine

• O.S. Max 1.60 FX-FI– 3.7 BHP @ 8500 RPM– 1,800-9,000 RPM– 2.08 lbs– Fuel Injected

Ref. www.towerhobbies.com

9

AAE 451Team 3Team 3ProjectProject AvatarAvatar Chosen Propeller 4-blades• Zinger 16X7 Wood Pusher Propeller

– 16 inches in diameter with 7 inch pitch– 4 blades

Ref. www.zingerpropeller.com

10

AAE 451Team 3Team 3ProjectProject AvatarAvatar Chosen Fuel Tank

• Fuel tank chosen is:– Du-Bro 50 oz. fuel

tank– Available from

Tower Hobbies– Located at the C.G.

of aircraft– Good for up to 32

min. of flight time (when completely full).

34 ( )

8in deep

13 ( )

2in

38 ( )

8in


11

AAE 451Team 3Team 3ProjectProject AvatarAvatar Takeoff EOM Integration

WDTag

W

ThrustDrag + Rolling Friction

0 20 40 60 80 100 1200

5

10

15

20

25

30

35

Position [ft]

Vel

ocity

[ft

/s]

Velocity vs. Position at Takeoff

Position [ft]

Vel

ocity

[ft/s

]

Velocity vs. Position at Takeoff

Takeoff Distance Within Constraint

12

AAE 451Team 3Team 3ProjectProject AvatarAvatar Max Velocity

30 40 50 60 70 80 90 1000

2

4

6

8

10

12

14

16

18

20

Flying Velocity [ft/s]

Th

rust

/Dra

g [

lbf]

Maximum Velocity

Thrust

Drag

13

AAE 451Team 3Team 3ProjectProject AvatarAvatar Aerodynamics

14

AAE 451Team 3Team 3ProjectProject AvatarAvatar Wing Dimensions

• Prandtl’s Lifting line theory used for aerodynamic modeling of the lifting components• Input parameters: AR, a0, L=0, .

• Lifting Line Model Gives CL, CDi at prescribed • CDvisc found using Xfoil which was used to obtain

CD = CDi+CDvisc

5° Dihedral

15

AAE 451Team 3Team 3ProjectProject AvatarAvatar

-1 -0.5 0 0.5 1 1.50.005

0.006

0.007

0.008

0.009

0.01

0.011

0.012

0.013

0.014

0.015

Section Lift Coefficient, cl

Sec

tion

Dra

g C

oeff

icie

nt,

c d

Drag Polar for Candidate Airfoils

NACA 441244154425241823018ClarkY

Airfoil Selection

Region of Interest

Clark Y Airfoil has low drag over range of interest

Clark Y

16


-10 -8 -6 -4 -2 0 2 4 6 8 10-1

-0.5

0

0.5

1

1.5

2

Angle of Attack

Sec

tion

Lift

Coe

ffic

ient

, c l

-1 -0.5 0 0.5 1 1.5 20.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

0.05


Sec

tion

Dra

g C

oeff

icie

nt,

c d

Airfoil SelectionClark Y Airfoil

-0.2

-0.1

0

0.1

0.2

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

X/C

Y/C

Section Lift Coefficient Cl

Se

ctio

n D

rag

Co

eff

icie

nt

Cd

Angle of Attack (AOA)

Se

ctio

n L

ift C

oe

ffic

ien

t C

l

17

AAE 451Team 3Team 3ProjectProject AvatarAvatar Wing Stall Performance

• CL needed = 1.19• Wing without flaps

reaches CL at =13°• Wing stall possible • Wing with 15° flap

deflection reaches CL at 11°

-10 -5 0 5 10 15-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4CL vs aoa for different flap deflections

aoa (deg)

CL

CL no flapCL 10 deg flapCL 15 deg flap Required CL

Flaperons necessary to meet stall requirements

CL

Angle of Attack (degrees)

18

AAE 451Team 3Team 3ProjectProject AvatarAvatar Wing Performance

-0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.40

0.02

0.04

0.06

0.08

0.1

0.12

0.14CD vs CL for different flap deflections

CL

CD

CDvsCL no flapCDvsCL 10 deg flapCDvsCL 15 deg flap

Required CL at stall

C D

CL

19

AAE 451Team 3Team 3ProjectProject AvatarAvatar Drag Build Up At Cruise

Component CD Drag

Wing 0.018 2.6 lbf

Fuselage 0.0045 0.6 lbf

Horizontal Tail

0.0043 0.6 lbf

Vertical Tail 0.0017 0.04 lbf

20

AAE 451Team 3Team 3ProjectProject AvatarAvatar Wing Operating Parameters

CL(of wing)

Flaperon Deflection

CD L/D

Stall 1.19 11° 15° 0.119 10

T/O 0.989 8° 15° 0.084 12

Cruise 0.44 2.8° 0° 0.018 24

21

AAE 451Team 3Team 3ProjectProject AvatarAvatar Dynamics and Controls

22

AAE 451Team 3Team 3ProjectProject AvatarAvatar Center of Gravity & Aerodynamic Center

• Aircraft Center of Gravity is 3.2 ft from nose.– Calculated from CAD program Pro-E

• Aircraft Aerodynamic Center is 3.7 ft from nose.– Position where pitching moment of aircraft doesn’t change with

angle of attack– Calculated using Lift from Wing and Horizontal Tail

Center of Gravity

Aerodynamic Center

23

AAE 451Team 3Team 3ProjectProject AvatarAvatar Static Margin

8 9 10 11 12 13 14 152.8

3

3.2

3.4

3.6

3.8

4

Horizontal Tail Area (ft2)

Dis

tanc

e fr

om N

ose

of A

ircra

ft =

> x

(ft)

Position on Aircraft vs. Horizontal Tail Area

Aerodynamic Center of Aircraft

Static Margin = 20%

Static Margin = 15%

Center of Gravity

15% 20%

ac cg

wing

X XSM

c

• Desired Static Margin is 15% - 20%– Dependent on C.G. and A.C. location

• Static Margin is 15%• Contributes to

Horizontal Tail Sizing

24

AAE 451Team 3Team 3ProjectProject AvatarAvatar Horizontal Tail Sizing

• Tail sized based on desired static margin for static stability and take-off rotation ability double-dot should be at least 10 deg/sec2

Area 12 ft2

Span 6 ft

Chord 2 ft

6 ft

2 ft

10.1 10.15 10.2 10.25 10.3 10.35 10.4 10.456

7

8

9

10

11

12

13

14

15

16

The

ta D

oubl

e D

ot a

t In

stan

t of

Rot

atio

n (d

eg/s

ec2 )

Horizontal Tail Area (ft2)

Concrete

Long Grass

0.02g

0.10g

Ref. Roskam, Airplane Flight Dynamics

25

AAE 451Team 3Team 3ProjectProject AvatarAvatar Vertical Tail Sizing

• Value of yawing coefficient due to sideslip angle should be approximately 0.001 = 10e-4

• Tail area should be ~2 ft2

0 0.5 1 1.5 2 2.5 3-5

0

5

10

15

20x 10

-4

Vertical Tail Area (ft2)

CN

b [de

g- 1]

Coefficient of Yaw Moment due to Sideslip vs Vertical Tail Area

Area 2 ft2

Span 1 ft

Chord 2 ft

1 ft2 ft

Ref. Roskam, Airplane Design

26

AAE 451Team 3Team 3ProjectProject AvatarAvatar Dihedral Angle

Recommendations• Survey of Roskam data on homebuilt &

agricultural low-wing aircraft: ~5°• “Wing and Tail Dihedral for Models” - McCombs

– RC w/ailerons (for max maneuverability, low wing): 0-2° EVD (Equivalent V-Dihedral ≈ dihedral)

– Free Flight Scale model low wing: 3-8° EVD

5° dihedral is a good compromise

27

AAE 451Team 3Team 3ProjectProject AvatarAvatar Control Surface Sizing

• Sizes calculate from traditional lifting device percentages.

Flaperon Elevator Rudder

Chord 0.58 ft 0.6 ft 0.6 ft

Inboard Position 0.95 ft 0.2 ft 0.1 ft

Outboard Position 7.2 ft 3 ft 1 ft

Ref. Roskam, Airplane Design

6.25 ft

2.8 ft

0.58 ft

0.6 ft

0.6 ft

0.9 ft

28


-8 -6 -4 -2 0 2 4 6 8 10 12-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

Alpha of Aircraft

Cm

of

Airc

raft

C.G

.

Cm of Aircraft vs. Alpha of Aircraft at Cruise with 0 Degree Flaperon Deflection

Elevator Deflection = -25 [degrees]-20-15-10-505

Trimming• Incidence of Horizontal Tail calculated from trimmed

flight during cruise (0 Angle of Attack)• Analysis set

incidence at

-2

29

AAE 451Team 3Team 3ProjectProject AvatarAvatar Structures

30

AAE 451Team 3Team 3ProjectProject AvatarAvatar Wing Spar Design

2 Spar Design (at .15 & .60 chord):

• Resist Bending

• Assuming 5-g loading

• 53 lbf weight

• Safety factor of 1.5

• Resist Torsion

• Less than 1o twist at tip under normal flight conditions

Spar Results:

• Material of Choice: Bass or Spruce Wood

• Front Spar:

• 3.6” high (based on airfoil)

• 0.37” thick (0.73” at root)

• Rear Spar:

• 3” high (based on airfoil)

• 0.16” thick (0.25” at root)

31

AAE 451Team 3Team 3ProjectProject AvatarAvatar Longitudinal Beam Design

2 Beam Design:

• Resist Bending from:

• 20 lbf payload

• Horizontal tail loads

• Resist Torsion from:

• Rudder deflections

• Prop wash over tail

Beam Results:

• Material of Choice: Bass or Spruce Wood

• Beam Dimensions:

• 3” high

• 0.25” thick

• 8” between the beams

32

AAE 451Team 3Team 3ProjectProject AvatarAvatar Tail Structures

• Horizontal and vertical tails comprised of carbon fiber w/ foam core

• Possible to make two foam cores, and cure entire tail at one time

• Control surfaces just need to be cut out of tail structure

• Tail spars allow attach points and transfer load to beams

Foam core with carbon fiber shell

33

AAE 451Team 3Team 3ProjectProject AvatarAvatar Rear Gear Design

• Blue lines represent pin joints

• Black tie-downs absorb energy from landing

• Up to a 33 ft/sec “crash” from 5 feet high

• Need 18” relaxed length tie-down

• Square aluminum tube transfers landing load to tie-downs and surrounding structure

• 1” x 1” x 0.065” thick – 6063-T6

34

AAE 451Team 3Team 3ProjectProject AvatarAvatar Front Gear Design

Elastic Band & Nylon Bolt

• Elastic Band Absorbs some energy from landing

• Nylon bolt breaks during hard landing

Aluminum Bolt

•Provides pivot for gear (does not break)

Front Gear Aluminum Tube

• Designed not to break

• Designed not to bend

• Al tube:

1” x 1” x 0.065” thick 6063-T6

35

AAE 451Team 3Team 3ProjectProject AvatarAvatar Other Odds and Ends

• Covering for Wing:– Coverite 21st Century Iron

on Fabric– 0.34 oz/ft2

– Stronger, and resists tears better than MonoKote

• Covering for Fuselage:– Fiberglass

• Either mold or foam core• Not conductive – won’t

interfere with internal electronics


36

AAE 451Team 3Team 3ProjectProject AvatarAvatar Final Weight Estimate

Part Description Weight (lbf)Propulsion 50 oz fuel tank 0.38

O.S. 1.60 FX 2.04Sliencer E-5010 0.66Fuel (30 min. based on O.S. info) 2.2016X7 4-Blade Prop 0.47

Structures Bass/Spruce Wing Spars 4.4021st Century Fabric 1.74Ribs 0.70Bass/Spruce Tail Beam 2.15Fuselage Skin (1 ply of E-glass) 2.78V-Stab Foam Core 0.55H-Stab Foam Core 2.77V-Stab Carbon Fiber Covering (1 ply Carbon-Fiber) 0.37H-Stab Carbon Fiber Covering (1 ply Carbon-Fiber) 1.69Engine Supports 0.15Tail Spars 0.35

Landing Gear Rear Gear 2.90Front Gear 0.42Smooth Wheels 4" 0.61Bungees 0.20

Electronics Pod 20.009 channel R149DP PCM 0.08MP-2000 (includes all components) 0.40Servos - S3104 1.26Wires 0.25Battery for Receiver FUTM 1280 0.50

Miscellaneous 3.00

Total 53.01

37

AAE 451Team 3Team 3ProjectProject AvatarAvatar Performance

38

AAE 451Team 3Team 3ProjectProject AvatarAvatar Aircraft Performance

PARAMETER VALUE (Approx)Endurance (at cruise) 30 minRange (at cruise) 17 milesMinimum Flight Velocity 30 ft/secRate of Climb (at takeoff conditions) 7.5 ft/secMaximum Velocity 90 mphClimb Angle 13.1 deg

90 ft/sec

(with 2.2lbf fuel)

39

AAE 451Team 3Team 3ProjectProject AvatarAvatar Cost

40

AAE 451Team 3Team 3ProjectProject AvatarAvatar Airframe Cost

Part Description Brand Quantity Cost/unit Total CostBass/Spruce Wing Spars n/a 2 $15.00 $30.0021st Century Fabric Coverite 4 $39.99 $159.96Ribs n/a 21 $0.98 $20.58Bass/Spruce Tail Beam n/a 2 $10.00 $20.00Fuselage Skin (1 ply of E-glass) n/a HAVEV-Stab Foam Core n/a 1 $15.00 $15.00

H-Stab Foam Core n/a 2 $15.00 $30.00V-Stab Carbon Fiber Covering (1 ply) n/a HAVEH-Stab Carbon Fiber Covering (1 ply) n/a HAVEEngine Supports n/a 1 $5.00 $5.00Tail Spars 2 $5.00 $10

Rear Gear n/a 4 $4.74 $18.96

Front Gear n/a 1 $4.74 $4.74Smooth Wheels 4" Sullivan Skylite 3 $12.39 $37.17Bungees Tool Shop 2 $1.50 $3.00Misc (Bolts, Nuts, Washers, etc) $25.00

TOTAL $379.41

41

AAE 451Team 3Team 3ProjectProject AvatarAvatar Electronics Cost

Part Description Brand Quantity Cost/unit Total CostPOD 1Onboard Laptop Computer Dell Latitude C610 1 $2,566.80 $2,566.80MIDG 1 $6,750.00 $6,750.00MIDG Power Supply uINS Power Supply 1 not determinedCamera Canon PowerShot G5 1 $1,500.00 $1,500.00

National Instrument PCMCIA DAQ Card Enterasys (CSICD-AA-128) 1 $1,195.00 $1,195.00

Wireless Network Card CSICD-AA-128 1 $80.00 $80.00Vehicle Mount Antenna -- Enterasys CSIES-AA-M05 1 $85.00 $85.00Vehicle Mount Antenna Cable CSIES-AA-PT250 1 $65.00 $65.00Range Extending Antenna CSIBB-IA 1 $80.00 $80.00AVIONICS

9 Channel R149DP PCM (Included w/Trans) Futaba 1 $139.95 $139.95

MP-2000 (includes all components) Micropilot HAVEServos - S3104 Futaba 6 $32.99 $197.94Wires 6 $4.00 $24.00Battery for Receiver FUTM Futaba 1 $44.99 $44.99

TOTAL $12,728.68

42

AAE 451Team 3Team 3ProjectProject AvatarAvatar Propulsion Cost

Part Description Brand Quantity Cost/unit Total Cost50 oz fuel tank Dubro 1 $11.49 $11.49O.S. 1.60 FX-FI O.S. 1 $714.99 $714.99Sliencer E-5010 Bisson-Pitts 1 $49.99 $49.99Engine Mount O.S. 1 $26.99 $26.9916X7 4-Blade Prop Zinger 1 $54.60 $54.60

TOTAL $858.06

43

AAE 451Team 3Team 3ProjectProject AvatarAvatar Total Aircraft Cost

What Purdue Will Pay For This Project

Airframe Cost $379.41Electronics Cost $12,728.68Propulsion Cost $858.06

TOTAL $13,966.15

44

AAE 451Team 3Team 3ProjectProject AvatarAvatar Total Aircraft Value

• Total Aircraft Value = (Engineering Pay) + (Cost) + (Value of Already Possessed Parts)

• Engineering Pay = 823.75 hr x $100/hour = $82,375• Aircraft Cost = $13,966.15• Value of Already Possessed Parts = $10,000

– Micropilot = $5,000– Carbon Fiber & E-Glass = $5,000 (estimate)

TOTAL AIRCRAFT VALUE = $106,341.15

What Purdue Would Pay to Outsource This Project

45

AAE 451Team 3Team 3ProjectProject AvatarAvatar Summary

46

AAE 451Team 3Team 3ProjectProject AvatarAvatar Summary – Internal View

Camera View

Internal Pod

47

AAE 451Team 3Team 3ProjectProject AvatarAvatar Summary – 3-View

48

AAE 451Team 3Team 3ProjectProject AvatarAvatar Summary -Major Design Points

• Aircraft Description– Aspect Ratio = 5– Wing Span = 14.4 ft– Wing Area ~ 42 ft2

– Aircraft Length = 10 ft (not including air data boom)

– Engine = 3.7 hp O.S. 1.60 FX-FI – Fuel Injected

– Weight = 53 lbf

• Aircraft Configuration– T-Tail– Low Wing– Pusher– High Engine– Tricycle Gear– Internal Pod

49

AAE 451Team 3Team 3ProjectProject AvatarAvatar Questions?

50

AAE 451Team 3Team 3ProjectProject AvatarAvatar References (I)

•[1] MATLAB. PC Vers 6.0. Computer Software. Mathworks, INC. 2001

•[2] Raymer, Daniel P., Aircraft Design: A Conceptual Approach, AIAA Education Series, 1989.

•[3] Roskam, Jan., Airplane Flight Dynamics and Automatic Flight Controls. Part I. DAR Corporation, Kansas. 2001

•[4] Gere, James M., Mechanics of Materials. Brooks/Cole, Pacific Grove, CA. 2001

•[5] Tower Hobbies. 9 December 2003. http://www.towerhobbies.com

•[6] XFoil. PC Vers. 6.94. Computer Software. Mark Drela. 2001.

•[7] Niu, Michael C., Airframe Structural Design, Conmilit Press Ltd. Hong Kong. 1995.

•[8] Halliday, et al., Fundamentals of Physics, John Wiley & Sons. New York. 1997.

•[9] Roskam, Jan, Airplane Design (Parts I-VIII), Roskam Aviation and Engineering Corp. Ottawa KS. 1988.

•[10] Kuhn, P., “Analysis of 2-Spar Cantilever Wings with Special Reference to Torsion and Load Transference”. NACA Report No. 508.

•[11] McMaster-Carr. 9 December 2003. http://www.mcmaster.com

•[12] Pro/ENGINEER. PC Release 2001. PTC Corporation.

•[13] Roskam, Jan., Methods for Estimating Stability and Control Derivatives of Conventional Subsonic Airplanes. Publisher Jan Roskam. Lawrence, KS. 1977.

http://www.towerhobbies.com/

51

AAE 451Team 3Team 3ProjectProject AvatarAvatar References (II)

•[14] Zinger Propeller. 9 December 2003. http://www.zingerpropeller.com

•[15] McCombs, William F., “Wing and Tail Dihedral for Models”, Model Aviation. Dec. 1994. 104-112.

http://www.zingerpropeller.com/

52

AAE 451Team 3Team 3ProjectProject AvatarAvatar Appendix

SIZING

54

AAE 451Team 3Team 3ProjectProject AvatarAvatar Cruise Speed

S

W

CVSHP

W

S

WSHP

W

CVSHP

S

CVSHPVTP

Dcruise

p

Dcruise

p

Dcruisepout

3

3

3

out

2550)75.0(

2550)75.0(

give togrearrangin

2

1)75.0(550

gives drag thrust toequating and velocity,mes thrust ti toP Equating

)(Pr67.0

)(50

)1000(002309.0

)Aero (0275.0

3

opulsion

Andrisanis

ftV

ftft

slug

C

p

cruise

D

55

AAE 451Team 3Team 3ProjectProject AvatarAvatar Stall Speed

max2

max2

2

1

gives grearrangin and

2

1

liftfor equation with theStarting

Lstall

Lstall

CVS

W

SCVL

)(30

)(002378.0

)(2.1

3

max

Andrisanis

ftV

levelseaft

slug

flapsC

stall

L

56

AAE 451Team 3Team 3ProjectProject AvatarAvatar Climb Angle

sin Thrust

Weight

1

Lift

Drag

ThrustSHP p 550

V

)(2.1

)(30

0275.0

67.0

max flapsC

Andrisanis

ftV

C

L

stall

D

p

Weight

SHP

550 p

sin 1

C Lmax

C D

Vstall 1.1

57

AAE 451Team 3Team 3ProjectProject AvatarAvatar Ceiling

242

2

4

)1100(

gives grearrangin

/

:power excess specificfor equation with theStarting

0

0

SW

KnVC

VSW

SHP

W

and

S

W

q

Kn

SW

qC

W

TVP

cruiseD

cruisep

Ds

0.1

)(50

)1000(002309.0

67.0

3

n

Andrisanis

ftV

ftft

slug

cruise

p

58

AAE 451Team 3Team 3ProjectProject AvatarAvatar Endurance

64.0)045.01(78.1

))((

1k

:Where

5503

4

1

2

1

:classin given equation endurance with Starting

68.0

4

3

0

0

ARe

eAR

gk

C

C

SWP

W D

Dcruise

5

025.00

AR

CD

59

AAE 451Team 3Team 3ProjectProject AvatarAvatar Takeoff

.21TOP gives TOPfor lly quadratica Solving ft. 105 iss and

009.09.4s

as 3.4)(Equation Roskamby defined is TOP where

P

W

gives Roskam from (3.2)Equation Using

2323TOG

22323TOG

23

23max /

TOPTOP

S

W

TOPCOTL

fts

RoskamCC

TOG

SL

TO

LLTO

105

98.0

)(21.1/max

60

AAE 451Team 3Team 3ProjectProject AvatarAvatar Landing Distance

25.0

2

max*/2

687.1

1265.0

:speed stallfor equation previous Inserting

265.0

:distance landingfor equation with Starting

Llanding

stalllanding

CS

WD

VD

)(002378.0

)(2.1

3

max

levelseaft

slug

flapsCL

62

AAE 451Team 3Team 3ProjectProject AvatarAvatar Appendix

• OS 1.60 FX-FI

• Consistency: The Fuel Injection system constantly supplies the correct air/fuel mixture to the engine, regardless of speed, altitude, or attitude.

• Recommended is a 450-550cc fuel tank that allows approximately 10 to 12 minute flights. = 30 min. with 50 oz. tank.

64

AAE 451Team 3Team 3ProjectProject AvatarAvatar Aerodynamic Modeling

iLl

cVaa

c

000

2

nAbVN

nn sin2)(

1

sin

sin)(

1

nnA

N

nni

Prandtl’s Lifting line theory used for aerodynamic modeling of the lifting components

Solving Prandt’s equation

Substituting:

Equation to solve:0

110 sin

sinsin

4

L

N

nn

N

nn

nnAnA

ca

b

•System of N equations with N unknowns (Solve N N matix)•Take N different spanwise locations on the wing where the equation is to be satisfied: 1, 2, .. N; (but not at the tips, so: 0 < < )•The wing is symmetrical A2, A4,… are zero

•Take only A1, A3,… as unknowns•Take only control points on half of the wing: 0 < i /2

Main Results CL = πAR*A1*(α- αLo) 0where)1(2

2

1

2

N

n

nLD A

An

A

CC

i

65

AAE 451Team 3Team 3ProjectProject AvatarAvatar Choice of main wing airfoil

From lifting line with Initial parameters:

•Rectangular planform, 1000 ft •a0 = 2pi, •αL0 = 0,•AR = 5;•W/S = 1.28 (from sizing) •CL = 0.4437

0 1 2 3 4 5 6 7 80

0.1

0.2

0.3

0.4

0.5

0.6

0.7

ClCd*10alpha

i*10

Cl distribution found at cruiseCl varies :0 to 0.58

Taking into account the Cl variation above, the need of an airfoil with a drag bucket at the specified Cl’sXfoil utilized for different foils at the above conditions

66


-1 -0.5 0 0.5 1 1.50.005

0.006

0.007

0.008

0.009

0.01

0.011

0.012

0.013

0.014

0.015


Sec

tion

Dra

g C

oeff

icie

nt,

c d

Drag Polar for Candidate Airfoils

NACA 441244154425241823018ClarkY

Airfoil Selection

Region of Interest

Clark Y Airfoil Drag Bucket location fits best

Clark Y

67

AAE 451Team 3Team 3ProjectProject AvatarAvatar ClarkY foil

-0.2

-0.1

0

0.1

0.2

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

x/c

y/c

-10 -5 0 5 10 15-0.5

0

0.5

1

1.5

2

-10 -5 0 5 10 15-0.5

0

0.5

1

1.5

2Cl vs aoa

aoa (deg)

Cl

no flap10deg15 degCruise

Xfoil runs of ClarkY foil

at cruise and take-off

Cruise: αL= -3.5deg

Takeoff no flap: αL= -3.8deg

Takeoff 10deg flap: αL= -7deg

Takeoff 15deg flap: αL= -7.8deg

In lifting Line Equation:

a0 – updated depending on condition

αL - updated according to above

68


Stall Performance

• CL needed = 1.19• Wing without flaps

reaches CL at 13 deg aoa

• Wing stall possible • Wing with 15 deg flap

deflection reaches CL at 11 degrees

-10 -5 0 5 10 15-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4CL vs aoa for different flap deflections

aoa (deg)

CL

CL no flapCL 10 deg flapCL 15 deg flap

Required CL

Flaperons necessary to meet stall requirements

69

AAE 451Team 3Team 3ProjectProject AvatarAvatar Stall Performance Drag Calculation

-0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.40

0.02

0.04

0.06

0.08

0.1

0.12

0.14CD vs CL for different flap deflections

CL

CD

CDvsCL no flapCDvsCL 10 deg flapCDvsCL 15 deg flap

Required CL

CD = 0.119 at required CL

CDtotal = CDinduced+CDvisc

CDinduced – from Lifting line

CD visc – integrated at the found Cls

-0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.60.005

0.01

0.015

0.02

0.025

0.03

0.035

cl

cd

Viscous Drag Coefficient calculaton

original datapolyfit functionvalues for our cl from polyfit funtion

70


Cruise Performance

-6 -4 -2 0 2 4 6 8 10 12 14-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6CL,cl vs aoa

aoa deg

3D CL2D cl

CL needed = 0.44 CL achieved at 2.8 deg

-6 -4 -2 0 2 4 6 8 10 12 140

0.02

0.04

0.06

0.08

0.1

0.12Cd,CDtotal vs aoa

aoa (deg)

Cd,

CD

3D CD totalCd visc 2d

Total Lift produced = 57lbf

Total Drag = 2.6 lbf, L/D =21

71


Operating Parameters

CL AoaFlap

DeflectionCD L/D

Stall 1.19 11 deg 15 deg 0.119 10

T/O 0.989 8. deg 15 deg 0.084 12

Cruise 0.44 2.8 deg 0 deg 0.018 24

73

AAE 451Team 3Team 3ProjectProject AvatarAvatar Center of Gravity

• Center of Gravity of Aircraft– Weight of Horizontal Tail changes with area

9

1i i

iAircraft

Total

W xCG

W

20.44HT HT

lbsW Area

ft

Note: 0.44 lbs/ft2 based on aircraft sizing code

74

AAE 451Team 3Team 3ProjectProject AvatarAvatar Aerodynamic Center• Aerodynamic Center as a function of Horizontal Tail

Area1

1 1

wing hh

Aircraft

h

h hac L ac

ach h

L

d SX C X

d SX

d SC

d S

Roskam Eq 11.1

ac ac wingX X c 0.49hd

d

13.6h

LC rad

Raymer Fig 16.12

75

AAE 451Team 3Team 3ProjectProject AvatarAvatar Takeoff Rotation Equation

• This sizing based on angular acceleration during take-off rotation

Ref. Roskam 421 book, pg 288-290

Variable definitions found in above reference

max

2

( ) ( ) ( )

( )( )

( )( )

g g g g g g g g

g g wf g g wf mgg g

g h g g gh gground

cg mg g cg g mg g D cg cg T

wf mg ac g cg g mg ac yy

hL h rotate ac mg g mg g cg

W x x z z D z z T z z

L x x z z M IS ft

C q x x z z

76

AAE 451Team 3Team 3ProjectProject AvatarAvatar Yaw Moment due to Sideslip

• Vertical Tail sized from Coefficient of Yaw Moment due to Sideslip

wb v

n n L V VC C C S S x b

1

0 57.3wb f sW

n n n N R f fC C C K K S l Sb

Due to Wing and Fuselage:

Roskam Eq 11.8Vol 2

Roskam Eq 10.42Vol 6

13.6v

LC rad

5.7Vx ft

241.76S ft

14.4b ft

77

AAE 451Team 3Team 3ProjectProject AvatarAvatar Dihedral Angle

EVD = A + kB

A = 0°

k = f(x/(b/2)) = 0.98

B = EVD / k ≈ EVDA=0°

B

X

CL

Ref. McCombs, William F. “Wing and Tail Dihedral for Models.”

78

AAE 451Team 3Team 3ProjectProject AvatarAvatar Dynamics

Short Period Mode

Pole -14.391 ± 1.0079i

Natural Frequency

14.431 (rad/s)

Damping Ratio

0.99721

Phugoid Mode

Pole -0.078823 ± 0.71828i

Natural Frequency

0.72259 (rad/s)

Damping Ratio

0.10908

Dutch Roll Mode

Pole -1.1607 ± 2.4427i

Natural Frequency

2.7045 (rad/s)

Damping Ratio

0.42918

Spiral Mode

Pole 0.29086

Roll Mode

Pole -25.748

Ref. Purdue University AAE565, Matlab Predator Code

STRUCTURES

80

AAE 451Team 3Team 3ProjectProject AvatarAvatar What Materials to Use

Titanium

Bass / Spruce

81

AAE 451Team 3Team 3ProjectProject AvatarAvatar Material Properties

Ref. 1999 Forest Products Laboratory Wood Handbook


Titanium = difficult to obtain

Wood = not difficult to obtain

Young's Modulus Torsional Stiffness Max Compression Stress Max Tension Stress [E] (psi) [G] (psi) [syc] (psi) [syt] (psi)

Bass 1.46E+06 2.92E+05 4730 8700Spruce 1.43E+06 2.86E+05 5180 9400

82

AAE 451Team 3Team 3ProjectProject AvatarAvatar Twist Constraint (<1o)

-1.5

-1

-0.5

0

0.5

1

1.5

0 0.5 1 1.5 2 2.5 3

X (ft)

Y (

ft)

Forward Spar

Rear Spar

Rib

Rib Cap (not shown)

Rib Rib

Chord-wise Lift Resultant

Shear Center

12

))()(()(

)Distance)(()(22

4 baseheightheightbaseinJ

ForcelbfinT

Where T = Torque (in-lbf)

L = Length (in)

l = f(B0, A0) (ref. Appendix)

A0 = f(E, I) (ref. Appendix)

B0 = f(G,J) (ref. Appendix)

E = Young’s Modulus (psi)

I = Moment of Inertia (in4)

G = Torsional Stiffness (psi)

J = Polar Moment of Inertia (in4)

Assumptions:Small Deflections

Spars & Ribs Carry all TorsionSpan ~ 14.4 ftChord ~ 2.9 ft

Safety Factor = 1.5G-Loading = 5.0Weight = 53 lbs

Ref. Kuhn pg. 49

Ref. Gere

L

L

B

TLrad

)tanh(

1)(0

83

AAE 451Team 3Team 3ProjectProject AvatarAvatar Twist at Tip

84

AAE 451Team 3Team 3ProjectProject AvatarAvatar Twist at Tip (Zoom)

Chosen Front Spar = 0.73” thick

Chosen Rear Spar = 0.25” thick

(note, this doesn’t include the step)

85

AAE 451Team 3Team 3ProjectProject AvatarAvatar Deflection at Tip

)(3))((6

))(()(

2

aLIIE

aLoadin

rearfronttip

Where Load = Weight*SF*G-loading (lbf)

L = Length (in)


I = Moment of Inertia (in4)Assumptions:

Small DeflectionsNO TORSIONSpan ~ 14.4 ftChord ~ 2.9 ft

Safety Factor = 1.5G-loading = 5.0Weight = 53 lbs

Ref. Gere pg. 892

a (in)

L (in)

Load (lbf)

For this design:

a ~ 3 ft or 36 in

(based on span-wise lift distribution)

86

AAE 451Team 3Team 3ProjectProject AvatarAvatar Deflection at Tip

Chosen Spar Configuration

87

AAE 451Team 3Team 3ProjectProject AvatarAvatar Is Stress too High?

)(

))(()(

rearfront II

yMpsi

Where M = Weight*SF*G-loading*a (in-lbf)

y = Maximum Dist from Neutral Axis (in)


Assumptions:Span ~ 14.4 ftChord ~ 2.9 ft

Safety Factor = 1.5G-loading = 5.0Weight = 53 lbs

Ref. Gere pg. 323

a (in)

L (in)

Load (lbf)

For this design:

a = 3 ft or 36 in

(based on span-wise lift distribution)

88

AAE 451Team 3Team 3ProjectProject AvatarAvatar Max Tension Stress

89

AAE 451Team 3Team 3ProjectProject AvatarAvatar Max Compression Stress

90

AAE 451Team 3Team 3ProjectProject AvatarAvatar Covering

• Traditional Monocote may not be strong enough for these large aircraft

• Coverite 21st Century Iron on Fabric is stronger, and resists tears much better– 0.34 oz/ft2

– Approx. 2 lbs for entire wing


91


• Main Wing– Spruce or Bass wood– Front Spar

• 0.73” thick by 3.6” high

– Rear Spar• 3/8” thick by 3” high

Summary

t

h

92

AAE 451Team 3Team 3ProjectProject AvatarAvatar Rear View of Tail

Downward force from H-stab creates bending moment on beams

Side force from V-stab creates torsion effect on beams

•NOTES

•Torsion can effectively be reduced with appropriate beam spacing

•Bending can be reduced by increasing moment of inertia of beams (not spacing)

•Some torsion is inherent, torsion can not be negated as it could in wing

93

AAE 451Team 3Team 3ProjectProject AvatarAvatar Deflection at Tip (Rear of Tail)

))((3

))(.)(.)(()(

3

leftrighttip IIE

LGloadingFSLoadin

Where Load = (lbf)

L = Length (in)



Assumptions:Small Deflections

Safety Factor = 1.5G-loading = 3.0

Rectangular Beams

Current Known Values:L = 6.2 ft

Load ~ 8 lbf

Ref. Gere pg. 892

L (in)

Load (lbf)

Moment of inertia of rectangular beam:

I (in4) = (t)(h3)/12

t and h shown on next slide

94


h=3 in

h=2 int

h

Green = spruce

Black = bass

95


h=3 in

h=2 in

t

h

Green = spruce

Black = bass

Required t ~0.55 in

96

AAE 451Team 3Team 3ProjectProject AvatarAvatar Landing Gear Placement (I)

Landing gear placement based on

guidelines found in Raymer

θ = tipback angle =

97

AAE 451Team 3Team 3ProjectProject AvatarAvatar Landing Gear Placement (II)

Landing gear placement based on

guidelines found in Raymer

γ = overturn angle =

98

AAE 451Team 3Team 3ProjectProject AvatarAvatar Easily Obtainable Square Tubing

Aluminum Alloy 6061

Width (in) Height (in) Thickness (in) X-Section Area P/N 1 foot 3 feet 6 feet1 1 0.125 0.5 6546K21 $6.23 $12.43 $22.33

1 1/2 1 1/2 0.125 0.75 6546K22 $9.00 $20.75 $39.00

2 2 0.125 1 6546K23 $10.50 $25.25 $48.00

Aluminum Alloy 6063

Width (in) Height (in) Thickness (in) X-Section Area P/N 1 foot 3 feet 6 feet3/4 3/4 0.125 0.375 88875K52 $2.11 $6.34 $11.091 1 0.062 0.248 88875K51 $1.57 $4.74 $11.091 1 0.125 0.5 88875K54 $3.35 $10.00 $23.39

1 1/4 1 1/4 0.125 0.625 88875K58 $3.83 $11.49 $26.771 1/2 1 1/2 0.125 0.75 88875K61 $4.10 $12.28 $28.631 3/4 1 3/4 0.125 0.875 88875K64 $4.68 $13.97 $32.59

2 2 0.125 1 88875K67 $6.03 $18.05 $42.14

Ref. www.mcmaster.com

99


Where L = Length (in)



A = Cross Sectional Area (in2)

Buckling of Rear Gear

2

2

)(L

EIlbP fcr

Assumptions:

Pinned-Pinned Column1st Mode Buckling

No Eccentricity

Ref. Gere pg. 763

For Rear Gear:

L ~ 15.3 in

Load

Load

LA

Ppsi cr

cr )(

100


Where Load = (Weight)(S.F.)(Gloading)

A = Cross Sectional Area (in2)

Compressive Failure of Rear Gear

A

Loadpsic )(

Assumptions:

Weight = 53 lbfGloading = 10

S.F. = 1.5Aluminum 6061-T6

No Buckling

Load

Load

L000,34)( psicy Ref. MIL-HDBK-5H: 3-255

101

AAE 451Team 3Team 3ProjectProject AvatarAvatar Stress on Rear Gear

t=0.062”t=0.125”

Smallest easily obtainable tubing: 1” x 1” x 0.062”

102

AAE 451Team 3Team 3ProjectProject AvatarAvatar Great, what about the bungee?

• Consider worst reasonable landing situation– Moving at (1.1)Vstall

– 5 feet above ground– Aircraft falls out of the sky

• Can the bungee absorb the energy associated with this landing?

103

AAE 451Team 3Team 3ProjectProject AvatarAvatar Great, what about the bungee?

2

2

1kxW Energybungee

PEKEEtotal

2

2

1mVKE

))()(( altitudegmPE

)()( xklbF f

•Don’t want x to exceed 3 inches (beyond initial stretch) on landing

Assumptions:

Weight = 53 lbfVstall = 30 ft/secAltitude = 5 ft

104

AAE 451Team 3Team 3ProjectProject AvatarAvatar What Spring Constant is Needed?

Required k ~ 3.75 lbf/in

1/k ~ 0.266 in/lbf

105

AAE 451Team 3Team 3ProjectProject AvatarAvatar What is the Spring Constant?

Inverse of Spring Constant versus Relaxed Length

y = 0.0152x

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

Relaxed Length (in)

1/(S

pri

ng

Co

nst

ant)

(in

/lb

f)

Relaxed Length ~18 inches

106


If load = (Weight)(S.F.)(Gloading) = 795 lbf

Reaction = 1770 lbf (instantaneous)

Need cross sectional area of bolt to be 0.197 in2

Diameter of nylon bolt = 0.5 in

How Big is the Bolt?

0moments

)Load)(6.9"()(3.1"(Reaction)

6.9”3.1”

Load

Reaction

000,9)( psinylonult

Assumptions:

Weight = 53 lbfGloading = 10

S.F. = 1.5

Ref. Gere pg 900

PERFORMANCE

108

AAE 451Team 3Team 3ProjectProject AvatarAvatar Endurance

• Endurance = Fuel / Consumptionfuel

• Avg. Engine Fuel Consumption = 45.455 mL/min

• Endurance = 30 min

109

AAE 451Team 3Team 3ProjectProject AvatarAvatar Range

R550 p

C bhp

L

D ln

W i

W f

Since this is RC, assume almost instaneous cruise conditions

L/D = 19Cbhp = 1.5 lb/hr/bhp

Prop eff = .67Fuel Frac = 1.043

110

AAE 451Team 3Team 3ProjectProject AvatarAvatar Minimum Flight Velocity

qCl

WeightVelocity

*maxmin

Velocitymin= 29.95 ft/sec

Weight = 53 lbf

CLmax = 1.19

q =1.067 lbf/ft^2

111

AAE 451Team 3Team 3ProjectProject AvatarAvatar Rate of Climb

Vv= 7.5 ft/sec

D = 6.5lbf

hpengine = 3.7 hp

W = 53 lbf

V = 33 ft/sec

Prop Eff = .3

Vv

550hpengine p

W

D VW

112

AAE 451Team 3Team 3ProjectProject AvatarAvatar Maximum Velocity

30 40 50 60 70 80 90 1000

2

4

6

8

10

12

14

16

18

20

Flying Velocity [ft/s]

Thru

st/D

rag [

lbf]

Maximum Velocity

Thrust

Drag

113

AAE 451Team 3Team 3ProjectProject AvatarAvatar Climb Angle

asinV v

V

Vv = 7.5 ft/secV = 33 ft/sec

Critical Design Review AAE451 – Team 3 Project Avatar December 9, 2003 Brian Chesko Brian Hronchek...

Documents

Transcript of Critical Design Review AAE451 – Team 3 Project Avatar December 9, 2003 Brian Chesko Brian Hronchek...