Project Presentation Boiler Xpress December 5, 2000 Team Members Oneeb Bhutta Matthew Basiletti Ryan Beech Micheal Van Meter AAE 451 Aircraft Design.

Project Presentation Boiler Xpress December 5, 2000

Team Members Oneeb Bhutta Matthew Basiletti Ryan Beech Micheal Van Meter

AAE 451 Aircraft Design

Presentation Overview Design Mission Concept Selection & Initial Sizing Detailed Analysis:

Aerodynamics Structures Propulsion Stability, Dynamics, and Control

Conclusions

The Mission

Variable Stability Aircraft- Roll Axis 1.2 lb payload

Flight Within Mollenkopf Athletic Ctr: 20 ft/s stall speed 12 minute Endurance/ electric power

plant Robust and Affordable Transportable Airframe cost < $200

Flight Mission

5.5 deg Climb Angle

35 ft Radius

120 ft. max T.O. roll

10 second “Straight Line”

42’ Ceiling height

1

2 3

4

5

ObjectiveScore % of

TotalRank

Endurance 30 10.0 7

Build within 3 weeks

10.0 9.16 4

Light weight 27.5 16.66 1

Turning radius 9.16 16.66 2

Robustness 50 10 6

Transportability 16.66 4 9

Ease of analysis 50 7.5 8

Landing ability 16.66 2.66 10

Maintainability 30 10 5

Marketability 10 13.33 3

Weighted Objectives Method

Constraint Diagram

Initial Sizing Electric Models wing area vs weight

0

200

400

600

800

1000

1200

1400

1600

1800

0 50 100 150 200 250 300 350 400

Weight (oz)

win

g a

rea

(sq

.in

.)

Geometry and Configuration

Wing:•Sref = 13.5 sq.ft.•Span = 11 ft.•Aspect Ratio = 9•Taper Ratio = 0.6 tip section•Airfoil: S1220

Horizontal Stabilizer:•Area = 1.83 sq ft.•Span = 3.0 ft.

Vertical Stabilizer:•Total Area: 1.15 sq.ft.

Boiler Xpress 11.1’

5.8’

Aerodynamic Design Issues

Lift

• Low Reynolds Number Regime

• Slow Flight Requirements

Drag

• Power Requirements

• Accurate Performance Predications

Stability and Control

• Trimmability

• Roll Rate Derivatives

Low Reynolds Number Challenges

•Laminar Flow -more Prone to Separation

•Airfoil Sections designed for Full-sized Aircraft don’t work well for below Rn=800,000

•Our Aircraft Rn=100,000-250,000

Separation Bubble-to be avoided!

Airfoil Selection

Wing:Selig S1210

CLmax = 1.53 Incidence= 3 deg

Tail sections:flat plate for Low ReIncidence = -5 deg

Re = 150e3

0

0.01

0.02

0.03

0.04

0.05

0.06

-0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2

Cl

Cd

FX63-137

S1210

S1223

Drag Prediction Assume Parabolic Drag Polar

2

0 LDD KCCC

AeK

1

75.0e Based on Empirical Fit of Existing Aircraft

Parasite Drag

ref

wetfDo S

QFFSCC

(Ref. Raymer eq.12.27 & eq.12.30)

58.2(Re)10log

455.02.1fC

Drag Build-up Method of Raymer

Blasius’ Turbulent Flat Plate- Adjusted for Assumed Surface Roughness

Drag Polar

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.80

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

Aircraft Drag Polar

CL

CD CDiCDo

Power Required

15 20 25 30 35 4016

18

20

22

24

26

28

30

32

Velocity [ft/s]

Po

wer

Req

uir

ed [

ft-l

b/s

]

Predict:• Power required for cruise

• Battery energy for cruise

Aerodynamic Properties

Wetted area = 44.5 sq.ft.Span Efficiency Factor = 0.75CL=5.3 / rad

CL e = 0.4749 /radL/Dmax = 15.5Vloiter = 24 ft/sCLmax = 1.53CLcruise = 1.05Xcg = 0.10-0.38 (% MAC)Static Margin = 0.12 at Xcg = 0.35

Stability Diagram

elev deflect=-8 deg

-4

0

4

8

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

CL

Cm

cg

elev deflect=-8 deg

-4

0

4

8

Flow Simulation

Parasite Drag CDo for Wing and Tail surfaces

18.04

34.11006.01 Mct

cx

ct

FFWing

d

lf

400100

601

3

f

fFFFuselagef

FFPOD

35.01

(Ref. Raymer eq.12.31 & eq.12.33)

For Fuselage, booms & pods

Structures Outline

Materials Employed for the structure Mathematical Model Bending Moment & Stresses; Wing Test Equipment layout Landing Gears & Landing Loads

Structural Materials

Styrene foam wing core

Balsa spars carry bending load 0.25 in x 0.25 in

T.E. Reinforcement

Materials Employed

Wing

Mathematical Model

Wing

Assumptions:•Wing and Weight loading•Method of Analysis (Theoretical Model)•2.5g x 1.5 P

Boom

Horizontal Tail

Bending Moments

Max Moment = 41.71 lbf/ft

Stresses in Wing

Sigmamax = 2003 psi

Sigmacritical = 1725 psi (Actual Test Result; Whiskey Tango Team, Spring 1999)

Reasons: Light Weight Structure Safety Factor (worst case scenario) Wing Test Results

I

yM maxmax

1.5ft

P

Horizontal Tail & Boom Horizontal Tail:

Max Stress = 850psiSpar Sizes = 1/8 in x 1/16in

Booms:Max deflection = 0.24 in @ 2.5g’s x 1.5 Assuming Young Modulus (E) for a Carbon Epoxy matrix.Testing needed to verify result.Material & Time Constraint

Equipment Layout & CG.

CG. = 30%~38% MAC (Predicted)

CG. = 35% MAC (Actual)

Landing Gear

From Raymer. Method of Sizing and placement of Landing gears

Rotation angle = 10 deg

Tip Back angle= 14 deg

Nose Gear: (3’’ from nose)

Main gears:

-6’’ from leading Edge

-Separation (1.5 ft)

Vland=1.3Vstall=25ft/s

lbinVKe vertgW 6.72

21

kkSdsWorkd

5.00

For d = 1 in., k = 15.2 lb/in

= -5 degVvert=2.2ft/s

For 1 inch strut travel, peak load = 15.2 lb

spar = 240 psi on landing

Landing Loads

Propulsion Design Issues Power Special needs Endurance Propulsion system tests

Power

Power required is determined by aircraftPower available comes from the motor 15 20 25 30 35 40 45 50

15

20

25

30

35

40

45

50

55

Velocity [ft/s]

Pow

er R

equi

red

[ft-

lb/s

]

Power Required Power Available

Special Needs

Pusher configurationAdjustable timing motorReversible motor

PropellerHigh efficiency for enduranceSpecial propeller for electric flight

System Components

PropellerFreudenthaler 16x15 and 14x8 folding

Gearbox“MonsterBox” (6:1,7:1,9.6:1)

MotorTurbo 10 GT (10 cells)

Speed ControllerMX-50

System EfficienciesPropeller

60-65%

Gearbox95%

Motor90%

Speed Controller95%

Total System Efficiency

50.7%

Propulsion TestsBoiler Xpress Propulsion system Tests

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0:00:00 0:02:53 0:05:46 0:08:38 0:11:31 0:14:24 0:17:17

Time (h:mm:ss)

Th

rust

(lb

)

Static

Test1

Test2

Test3

Test4

Endurance

Torque Sensor

Motor/Prop

To Batteries

Test Stand Attached to Wind Tunnel Balance

Aircraft Analysis

Best Endurance SpeedVe = 23.2 ft/s

Power Required at Best Endurance SpeedPr = 15.62 ft-lb/s

Flight Performance

Increased weight17% increase

Increased cruise flight speed22% increase

Lift coefficient26% decrease

Endurance/Power42% decrease in endurance

Flight Performance, Stability & Control Sizing of horizontal and vertical tails

and control surfaces Location of c.g. and aerodynamic

center Determination of static margin Roll-axis block diagram Transfer functions Flight Performance Data

Horizontal and Vertical Tail Initial Sizing

v

refvv x

bSVS

h

refhh x

cSVS

Vh - Horizontal tail volume coefficient = 0.50Vv - Vertical tail volume coefficient = 0.044

(8.3) (8.4)

Control Surface Sizing

Based on historical data from Roskam Part II Tables 8.1 and 8.2.

ref

a

S

S

v

r

S

S

h

e

S

S

Homebuilts Single Engine

0.095 0.08

0.42 0.36

0.44 0.42

235.1 ftSa

280.0 ftSr

200.1 ftSe

Dihedral Angle Paper by William McCombs

suggests 0 – 2 degrees for RC aircraft with

ailerons. Estimated by Raymer for a mid-

wing aircraft to be 2 – 4 degrees. Our Aircraft- 2 degrees

X-plot Horizontal Tail

1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Horizontal tail area [sq ft]

x/c

cg location neutral point

Xac = 0.46

Xcg = 0.35

SM = 11% MAC

cgac XXSM

-Used to find elevator area for desired Static Margin

X-plot Vertical Tail

0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

-0.4

-0.2

0

0.2

0.4

0.6

Vertical tail area [sq ft]

CnB

eta

Used to determine Weathercock stability (yaw)

Cn = 0.11

Flight Performance

Calculated MeasuredTake-off Distance (ft) 56.7 70 (astroturf)Turn Radius (ft) 50 < 40Cruise Speed (ft/s) 24 28Endurance (sec) 720 730

Tx

Rx 1

k

/

+ aP

Block Diagram – Roll Axis

85.76

31.62

s

95040

9502 ss

Servo Aircraf

t

Gyro

Dynamic Modeling

85.76

31.62

)(

)(

ss

sP

a

xx

l

I

qSbCL a

a

1

2

2 UI

CqSbL

xx

l

pp

p

a

l

l

C

C= 0.80

= -0.15

s

rad

2s

rad

Root Locus

-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20-80

-60

-40

-20

0

20

40

60

80

Real Axis

Imag

Axi

s

De-stabilizing feedback

Nyquist Diagram

Real Axis

Imag

inar

y A

xis

Nyquist Diagrams

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3From: U(1)

To

: Y(1

)

K = 0.3655

Gm=25.4284

Pm=inf.

Economics

Man-hours per week Structural Cost Break-Up Propulsion & Electronic Equipment

Cost Total Cost of the project

Man-Hours

BoilerXpress Man hours per Week

0

50

100

150

200

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Number of Weeks

To

tal

Te

am

Ho

urs

Structural Cost

Glue23%

Balsa7%

Micafilm13%

foam12%

fiber glass3%

Carbon fiber booms22%

wires9%

others11%

Cost = $292.00

Structural Cost Break-UpStructural CostComp. Cat. # Description Qty. Price/unit subtotal

CST A105-A 105 resin 1 $23.70 $23.70CST A206-A Slow Hardener (5:1) 2 $11.40 $22.80CST S-G01040-38 Fiberglass 0.5 oz/sq-yd. (2 yards) 1 $10.00 $10.00

Tower LXAS81 5510 Lite Ply 1/8"x6"x12" (6) 1 $12.59 $12.59Tower LXB243 yellow Micafilm 65" (rolls) 1 $9.99 $9.99Tower LXB247 yellow Micafilm 15' (rolls) 1 $26.99 $26.99Tower LXD867  Dubro Threaded Rod 2-56x12" (6) 1 $2.39 $2.39Tower LXD882  Dubro Nylon Kwik-Link Standard (2) 3 $0.70 $2.10Tower LXJC94 1/4"x3"x36" Balsa - 8pcs 1 $7.99 $7.99Tower LXNK03 Motor Wire (black) 2 $6.49 $12.98Tower LXNK04 Motor Wire (red) 2 $6.49 $12.98Lowes Blue or Pink Foam (4'x8' sheets) 2 $17.00 $34.00

epoxy glue 1 $20.00 $20.00Carbon fiber 1/2" x .032" x 60 " tubes for booms 2 $32.75 $65.50screws and fasteners 1 $15.00 $15.00Purdue University Stickers 2 $4.99 $9.98spray paint 1 $3.00 $3.00

Total $291.99

Motor & Electronic Equipment

Propulsion & Electronic Equipment Cost

Comp. Cat. # Description Qty. Price/unit subtotalHobby HLAN241 1/4" Prop Shaft Adapter 1 $1.00 $1.00Hobby HLAN3168 14x8 Prop Blade 1 $13.40 $13.40Hobby HLAN3186 16x15 Prop Blade 1 $15.30 $15.30Hobby HLAN4223 47mm Middlepart Yoke 1 $12.00 $12.00Hobby HLAN5145 45mm Spinner 1 $5.00 $5.00MEC Motor Power Package 1 $200.00 $200.00

$246.70Radio Control System (transmitter, receiver etc.) 1 $250.00 $250.00Battery packs 1 $70.00 $70.00Battery charger 1 $100.00 $100.00

Tower LXTX41  Hitec/RCD HS-55J Economy Sub Micro Servo Futaba2 $19.99 $39.98Rate Gyroscope 1 $109.00 $109.00

$568.98

Total $815.68

Propulsion

Electrical Equipment

Total CostMan-Hour Breakup

Rate = $75/hour

hours CostPreliminary Design 525 $39,375.00

Testing 50 $3,750.00Build 720 $54,000.00

Test Material $81.70Structural Cost $291.99

Prop and Elec Cost $815.68Total Cost $98,314.37

ConclusionsFlight performance requirements met

Turn radiusEnduranceTake-off distance

Stabilizing feedback implementedFuture Work

Data logger installationImplement destabilizing feedbackRefine propulsion analysis method (further testing)Perfect construction method

Questions?