AAE 451 Aircraft Design

Critical Design ReviewBolierXpress

Team MembersOneeb Bhutta, Matthew Basiletti , Ryan Beech, Mike Van

Meter

11ft

6ft

3-D Views

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

Tail GeometryHorizontal Tail:Area = 2.2Span = 3.0ft Chord = 0.73ftVh = 0.50

Sc

Sxv hh

h

Vertical Tail- 25% added

Area = 1.75 sq.ftSpan = 1.63 ft Chord = 0.60 ftVv = 0. 044

Sb

SXV vv

v

Control Surface Sizing:Elevator

Area Ratio = 0.30 Chord = 2.7 in.

Rudder Area Ratio = 0.40

Single rudder of chord = 7.5 in.

AileronsArea Ratio = 0.10Aileron chord = 3 in.

Equipment Layout & CG.

Rotation angle = 10deg

Tip Back angle= 15deg

Controls equipmentPropulsion componentAirframe component

17.54 in.

Miscellaneous Weight

Equipment Layout (3-D)

Landing Loads

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

Static Margin, Aerodynamic Center, and c.g.

Xac = 0.46

Xcg = 0.35

SM = 0.11

cgac XXSM

Horizontal and Vertical Tail Sizing

v

refvv x

bSVS

h

refhh x

cSVS

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

22.2 ftSh 275.1 ftSv

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

Control Surface Sizing (cont.) Sa = 1.35ft2

Sr = 0.80ft2

Se = 1.00ft2

Max. surface deflection is 15 deg.

Climb Performance Max. Climb Angle, G

W

DT1sin

G = 7.3 deg.

Turning Performance Maximum turn rater = 50ft

Vmax = 28ft/s

Y= 0.28 rad/s

Propulsion Design Issues

PowerPower requiredPower available

EnduranceCan we complete the mission

VerificationMotor test to take place this week

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

System EfficienciesPropeller

60-65%

Gearbox95%

Motor90%

Speed Controller95%

Total System Efficiency

50.7%

System Components

PropellerFreudenthaler 16x15 and 14x8 folding

Gearbox“MonsterBox” (6:1,7:1,9.6:1)

MotorTurbo 10 GT (10 cells)

Speed ControllerMX-50

Economics

Preliminary Design525 man-hours @ $75 = $39,375

Testing50 man-hours @ $75 = $3,750$81.70 in materials

Economics

Prototype Manufacturing300 man-hours @ $75 = $22,500$417.35 in materials

Flight Testing$900

Prototype manufacturing budget$200 max

The Budget

Total Project Cost The Bottom Line

$67,024.05

Questions?