Preliminary Design Review
AAE 451 Team V
The Flying V Barn Owl
Stephen Beirne
Miles Hatem
Chris Kester
Jim Radtke
Charlie Rush
Zheng Wang
Brandon Wedde
Greg Wilson
Outline
1. Market
2. Design Requirements
3. Present Concept
4. Sizing
5. Aerodynamics
6. Performance
7. Structures
8. Weight and Balance
9. Stability
10.Propulsion
11.Cost
12.Summary
4/18/2006
AAE 451 Team V
2
GA Market Review
• Product
– 4 Seat Single Engine Piston Aircraft for Hobbyists,
Training Fleets, and Fixed Base Operators
• Powered by an Alternative Fuel
• Customer Needs
– 100LL Replacement
• Current staple fuel for GA piston engines
• Production uncertain after 2015
• Provides opportunity to be first to market
– Petroleum fuel alternative for post peak oil
4/18/2006
AAE 451 Team V
3
Design Requirements
Design Requirements Team V Plane
T/O Distance <1500 C 1499
600 lb Payload
C 600
150 kts cruise speed
C 153
600 nm range
C 600
48”x46” cabin dim.
C 50”x50”
<2800 lb GTOW
C 2705
Acq. Cost <$300k
C $298,400
4/18/2006
AAE 451 Team V
4
Current Design
The “Barn Owl”
4/18/2006
AAE 451 Team V
5
Carpet Plot
Stall (57 kts)
Wing loading vs. GTOW
3000
Cruise (150 kts)
Design Space
Climb (1300 fpm)
2900
Takeoff (1500 ft)
2800
GTOW [lbs]
Design point
Aspect Ratio
AR=10
2700
(increments of 0.5)
Turn (n=2)
2600
AR=6
2500
2400
15
Note: Sizing
was done with a
predetermined
200 hp engine
16
17
18
19
20
21
22
W/S [lbs/ft 2]
4/18/2006
AAE 451 Team V
6
I/O for Carpet Plot
Notable Outputs
Notable Inputs
GTOW = 2705 [lbs]
Cd0 = 0.026
W/S = 17.7
Payload Weight = 600 [lbs]
AR = 7.5
CL_max = 1.6
Cruise Altitude = 8000 [ft]
Takeoff (50 ft obs.) = 1499 [ft]
Power / Weight = 0.074
L/D = 10
BhpSFC = .439 [lb/hp*hr]
Sea Level Climb Rate = 1351 [fpm]
Stall Speed = 57 [kts]
Wing Area = 153 [ft2]
Turn Load Factor = 2.06
Oswald efficiency factor = 0.65
Prop Diameter = 74 [in]
Cruise Speed = 153 [kts]
Prop efficency (cruise) = 0.86
Fuel Weight = 463 [lbs]
Prop efficency (climb) = 0.76
Fuel Volume = 63 [gal]
4/18/2006
AAE 451 Team V
7
New Airfoil Design
Drag Polar
0.015
•FVGA 5121-12.1% thick
0.014
•Designed using Genetic Algorithm
0.013
•Laminar flow
0.012
•Large Laminar bucket
•Performance comparable to 2412
when tripped
0.011
•30% less drag at cruise commpared
to 2412
0.01
•Low penalty at high Cl
0.009
Cd
0.008
0.007
0.006
0.005
0.004
0.003
2412 Laminar
0.002
2412 Tripped
FVGA 5121 Laminar
0.001
FVGA 5121 Tripped
4/18/2006
-1
-0.8
0
-0.6
-0.4
-0.2
AAE 451 Team V
0
0.2
0.4
Cl
0.6
0.8
1
1.2
8
1.4
Wing Planform Design
Polynomial Twist for wing CL = 0.3
Twist Distribution for CL = 0.3
1.8
4.2
4
1.6
3.8
3.6
Twist angle (deg)
Section lift * Section cord
1.4
1.2
1
3.4
3.2
3
2.8
0.8
2.6
Wing twist distribution
Eliptical distribution
0.6
0.4
-1
0.2
y
10
15
10
15
5
-10
-5
0
5
Distance along wing
0
-10
-5
-15
-15
0
-20
20
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
Distance along span (ratio)
0.6
0.8
•Span = 33.87
•Taper ratio = 0.7
•Polynomial twist
•Close to elliptical lift distribution
•1.51 degrees total twist
-2
0
2
4/18/2006
AAE 451 Team V
9
1
Cmarc Analysis
• Used to acquire an accurate
prediction of induced drag
and parasite drag.
• Detailed fuselage shaping to
minimize interference drag
• Bathtub style wing joint
utilized, with smooth LE/TE
junctions, possible with
composite skin layover
• 8 deg tail upsweep to
minimize wake interference
4/18/2006
AAE 451 Team V
10
CD0 Determination
CD0 = 0.022 (Sref = 153)
3D Drag Polar
4/18/2006
AR = 9.6
0.4
Poly. (Barn Ow l)
Poly. (AR = 9.6)
0.35
0.3
0.25
CD
• Lower than Cessna 172
@ 0.027
• The FVGA5121 airfoil is
laminar at low CL
• Incompressible flight
envelope
• No wing struts
• Aerodynamic fuselage
• Close to elliptical
loading
Barn Ow l
0.2
0.15
0.1
0.05
0
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
CL
AAE 451 Team V
11
2.5
L/DMAX Determination
Cmarc 3D L/D vs CL
L/DMAX = 10.4
15
10
L/D
5
0
-0.75
-0.5
-0.25
0
0.25
0.5
0.75
• This is because the
FVGA5121 airfoil is laminar
at low CL
• Most efficient cruise at 185
1
ft/s (109 kts)
-5
-10
-15
CL
4/18/2006
AAE 451 Team V
12
3D Lift Curve
Lift Curve
1.2
1
0.8
CL
0.6
0.4
0.2
0
-5
-3
-1
1
3
5
7
9
11
13
15
-0.2
Alpha
Wings oriented to have a level fuselage at max cruise speed.
4/18/2006
AAE 451 Team V
13
Performance
V-n Diagram
Design Limit
Load
4
3.8 g
3
per FAR 23.337
2
n
1
FAR Gust
Velocities Under
20,000 ft
-1
50 ft/s @ VCruise
-2
0
Design Loading
25 ft/s @ VDive
Gust Loading
-3
4/18/2006
0
20
40
60
AAE 451 Team V
80
100
Ve [Knots]
120
140
160
14
Performance
4/18/2006
AAE 451 Team V
15
Structure
• Material Selection
– Aluminum frame with fiberglass skin selected
– Cost savings expected
– Slight weight savings achieved
• Frame
– “Big bones” approach
– Manufacturing cost reduced due to fewer components
and advanced joining
• Skin
– Fiberglass cured in large segments
– Segments bonded to frame
4/18/2006
AAE 451 Team V
16
Structural Layout
I-Beam Spar
C-Channels
Ribs
4/18/2006
AAE 451 Team V
17
Spar Carrythrough
• Spar located at
front of rear
seats
• Spar does not
hinder cabin
comfort
4/18/2006
AAE 451 Team V
18
Component Weights
• Began with Raymer’s
Statistical Group
Weights method
• Replaced with known
or calculated weights
–
–
–
–
Engine
Propeller
Wings
Fuselage
4/18/2006
AAE 451 Team V
19
Component Weights
• Engine
– Total installed weight from DeltaHawk
– Includes all pumps, turbocharger, lines,
exhaust, and mount
– 390 lbs
• Propeller
– Off the Shelf
– 51 lbs
4/18/2006
AAE 451 Team V
20
20
Wing Sizing
• Cross-sectional optimization along span
• Design Variables:
Skin Thickness
Spar Web Thickness
Spar Cap Size
Stringer Area
Spar Cap Thickness
Rib Spacing
• Constrained by:
4/18/2006
Allowable Stresses
Upper Skin Buckling
Spar Web Buckling
Damage Tolerance
AAE 451 Team V
21
Wing Sizing
• Validation of sizing algorithm
– Raymer statistical weight:
– All-aluminum wing optimization:
302 lbs
300 lbs
• Our design
– S2-glass/epoxy skin
– New weight:
286 lbs
– Difference due to minimum gauge skin over
outer 1/3 span
4/18/2006
AAE 451 Team V
22
Fuselage
• Preliminary model created and analyzed
with I-DEAS
• Ability to sustain limit load verified
4/18/2006
AAE 451 Team V
23
Weight and Balance
Component
Dist. from nose [in.] Weight [lbs]
Engine
30
390
Prop/Spinner
6
51
Avionics
81
51
Fuel System
123
47
Electrical System
60
130
Wing
129
286
Flight Controls
160
41
Hydraulics
138
3
fuel
123
463
Front Seat PAX
106
300
Rear Seat PAX
143
300
Furnishings
125
92
Fuselage
160
241
Horiz Tail
321
98
Vert Tail
321
21
Main Gear
138
151
Nose Gear
44
29
Total Weight
Center of mass
4/18/2006
2694 lbs
117 in. from nose
AAE 451 Team V
• Design gross
weight from
sizing
– 2705 lbs
• Detailed gross
weight
prediction
– 2694 lbs
24
C.G. and Static Stability
• Static Margin with full load
• Static Margin with no fuel, 1 pilot
CG Travel
20% S.M.
10% S.M.
3000
C
E
2500
D
Weight
2000
F
1500
10.6%
19.6%
B
G
A
H
1000
A
B
C
D
E
F
G
H
Empty Fuel, Rear PAX
Full Fuel, Rear PAX
Full Fuel, all PAX
Full Fuel
Full Fuel, Front PAX
Empty Fuel, 2 Front PAX
Empty Fuel, 1 Front PAX
Empty
500
0
109
111
113
115
117
119
CG position (in)
4/18/2006
AAE 451 Team V
25
Fuel Selection
• Bio-diesel chosen as alternative fuel
• Reasons chosen:
– BSFC of 0.439 lbs/(hp*hr) is bested only by
hydrogen
– Most developed technology of all of the
proposed alternative fuels
– Requires only minor modifications to
available piston engines
4/18/2006
AAE 451 Team V
26
Engine Design
• Engine Requirements:
– No more than 200 hp to remain “low
performance”
– Meet dimension constraints for the nose of
the aircraft
– Powerful enough to meet cruise speed target
• An existing diesel aircraft engine meets
our requirements
– Development cost savings
4/18/2006
AAE 451 Team V
27
Engine Design
• Deltahawk V4 DH200V4
• Rated Power
– 200 hp
• Total installed Weight
– 390 lbs
• Dimensions:
– 30x23x32 (inches)
• Cost
– $32,450
• Meets all desired
requirements
4/18/2006
AAE 451 Team V
28
Propeller
• Existing Propeller
– 2 Blade, constant Speed
– Hartzell HC-C2YK-1 ( )/7666A-2
• Same Propeller as Piper Arrow
– HP 200
– RPM 2700
– Cruise 145 kts
• Specs.
– Max constant HP = 250
– Max constant RPM = 2700
– Diameter = 74”
4/18/2006
AAE 451 Team V
29
Acquisition Cost
• Three cost estimating relationships:
– GA Plane Library
– Modified RAND DAPCA
– Airframe Weight Relationship
• Weighted average yields purchase price of
~$298,400.00
• RTD&E Break-Even set by DAPCA model at ~5
years (~2000 planes)
– Reasonable with market that breakeven would be
met.
4/18/2006
AAE 451 Team V
30
Acquisition Cost
Purchase Price v DAPCA CER v AMPR CER
$700,000.00
$600,000.00
Purchase Price
AMPR ($277.05/lb)
DAPCA*60%
Acquisition Cost
$500,000.00
Expon. (AMPR)
Expon. (DAPCA)
$400,000.00
Expon. (Purchase Price)
$300,000.00
$200,000.00
$100,000.00
Barn Owl
$1500
2000
2500
3000
3500
4000
GTOW (lbs)
4/18/2006
AAE 451 Team V
31
Operating Costs
• Compiled data from web resources
(Company websites; Plane Quest)
• Allows for current fuel prices
– 100LL ~ $4.27/gal
– B100 ~ $3.00 - $3.25/gal
• Gives Total Operating Cost of ~$81/hr
(2006 USD) 
4/18/2006
AAE 451 Team V
32
Operating Costs
Operating Costs v. GTOW
$180.00
Variable DOC/hr
Fixed DOC/hr
Total Operating Costs/hr
Barn Owl (GTOW)
Expon. (Total Operating Costs/hr)
Expon. (Variable DOC/hr)
Expon. (Fixed DOC/hr)
$160.00
Operating Costs
$140.00
$120.00
R2 = 0.8677
R2 = 0.9155
$100.00
$80.00
$60.00
R2 = 0.6407
$40.00
$20.00
Barn Owl
$1500
2000
2500
3000
3500
4000
GTOW (lbs)
4/18/2006
AAE 451 Team V
33
Operating Costs
• How does ~$81/hr compare?
Plane Type
DOC/hr variable
DOC/hr fixed
Total Cost/Hr
Diamond DA 40
$
55.00
$
15.00
$
70.00
Flying V Barn Owl
$
55.00
$
26.00
$
81.00
Cessna 172S
$
64.00
$
26.00
$
90.00
Cessna 182s
$
87.00
$
44.00
$
131.00
Cirrus SR 22*
$
99.00
$
41.00
$
141.00
*Determined using DOC v. GTOW Relationship
4/18/2006
AAE 451 Team V
34
Life Cycle Cost Estimate
• Est. Cost for Owner over 12 year span of time?
Purchase Price
$
298,400.00
RTD&E/unit
$
53,712.00
~20% purch./1.1
Production/unit
$
217,832.00
~80% purch./1.1
$
767,426.67
~500 FH/yr.
Fuel
$
234,000.00
B100=$3/gal; 13 gal/FH
Maintenance
$
240,000.00
MMH/FH=0.5; $/MMH=80.00
Insurance
$
24,866.67
Depreciation {f(age)}
$
268,560.00
Disposal
$
(29,840.00)
Life Cycle Cost
$
1,035,986.67
O&M (total over yrs.)
Notes:
~0.7% purch price/year
(purch/12 *age), for age <12
• Saves Owner over $100,000 than if same plane were
powered by 100LL at current prices! (LCC $1,136k)
4/18/2006
AAE 451 Team V
35
Design Requirements
Design Requirements Team V Plane
T/O Distance <1500 C 1499
600 lb Payload
C 600
150 kts cruise speed
C 153
600 nm range
C 600
48”x46” cabin dim.
C 50”x50”
<2800 lb GTOW
C 2705
Acq. Cost <$300k
C $298,400
4/18/2006
AAE 451 Team V
36
Range
Range
Range
Range
Range
Range
4/18/2006
@
@
@
@
@
@
45% power (nm)
55% power (nm)
60% power (nm)
75% power (nm)
80% power (nm)
88% power (nm)
VA
irc
ra f
t
Te
am
Cir
rus
SR
-2 2
A-4
0
Dia
m
on
dD
18
2T
Ce
ss
na
18
2
Ce
ss
na
Ce
ss
na
Ce
ss
na
17
2
17
2S
P
Comparison to Current
Competition
687
580
-
638
518
-
930
773
-
971
615
-
600
-
700
-
600
-
Power (bhp)
Power loading (lbs/hp)
Climb at sea level (fpm)
Cruise speed (kts)
Stall speed, flap up (kts)
Balanced field length (ft)
160
15.3
720
122
47
1685
180
14.2
730
124
48
1630
230
13.5
924
145
49
1514
235
13.2
1040
159
49
1385
180
14.1
1070
147
49
1027
310
10.9
1304
185
61
1574
200
13.5
1351
153
57
1499
GTOW (lbs)
Usefull load (lbs)
Wing area (sf)
Wing loading (lbs/sf)
2457
818
174
14.1
2558
895
174
14.7
3100
1140
174
17.8
3112
1037
174
17.8
2535
906
145
14.5
3400
1150
145
23.4
2705
1063
153
17.7
Purchase Price ($)
$172k
$180k
$326k
$355k
$259k
$350k
$298k
AAE 451 Team V
37
Summary
• The Barn Owl will be a successful alternative
fuel aircraft
• The current design is feasible and meets all
requirements
• Next steps:
– Controls sizing & dynamic stability
– Refine and consolidate structure, aerodynamic, and
layout models
– Detailed production cost estimation
4/18/2006
AAE 451 Team V
38
This Concludes the…
Preliminary Design Review
AAE 451 Team V
Stephen Beirne
Miles Hatem
Chris Kester
Jim Radtke
The Flying V Barn Owl
Charlie Rush
Zheng Wang
Brandon Wedde
Greg Wilson
Slide left intentionally blank… except for this.
4/18/2006
AAE 451 Team V
40
References
• Hartzell Propeller Data. “TYPE CERTIFICATE DATA SHEET NO. P-920
Available
<http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgM
akeModel.nsf/0/aac7773a13ad299186257114005a5cd0/$FILE/P920.pdf>.
• Plane Quest. Plane Quest Website. Cited 4/1/06. Available
<http://www.planequest.com/operationcosts/default.asp>.
• Raymer, Daniel. Aircraft Design a Conceptual Approach. 3rd Ed. 1999.
AIAA. Reston, VA.
4/18/2006
AAE 451 Team V
41
CFD
4/18/2006
AAE 451 Team V
42
CFD
4/18/2006
AAE 451 Team V
43
Wing Structure Sizing Results
Spar Web Thickness
0.14
0.13
Thickness [in]
0.12
0.11
0.1
0.09
0.08
0.07
0.06
0.05
0.04
0
50
100
150
200
Span location [in]
4/18/2006
AAE 451 Team V
44
Wing Structure Sizing Results
Spar Cap Thickness
1.1
1
0.9
Thickness [in]
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
50
100
150
200
Span location [in]
4/18/2006
AAE 451 Team V
45
Wing Structure Sizing Results
Spar Cap Width
1.7
1.6
Width [in]
1.5
1.4
1.3
1.2
1.1
1
0
50
100
150
200
Span location [in]
4/18/2006
AAE 451 Team V
46
Wing Structure Sizing Results
Skin Thickness
0.09
Thickness [in]
0.08
0.07
0.06
0.05
0.04
0.03
0
50
100
150
200
Span location [in]
4/18/2006
AAE 451 Team V
47
Wing Structure Sizing Results
Stringer Area (of each stringer)
0.16
0.14
Area [in2]
0.12
0.1
0.08
0.06
0.04
0.02
0
0
50
100
150
200
Span location [in]
4/18/2006
AAE 451 Team V
48
Propeller
Parameter
density
speed of sound (a)
a * .85
Two Bladed Propeller?
V= Forward Velocity
Value
2.38E-03
1116.40
948.94
Units
slug/ft^3
ft/s
ft/s
yes --
Parameter
V_tip
V_tip_helix
200.00 lb-f^2/s^3
D=Drag
T=Thrust
630.67 lb-ft/s^2
630.67 lb-ft/s^2
2700.00 1/min
45.00 1/s
Notes
must be less than (a*.85
must be less than (a*.85
Advance Ratio
0.91 --
Power Coefficient
Thrust Coefficient
Speed-Power Coefficient
0.06 -0.13 -3.39 --
Raymer 13.13
Raymer 13.14
Activity Factor per blade
106.4 --
Raymer 13.15
Two Blade Diameter
6.17
74.04
5.64
67.69
Raymer 10.23
Three Blade Diameter
ft
in
ft
in
Raymer 10.24
Delta Hawk website
Tip Ground Clearance
Minimum Tip Clearance
Cruise Efficiency
TO/Land Efficiency
0.86 -0.70 --
Shaft Ground Clearance
4.20 ft
Propeller lambda
0.80 --
Crossley says ~.8
~.85
~.7 for fixed
0.50 ft
guess
4/18/2006
root chord of prop.
Value
Units
872.26 fps
908.26 fps
yes or no (no->b= 3)
150.00 kts
172.62 smi/h
253.17 ft/s
SBHP=
N=RPM
Notes
h=0
h=0
h=0
Forward Flight Thrust
Static Thrust
AAE 451 Team V
1.12 ft
0.00 ft
random parameter?
630.67 lb-ft/s^2 Raymer 13.17
987.38 lb-ft/s^2
49
Two and Three Blades
80
79
78
Diameter (in)
77
Propeller
76
Two Blades
Three Blades
75
74
73
72
Barn Owl
71
70
2350
Two and Three Blades
2400
2450
2500
2550
2600
2650
2700
2750
RPM
90
85
Two Blades
R: Two Blade
Three Blades
R: Three Blades
Diameter (in)
80
75
70
65
Barn Owl
60
4/18/2006
100
120
140
160
180
200
220
HP
240
260
AAE
280 451
300Team
320 V
340
50