Optimization of
Internal Wing Aircraft (IWA)
Australian Diamond (AD1)
Brian Zabovnik
AME 5740
28 April 2008
Contents
1) Preliminary Analysis
2) Taguchi Design Parameters
3) Simulation Data
4) Analysis Results
Preliminary Analysis
• Design Constraints
– The airfoil was chosen as a Clark Y
• Efficient for small UAV aircraft
• Provides a relatively high L/D Ratio for a short wing span
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The fuselage style of the AD1 would be fixed
Root and tip chord of each wing is a fixed value
Wing Span is a fixed dimension (~1.46 meters)
Length is a fixed dimension (~1.62meters)
AD1 will weigh approx 16 lbs (71 N)
• Variable Parameters
– Pitch of each Coanda, TOD and Wing will all be
variable
– Angle of Attack of the Aircraft will be variable
Justification for Simplistic
Simulation
• The simulations were run as a half model with a
relatively low resolution
– This takes about ¼ of the time to compute, but is it
accurate?
• Simulations for full & half-model were compared
– Percent difference in L/D Ratio was 0.32% in favor of
the full model
– Lateral force for the half-model was the reason for the
difference
• Simulations for a high resolution were compared
– Comparisons between the high resolution (approx
900k cells) and low resolution (approx 200k cells) had
showed a difference of 1.1% in L/D ratios in favor of
the low resolution
Taguchi Design Parameters
• Controllable Variables
– Angle of Attack (AOA) of aircraft
– Pitch of Coanda
– Pitch of Top of Duct (TOD)
– Pitch of Wing
• Noise Variables
– Resolution Setting
– Input Velocity
– Symmetric Flow
Taguchi Analysis and Results
Angle of Attack for Aircraft
Best AOA
0 deg
SN Ratio
15.20
14.80
14.40
14.00
0
1
2
3
4
Level
Pitch of Coanda
Best Pitch
0 deg
SN Ratio
18.00
16.00
14.00
12.00
0
1
2
3
4
3
4
Pitch Level
SN Ratio
Pitch of Wing
Best Pitch
3 deg
15.20
14.80
14.40
14.00
13.60
0
1
2
Level
Pitch of TOD
Best Pitch
0 deg
SN Ratio
15.20
14.80
14.40
14.00
0
1
2
Level
3
4
Australian Diamond (AD1)
Analysis Results
• Aerodynamic Parameters that we Identified
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Aspect Ratio: AR = 0.905
Induced Drag Constant: K = 0.481
Oswald Efficiency: e = 0.732
Static Margin, Aircraft Stability: SM = -2.54
Zero Lift Angle of Attack, αL=0 = -9.4°
Zero Lift Drag Coefficient. CDO = 0.0123 (123 drag counts)
Zero Lift Moment Coefficient, Cmo = 0.0364
• Indicates that aircraft is almost at trim at 0 AOA flight
– Lift to Drag Ratio at Zero AOA: L/D = 7.43
– Maximum Lift Produced: L = 1622 N @15 deg AOA
• More than 23 times the aircraft weight!
Analysis Results
• Significant Velocities (AD1 at 16lbs)
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Max Vel.
119 mph (53.19 m/s)
Stall Vel.
26 mph (11.62 m/s)
Max Range Vel.
55 mph (24.58 m/s)
Max Endurance Vel. 40 mph (17.88 m/s)
• Other Significant Information
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Max Climb Rate
21.9 mph (9.81 m/s)
Max Climb Angle
33.2 deg
Glide Range at 10,000ft is approx. 13.8 miles
Glide Endurance at 10,000 ft is approx. 21 minutes
Graphs
0.08
0.6
Re=9.7E4
Re=1.9E5
Re=3.9E5
Re=4.7E5
0.2
0
0.00
-0.2
0.05
0.10
0.15
0.20
0.25
0.30
-0.4
C m = -2.5397*C L + 0.4038
-0.6
2
R = 0.9933
0.35
D)
0.07
0.40
0.45
Coefficent of Drag (C
Moment Coefficent (Cm)
0.4
0.06
0.05
0.04
Coefficent of Lift (CL)
2
0.03
C D = 0.4808*C L + 0.0123
0.02
R = 0.9891
2
0.01
0.00
0.00
-0.8
Re=9.7E4
Re=1.9E5
Re=3.9E5
Re=4.7E5
0.02
0.04
0.06
0.08
0.10
2
Coefficent of Lift Squared (CL )
0.12
0.14
Conclusions
• The AD1 Concept shows a strong potential to be
a heavy lifting UAV
• Taguchi Results were close to the ideal wing
configuration but more refinement is needed
• Aircraft is very stable and produces lots of lift for
its small Aspect Ratio (AR)
• The concept has plenty of room for improvement
• Next parameters to be studied are the effects of
changing the wing location and eventually the
wing profiles
Questions?