1. PROPULSION PDR 2 AAE 451 TEAM 4
Jared Hutter, Andrew Faust, Matt Bagg, Tony Bradford,
Arun Padmanabhan, Gerald Lo, Kelvin Seah
November 11, 2003

2. CONCEPT REVIEW Empennage High Wing Twin Booms Twin Engine Avionics Pod
S = 47.8 ft2
b = 15.5 ft, c = 3.1 ft
AR = 5
Twin Booms
3 ft apart;
7.3 ft from Wing MAC to HT MAC
Twin Engine
1.8 HP each
Avionics Pod
20 lb; can be positioned front or aft depending on requirements
Empennage
Horizontal and Vertical Tails sized using modified Class 1 Approach
(per D & C QDR 1)

3. OVERVIEW Engine Selection & Endurance
Propeller Selection, Analysis & Choice
Twin Engine Performance
Follow-Up Actions

4. Propeller Efficiency of 45% used
CONSTRAINT DIAGRAM showing only relevant constraints for single engine operation
Propeller Efficiency of 45% used

5. ROADMAP TO ENGINE SELECTION
Calculations based on single-engine flight
From the Constraint Analysis,
Power Loading, W/P = 46 lbf / SHP
From Current Weight Estimate,
Gross Take-Off Weight, WTO = 54.5 lbf
Total Required Power = 1.2 HP

6. ENGINE CHOICE Engine Choice: Saito FA-100 Specifications:
Weight: 20.8 oz
Bore: 29.0 mm
Stroke: 26.0 mm
Displacement: 1.0 cu. in.
Practical RPM: 2, ,500
Power: 1.8 ~9200 RPM
Fuel Consumption Rate: 1 oz/min
$279.99
at maximum RPM
Source:

7. DRAG ANALYSIS & REQUIRED THRUST
Span efficiency, e 0.6
Aspect Ratio, AR 5
Lift Coefficient, CL 1.03
Induced Drag Coefficient, CDi
Parasitic Drag Coefficient, CD
Drag Coefficient, CD = CD0 + CDi
Wing Area, S ft2
Velocity = 1.2 Vstall = 1.2 28 ft/sec = 33.6 ft/sec
Density, ρ = slug/ft3
Drag = 10.4 lbf

8. DRAG ANALYSIS & REQUIRED THRUST (continued)
Drag = 10.4 lbf
Flight Path Angle,  = 0.5
Weight = 54.5 lbf
Thrust = Drag + Weight*sin()
= 10.9 lbf L T V D  W 

9. ENDURANCE CALCULATIONS
Fuel Max. RPM = 1 ounce per minute
Total Endurance Time min.
Warm-up, Take-off, & Climb min max. RPM
Landing & Descent min ~ half RPM
Cruise & Loiter min ~ 90% RPM
Minimum Fuel Required = 25.5 ounces/engine
Fuel Reserve & Inert Fuel = 2.5 ounces/engine
Total Fuel Requirement = 56 fluid ounces
= 2.92 lbs

10. ROADMAP TO PROPELLER SELECTION
Varied propeller diameter and pitch to match
engine  propeller  airframe
Matched manufacturer’s within RPM range
Matched thrust and velocity requirements from constraint analysis and mission requirements.

11. PROPELLER ANALYSIS Gold.m was used to produce all results
Key in Inputs
The desired blade diameter and pitch
Manufacturer specified RPM range (9000 to 9500 RPM)
Desired operating flight velocity (33.6 ft/s)
Re-iterate using Outputs
Horsepower and Thrust
Final desired Outputs
1.8 HP within RPM envelope  lbf of thrust

12. PROPELLER ANALYSIS

13. PROPELLER ANALYSIS
9400 RPM

14. PROPELLER ANALYSIS
ηp = 0.379

15. PROPELLER CHOICE Diameter: 17” Pitch: 5” Theoretical Chord: 0.765”
RPM: 9,400 rev/min
Power: 1.79 HP
Advance Ratio: rev-1
Power Coefficient:
Thrust Coefficient:
Efficiency: 37.9%

16. PROPELLER ANALYSIS

17. PROPELLER ANALYSIS

18. PROPELLER ANALYSIS

19. CONSTRAINT DIAGRAM single engine operation
Propeller Efficiency of 37.9% used  1.4 HP engine required
Engine meets requirements  Analyze twin engine performance

20. Twin Engine cruise performance
Both engines 8250 rev/min
Cruise velocity 60 ft/sec
Efficiency 64.1 %
Torque ft-lbs
Advance ratio 0.308

21. Twin Engine maximum performance
Both engines 9500 rev/min
Maximum velocity 70 ft/sec
Efficiency 64.6 %
Torque ft-lbs
Advance ratio 0.312

22. FOLLOW-UP ACTIONS
Study actual propeller geometry to improve accuracy of results
Contact engine and propeller manufacturers
Determine fuel feed system

23. QUESTIONS?

24. APPENDIX PROPELLER COMPARISON
Different propellers compared
End results checked with availability
17” x 6”
@ 8800 RPM
17.5” x 5”
@ 9000 RPM
17” x 5”
@ 9400 RPM
HP required
1.790 HP
1.745 HP
1.780 HP
Thrust Produced
lbf
lbf
lbf
Propeller Efficiency
37.74%
38.74%
37.93%