1. Propulsion PDR #1 AAE451 – Team 3 October 7, 2003
Brian Chesko
Brian Hronchek
Ted Light
Doug Mousseau
Brent Robbins
Emil Tchilian

2. Method for Propulsion Selection
Use constraint diagram and engine database to pick engine
With given engine, find RPM range
Use gold.m in a loop to make plots
Pick pitch and diameter from gold.m results
Select available prop

3. Constraint Diagram

4. Engine Database

5. Ref. www.towerhobbies.com
Engine Comparison
O.S. Max 1.40 RX-FI
$ w/o muffler
3.5 BHP
1,800-10,000 RPM
1.78 lbs
O.S. Max 1.60 FX
$ w/muffler
3.7 BHP
1,800-10,000 RPM
2.04 lbs
Ref.

6. Ref. www.towerhobbies.com
O/S Max 1.60 FX
Chosen for cheaper price and increased power with very small weight penalty
gold.m run at ~65% throttle (7,000 RPM)
Data sheet gives ~.44 gallons or ~2.6 lbs of fuel for a 30 minute flight
Ref.

7. HP vs J at 7000 RPM Note: Diameter and Pitch vary Required Horsepower
J (1/rev)

8. Efficiency vs J at RPM of 7000
Note: Diameter and Pitch vary hp
J (1/rev)

9. Cp vs J at Pitch of 9 inches
Note: Diameter and RPM vary CP
J (1/rev)

10. Ct vs J at Pitch of 9 inches
Note: Diameter and RPM vary CT
J (1/rev)

11. Efficiency vs J at Pitch of 9 inches
Note: Diameter and RPM vary hp
J (1/rev)

12. Chosen Propeller Based on carpet plots from gold.m: RPM used = 7000
Pitch is ~9 inches
Diameter is 20 inches
Efficiency ~0.48
Ct~ 0.057
Cp~0.029

13. Chosen Propeller Based on gold.m: Tip speed check:
Thrust = 14lbs (per gold.m)
Tip speed check:
Tip Speed =
Tip Speed = 610 ft/sec

14. Closest Available Propeller
Zinger 20x8 Wood Pusher Propeller
20 inches in diameter with 8 inch pitch
Closest to 20x9 available
$25.99 from Tower Hobbies
Ref.

15. Summary of Results O.S. Max 1.60 FX engine chosen:
3.7 bhp
Uses ~2.6lbs of fuel for 30 minute flight
Zinger 20x8 Wood Pusher Propeller:
20 inches in diameter with 8 inch pitch
Efficiency ~0.48 at 7,000 RPM

16. Questions?

17. Ref. http://www.allstar.fiu.edu/aero/BA-Background.htm
Reasonability Check
Bootstrap approach taken by Dr. Lowry
parametric performance method
Ref.