1. DR2 Propulsion PDR I Preliminary Design Review September 28, 2000 Presented By: Mark Blanton Team DR2 Chris Curtis Loren Garrison Chris Peters Jeff Rodrian

2. DR2 Propulsion PDR I Procedure For Propeller, Gearbox, and Motor Selection –Historical Design – Tow Plane (Spring 98) Payload/Size Comparable –Inventory of Motors and Propellers Largest Motor – Astroflight25G Propellers of Different Size –Astroflight Specifications Motor Weight Power Output Propeller Size Recommendation –Motocalc Suggestion Gearbox Selection based on Motor Selection

3. DR2 Propulsion PDR I Electric Motor Selection –Selection based on tow plane characteristics and inventory Electric Motor Specs (www.astroflight.com) –ManufacturerAstroflight –MotorAstroflight 25G Horsepower0.6705 hp Motor Efficiency0.78 Motor Constant971 RPM/Volt Rated Voltage7.72 Volt Rated Cell Number10 – 16 cells

4. DR2 Propulsion PDR I Propeller Selection –Astroflight recommendation with the Astroflight 25G –Selection Master Airscrew Propeller Aerodynamic Properties –Diameter12 inches –Pitch Thickness 8 inches –Twist DistributionEven –ShapeUncambered

5. DR2 Propulsion PDR I Propeller Aerodynamics (results from gold.m) –Thrust Coefficient vs. Advance Ratio –Cp = 0.0244

6. DR2 Propulsion PDR I Propeller Aerodynamics (results from gold.m) –Thrust Coefficient vs. Advance Ratio –Ct = 0.0804

7. DR2 Propulsion PDR I Gearbox Selection –Astro 035-15 2.38:1 Gearbox Currently an assumption of the Gearbox attached to the Astroflight 25G Motocalc makes an initial assumption of this gearbox Speed Controller Selection –Astro 211 Motocalc makes an initial assumption of this speed controller Maximum Current 75 Amps Weight 0.89 oz

8. DR2 Propulsion PDR I Cell Selection –Sanyo 1700SCR Currently in inventory Capacity1.700 A – hr Weight1.89 oz. –Cell Number Recommended Number10 – 16 Selected Number14 Motocalc Predicted Endurance13 minutes –Takeoff to Land –90% throttle

9. DR2 Propulsion PDR I Mission Requirements –Sufficient Thrust Requirement Aircraft Thrust Requirement of 0.107 hp Propeller Thrust sufficient –Battery Endurance Time exceeds Mission Time