Propulsion PDR I DR 2 Preliminary Design Review
- Slides: 9
Propulsion PDR I DR 2 Preliminary Design Review September 28, 2000 Presented By: Mark Blanton Team DR 2 Chris Curtis Loren Garrison Chris Peters Jeff Rodrian
Propulsion PDR I DR 2 • Procedure For Propeller, Gearbox, and Motor Selection – Historical Design – Tow Plane (Spring 98) • Payload/Size Comparable – Inventory of Motors and Propellers • Largest Motor – Astroflight 25 G • Propellers of Different Size – Astroflight Specifications • Motor Weight • Power Output • Propeller Size Recommendation – Motocalc Suggestion • Gearbox Selection based on Motor Selection
Propulsion PDR I • DR 2 Electric Motor Selection – • Selection based on tow plane characteristics and inventory Electric Motor Specs (www. astroflight. com) – – Manufacturer Motor • • • Horsepower Motor Efficiency Motor Constant Rated Voltage Rated Cell Number Astroflight 25 G 0. 6705 hp 0. 78 971 RPM/Volt 7. 72 Volt 10 – 16 cells
Propulsion PDR I DR 2 • Propeller Selection – Astroflight recommendation with the Astroflight 25 G – Selection Master Airscrew • Propeller Aerodynamic Properties – – Diameter Pitch Thickness Twist Distribution Shape 12 inches 8 inches Even Uncambered
Propulsion PDR I DR 2 • Propeller Aerodynamics (results from gold. m) – Thrust Coefficient vs. Advance Ratio – Cp = 0. 0244
Propulsion PDR I DR 2 • Propeller Aerodynamics (results from gold. m) – Thrust Coefficient vs. Advance Ratio – Ct = 0. 0804
Propulsion PDR I DR 2 • Gearbox Selection – Astro 035 -15 2. 38: 1 Gearbox • Currently an assumption of the Gearbox attached to the Astroflight 25 G • 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
DR 2 Propulsion PDR I • Cell Selection – Sanyo 1700 SCR • Currently in inventory • Capacity • Weight 1. 700 A – hr 1. 89 oz. – Cell Number • Recommended Number • Selected Number • Motocalc Predicted Endurance – Takeoff to Land – 90% throttle 10 – 16 14 13 minutes
Propulsion PDR I • Mission Requirements – Sufficient Thrust Requirement • Aircraft Thrust Requirement of 0. 107 hp • Propeller Thrust sufficient – Battery Endurance Time exceeds Mission Time DR 2
