DR2 Propulsion PDR I Preliminary Design Review II October 17, 2000 Presented By: Mark Blanton Team DR2 Chris Curtis Loren Garrison Chris Peters Jeff Rodrian

DR2 Propulsion PDR I Propulsion PDR II Presentation Content –Aircraft Parameters –Propeller Selection –Motor/Gearbox Selection –Speed Controller Selection –Motor Power Source –Motor/Component Price List

DR2 Propulsion PDR I Aircraft Characteristics –Values Required for Motocalc aircraft evaluation –Aerodynamics & Weight Wing Span92.52 inches Wing Area square inches Empty Weight98.52 ounces Flight Speeds Takeoff Speed23 ft/s Cruise Speed25ft/s

DR2 Propulsion PDR I Propeller Selection –Propeller clearance of the fuselage Propeller Minimum Diameter is 14 inches, hence propeller diameter –Gold.m Analysis vs. Motocalc Analysis Gold.m input includes the flight speed, and motor parameters Gold.m output includes propeller thrust and propeller power based on input Motorcalc input includes aircraft parameters, propeller size, motor, gearbox size, speed controller, and power source Endurance time can be evaluated from Motocalc as well as verification of the power used by the motor and propeller

DR2 Propulsion PDR I Propeller Selection –Propeller Pitch Selection Master Airscrew Propellers in Inventory Propeller Pitches available 6, 8, and 10 inch from Tower Hobbies –Propeller Flight Requirements Thrust and Endurance Time –Maximum Thrust Required at Takeoff lb –Thrust Required during Cruise0.7624lb –Required Cruise Endurance 17 ft/s00:12:00minutes

DR2 Propulsion PDR I Propeller Selection –Propeller Pitch Evaluation Pitch = 6 inch –Maximum Thrust at takeoff2.4889pounds –Underpowered for takeoff conditions Pitch = 8 inch –Maximum Thrust at takeoff3.2618pounds –Thrust during Cruise1.7937pounds –Endurance 17 ft/s00:14:57 –Thrust requirement and time requirement met

DR2 Propulsion PDR I Propeller Selection –Propeller Pitch Evaluation Pitch = 10 inch –Maximum Thrust at takeoff4.0128pounds –Thrust during Cruise1.545pounds –Endurance 25 ft/s00:17:44 –Thrust requirement and time requirement met Propeller Selected –Propeller Size of 14 x 10 inch selected because of the thrust advantage and higher endurance time

DR2 Propulsion PDR I Propeller Thrust Conditions During Takeoff –Takeoff Conditions Flight Speed23 ft/s RPM of Propeller5831 RPM Max. Thrust Required2.7607pounds Thrust Coefficient Integrated Thrust Value pounds –Takeoff Conditions exceeded Thrust available is 145% greater than maximum required thrust for liftoff Throttle Setting 100%

DR2 Propulsion PDR I Propeller Thrust Conditions During Cruise –Cruise Conditions Flight Speed25 ft/s RPM of Propeller3899 RPM Thrust Required0.7624pounds Thrust Coefficient Integrated Thrust Value pounds –Cruise Conditions exceeded Thrust available is 200% of minimum required thrust for cruise Throttle Setting 65%

DR2 Propulsion PDR I Takeoff C T Plot on the Left T = pounds Cruise C T Plot on the Right T = pounds

DR2 Propulsion PDR I Propeller Power Conditions during Takeoff –Takeoff Conditions Flight Speed23ft/s RPM of Propeller5831 RPM Motor Power Available hp Power Coefficient Propeller Power Required hp –Takeoff Conditions Exceeded Excess Power Total is 171% of Propeller Required Power Throttle Setting at 100%

DR2 Propulsion PDR I Propeller Power Conditions during Cruise –Takeoff Conditions Flight Speed25 ft/s RPM of Propeller3899RPM Motor Power Available hp Power Coefficient Propeller Power Required hp –Takeoff Conditions Exceeded Excess Power is 571% of Propeller Required Power Higher Efficiency at lower RPM Throttle Setting 65%

DR2 Propulsion PDR I Takeoff C P Plot on the Left P = hp Cruise C P Plot on the Right P = hp

DR2 Propulsion PDR I Propeller/Motor Gearbox Selection –Based on Engine SelectionAstro25G –Standard GearboxAstro Gearbox Characteristics –Gear Ratio 2.38:1 –Manufacturer attaches the gearbox –Weight incorporated with the motor weight

DR2 Propulsion PDR I Motor Selection –Selection based on current inventory, historical data point, and Motocalc electric motor evaluations –Comparison Drawn between Astro25G, 40G, and 60G Gear Ratio fixed at 2.38:1 Motocalc Filter set at 30 Amps – To be sure that the amperage is not too high –Verifies the combination of all components –Astro 40G Didn’t meet filter restrictions, passed endurance time with 00:13:23 at 25 ft/s –Astro 60G Passed endurance time with 00:13:28 at 25 ft/s –Astro 25G Passed endurance time with 00:17:44 at 25 ft/s

DR2 Propulsion PDR I Motor Characteristics –ManufacturerAstroflight –MotorAstroflight 25G Horsepower hp Weight12.5ounces Motor Efficiency0.78 Motor Constant971 RPM/Volt Rated Cell Number10 – 16 cells Aircraft Speed Controller –Astro 204D Characteristics Resistance0.005Ohm Maximum Current50Amps Weight1.1ounces

DR2 Propulsion PDR I Aircraft Power Source –Sanyo 1700SCR Number of Cells14 Capacity1.700 A–hr Weight1.89 ounces each –Endurance Requirement Required Endurance Time12 minutes Throttle Setting75% Estimated Endurance 100% Charge17 minutes 44 seconds Estimated Endurance 70% Charge12 minutes 24 seconds

DR2 Propulsion PDR I Motor Component Price List –Tower Hobbies Price List(Magazine and Online) –Tower Hobbies –Astroflight 25G$ (In Inventory) –Master AirScrew 14x10 inch propeller$ 5.29 –Astro :1 Gearbox$ 0 (attached to motor) –Astro 204D Speed Controller$ (In Inventory) In Inventory –Sanyo 1700SCR$ 69.86(14 count) –Total Cost $ (If batteries not available)

DR2 Propulsion PDR I Questions?