Propulsion QDR AAE 451 Fall 2006 Team 4 Tung Tran Mark Koch Matt Drodofsky Matt Lossmann Ravi Patel Ki-bom Kim Haris Md Ishak Andrew Martin
Overview Selection Process (propeller and motor) Geometric Propeller properties Motor Selection Power Supplies Cost Breakdown
Selection Process Run Main_System_Design.m @ 130ft/s to find propeller diameter Run gold.m for various P/D’s and maximize efficiency Using the equation J=V/(nD), the RPM’s of the motor can be found Blade pitch is calculated Cp is known and the power requirement can be calculated Find a motor that can satisfy the power requirement
Propeller Geometries Chose a P/D of 0.8. This is the highest value found in commercially built propellers This yields an advance ratio of 0.9
Propeller Geometries τ = .8 V = 130 ft/s J = .9 N = 173.33 rps Β = 57.85º Where: Tau = P/D R = propeller radius
Propeller Geometries From Raymer’s: Helical Tip speed for wooden prop not to exceed 850ft/s
Motor Selection We now know all the variables except Pin. Solving the equation above yields:
Motor Selection Rimfire 35-48-1000 outrunner brushless motor Continuous Amps – 50A Input Voltage – 11.1 – 14.8V Weight – 6 oz Kv – 1000 RPM/V Price - $69.99
Battery Selection Team Orion Avionics SLPB 1250mAh 7.4V 2S-1P 2 batteries 4 cell total 14.8 volt total Max discharge 72 amps 2500 mAh total Weight – 5.8 oz Price - $75.98 total
Speed Controller Castle Creations Phoenix-80 Brushless Motor Control 80A continuous power BEC of 3A Price - $135.99
Horsepower Calc
Max Flight Time
Cost Estimation Motor - $69.99 Speed Controller - $135.99 Batteries – $75.98 Propeller - $5 Total with Speed Controller – $286.96 Total without Speed Controller – $150.97
Questions?