1 Design Group 2 Kat Donovan - Team Leader Andrew DeBerry Mike Kinder John Mack Jeff Newcamp Andrew Prisbell Nick Schumacher Conceptual Design for AME 441 Spring 2004

2 Group 2 – Ducted Design

3 Overview  Aircraft Configuration & Design Drivers  Comparison Aircraft  CAD Models  Spreadsheet Decisions ♣Airfoil Choice ♣Engine Selection ♣Weight & Drag Estimates ♣Static Stability  Conclusions & Lessons Learned  Design & Build Schedule

4 Aircraft Configuration (Requirements)  Powered by electric motor  Carry specified payload  Take-off in < 300 feet on grass  Planform area between 400 in 2 & 800 in 2  Radio control system with up to 7 channels Design Drivers  Maximize the climb rate  Maximize the level flight speed

5 Comparison Aircraft * Information from † Information from ‡ Information from Design and Construction of a Remote Piloted Flying Wing, May 2, 1994

6 CAD Models Electronics BoxBattery Pack (x2)Circuit Card ServoGPS ReceiverModem

7 CAD Models - Dimensions

8  NACA 6412 ♣Low Reynolds Number airfoil ♣t/c ratio large enough to house internal electronics Airfoil Choice

9 Sample Lift Estimation

10 Engine Selection: Astro Cobalt 15 Model No.p/n 615G Name05 Geared Gear Ratio2.38 to 1 Armature Winding7 turns Armature Resistance0.069 ohms Magnet TypeSm Cobalt BearingsBall Bearings Motor Speed1488 rpm/volt Geared Motor Speed652 rpm/volt Motor Torque/amp0.91 in-oz /amp Geared Torque2.17 in-oz /amp Voltage Range8 to 12 volts No Load Currrent2 amps Maximum Continuous Current25 amps Maximum Continuous Power400 watts Gear Motor Length3.3 inches Motor Diameter1.3 inches Motor Shaft Diameter5/32 inch Prop Shaft Diameter1/4 inch Gear Motor Weight9 oz Data from  Electric, brushless motor  Runs off 16-cell rechargeable battery pack

11 Power Estimate

12 Thrust Estimates

13 Thrust, Drag, Estimates

14 Weight & Drag Estimates Structure3.84 Landing Gear0.6 Engine (Cobalt 15)0.56 Propeller0.06 Servo (x4)0.32 Receiver & Battery0.25 GPS & Transmitter0.5 Electronics Box1.5 Speed Controller0.08 Main Battery0.65 Total:8.36 Aircraft Weights (lbs)

15 Static Stability Fuselage Length L (f)2 Wing Center of Lift L_ctr (x/L) m.a.c. (ft)

16 Conclusions & Lessons Learned  Flying wing to maximize rate of climb and level cruise speed  Ducted fan to increase propeller efficiency  Winglets to reduce drag  Tricycle landing wheels to prevent damage during landing  At least 24” separation of modem and GPS to limit interference

17 Design & Build Schedule 26 February: Present Detailed Design 4 March: Complete Parts List 16 March: Fabrication 6-9 April: Ground Tests April: Flight Tests

18 Group 2: Nick Schumacher Andrew DeBerry Andrew Prisbell Jeff Newcamp Kat Donovan Mike Kinder John Mack Questions?