Aerial Search and Supply ASn S AAE 490

Aerial Search and Supply (ASn. S) AAE 490 K Project Bill Fredericks Joel Gentz Phil Wagenbach Cynthia Fitzgerald Ben Jamison 1

Overview • Mission Concept • Requirements • Constraint Analysis • Parasitic Drag Estimation • Aspect Ratio • Sizing • Weight Estimation • Propulsion • Wing and Tail Geometries • Structural Design • Wing Spar Loading • Fuselage Tests • Hardware and Electronics • Fuselage Design • Wing Attachment Method • Basic Construction Method 2

Mission Concept • Take off from a small field • Autonomously search disaster area for victims with onboard autopilot/GPS using camera payload • Upon finding victim mark waypoint • Aircraft sprints back to field and lands • Camera payload is changed out for med kit and supplies to be dropped on victim • Aircraft takes off and sprints back to victim and drops payload • Returns and lands • Cost must be within the capability of city fire departments 3

Requirements • 5 lb Payload • Camera, Transmitter, and Batteries or • Water, Food, and Medical Kit • • 50 yard Unassisted Takeoff (Paved Surface) 90 mph Sprint Capability 25 mph Stall Speed 1 hour Endurance 4

Constraint Analysis Takeoff Sprint Landing Stall Speed 5

Parasitic Drag Estimation • Typical single engine GA airplane (From Raymer) • CDo =. 022 • CDwet =. 0055 • Only Skin Friction Drag (Re = 200, 000 Turbulent) • CDwet =. 003 CDo =. 0124 • Lower wetted / wing area ratio of our aircraft leads to less drag • CDo =. 0207 • Used CDo =. 024 in constraint analysis to be more conservative 6

Aspect Ratio Choice • CDo =. 03 • This is even more conservative than the constraint analysis to be sure we hit L/D of 10 • Oswald’s Factor =. 7 • Weight = 1 Settled on an Aspect Ration of 7 7

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Constrain Analysis Inputs • • • rho =. 002377 (slug/ft 3) CLmax = 1. 2 g = 32. 2 (ft/s 2) Takeoff and Landing Distance = 150 (ft) Braking Force Fraction =. 3 (lbf/lbf) Stall Speed = 25 (mph) Oswald’s Factor =. 7 AR = 7 Sprint Speed = 90 (mph) CDo =. 024 9

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Weight Estimation Assumptions • L/D = 10 • ELoiter = 1 (hr) • C =. 133 (1/hr) Loiter Takeoff Climb Landing WTakeoff = 21. 6 (lb) WPayload = 5. 0 (lb) WFuel = 1. 5 (lb) WEmpty = 15. 1 (lb) 11

Thrust Specific Fuel Consumption Assumptions • cbhp =. 6 lb. Fuel/(hp*hr) • Honda GX 35 @ 6000 RPM • ηprop = 60% • V = 50 mph TSFC Notes: • Typical GA . 25 • High-Bypass Jet . 4 • Low-Bypass Jet . 7 • Pure Jet . 8 Aircraft Design: A Conceptual Approach Daniel P. Raymer AIAA Education Series 12

Design Point • Wing Loading = 1. 91 lb/ft 2 (30. 56 oz/ft 2) • Wing Area = 11. 31 ft 2 • Thrust to Weight =. 28 • Thrust = 6. 05 lb • Speed = 90 mph • Power = 1. 45 hp 13

Propulsion • Modify small string trimmer engine • 1. 5 hp @ 6000 rpm Honda GX 35, mini 4 stroke engine • (http: //www. honda-engines. com/gx 35. htm) • Most efficient and light engine (5. 75 lbs before conversion) • Carr Precision, Oregon • $530 for a converted engine • (http: //www. carrprecision. com/) 14

Wing Sizing • Based on the wing loading calculated in constraint analysis (1. 91 lbs/ft^2) • Aspect ratio from ideal L/D vs. CL plot 15

Tail Sizing Our computed wing geometry: Area= 11. 31 ft 2 Chord length= 1. 27 ft Wing Span= 8. 89 ft Possible values (pulled from Raymer) for General Aviation single engine: Horizontal CHT: 0. 70 Vertical CVT: 0. 04 Equations: SVT= CVT*bw *Sw /LVT SHT = CHT*Cw *Sw /LHT Computed Tail Areas: SVT= (0. 04)*(8. 8 ft)*(11. 31 ft 2) / (3. 5 ft) = 1. 13746 ft 2 SHT =( 0. 70)*(1. 27 ft)*(11. 31 ft 2) / (3. 5 ft) = 2. 87274 ft 2 *Using 42 in. (3. 5 ft) for LVT and LHT 16

Airfoil Shape • Researched both Epler and NACA airfoils • Compared NACA 4412 and E-193…very similar • Planning on using NACA 4412 (common use, more data) 17

Airfoil Characteristics 18

Airfoil Characteristics 19

Wing Spar Loading Takeoff Weight 25 lbs G Loading 3 Safety Factor 2 Design Load 150 lbs Span 8. 88 ft Span Loading 16. 89 lbs/ft Root Shear 75 lbs Root Moment 168. 16 ft*lbs 20

Wing Spar Dimensions Cord 1. 27 ft % Thick. 12 Spar Depth 1. 7 in Wood Type Sitka Spruce Wing Depth. 1524 ft Wing Depth 1. 8288 in σx 5613 lbs/in 2 Spar cap. 5 in x. 8025 in • Balsa didn’t have the strength • Wing spar will be made of sitka spruce 21

Wing Shopping List • Ribs Need 41 • • • (8. 88’ / 3” = 35. 2 ribs) Plus one for the end Plus 2 for dihedral Plus 2 for extra root attachment 4 will be 1/8” plywood at root attachment • Should be extra cross section plywood • 13 1/8” x 2” x 48” • • Spar need 2 1” x ½” x 5’ (Spruce) Spar need 2 1” x ½” x 5’ (Balsa) Rear Spar 4 1/8” x 2” x 3’ Leading Edge Spar • 1/8” x 1/8” Use extra from rear spar • Leading edge wrap • Block for fuselage attachment • 1” x 2” x 12” 22

Fuselage Construction Test • Decided on just Balsa for simplicity and weight. • Considered two ideas • Stick frame ribs with skin stringers • Solid Ply ribs with stick stringers 23

Fuselage Construction Test • Stick frame cross sections with solid skin was far superior • Weight <. 2 lbs for 5”x 12” section • Held > 130 lbs. • Was stood on top of by team member and only crushed top surface 24

Fuselage Shopping List • Firewall – 6’’ x ¼’’ Ply (1) • Front Ribs – 6’’ x 6’’ 1/8’’ Ply (13) • Back Ribs – 6’’ x ¾’’ x 1/8’’ Balsa Sticks (14) • Skin Sides – 3’’ x 6’’ x 1/16’’ Balsa Sheet (Enough for two wide on four sides) • Skin Angles – 1’’ x 6’’ x 1/8’’ Balsa Sheet (Enough for 1’’ on each bottom corner for entire length) 25

Previous 490 Materials • Prof Sullivan said he could help us with nearly everything • List compiled so far: • • 6 Channel Radio transmitter/controller and receiver Servos (types: elbow vs cross etc) Servo arms Control Surface fixtures • In contact with Prof Andrisani: Cannot use the “loft” or the Lockers. Need to contact Madeline 26

Controls Update - Meet at ASL with Matt and Ben to take inventory - Will be using JR XP 6102 Controller/receiver combination (6 channel) - Matt still locating servo’s/control arms; plenty of elbows - Need to order - Servos, pivot arms, hinges - Pico Pilot/Micro Pilot – available to use AFTER successful flight without – can use to work basic understanding of software 27

Wing Attachment ideas • Bolt through top of fuselage, set wing over bolt, fix on top of wing • Canvas straps • Fuselage “hat” idea 28

Wing Attachment Diagram 29

Final Fuselage Design • The Fuselage will use a combination of both tested designs. • The fire wall will be 6”x 1/4” Birch Plywood • From the firewall to the T. E. of the wing will be 6”x 1/8” Birch Ply cross sections with 3”x 1/16” Balsa skin on the sides and 1”x 1/8” Balsa skin on the corners. 30

Fuselage • From the T. E of the wing to the tail will be 3/4”x 3/16” stick frame ribs with 3”x 1/16” Balsa skin on the sides and 1”x 1/8” Balsa skin on the corners, scaling down from a 6”x 6” cross section to 3”x 3” cross section at the tail. • The entire Fuselage will be flat on top for ease of connecting the Wing and the Tail sections. • Ribs will be placed every 3’’ throughout the Fuselage, except where the wing will connect to the body where there will be more. 31

Final Design • The Fuselage will be 64” long. • From the fire wall aft • With 24” of constant cross section from the fire wall aft. • All of the electronics (Micro pilot, receiver, battery and servos) will be located under the wing. • The fuel tank and throttle servo will be in front of the wing 32

Aerial Search n Supply (ASn. S) 33

Basic Fuselage Construction Steps • The first two steps in construction will be to mount the engine mount to the firewall and cut the appropriate cross sections around the fuel tank • Next, machine the plywood cross sections and make an adjustable jig for the stick frame cross sections • Lay all cross sections in a foam jig and glue bottom side, ensures the top will be flat and we will be able to see the taper before we glue 34

Basic Wing Construction Steps • • • Cut wing spars to proper dimensions Create template for ribs Machine ribs on computerized router Using foam jig assemble ribs and spars Build brackets for • Servos • Wing Bolts • Control Surface hinges • Cover front of wings with balsa skin 35

Questions? 36