Agent Blue Presentation (1 of 2)

University of Florida Wing Configuration Senior Design - Fall 2010

Airborne Research Engineering Systems

Presented by: Jason Cantrell, James Lasater, Kevin Rausch, Jason Rue 1

Previous Contracts

2

Contract Requirements • • • • • •

Commercially available propulsion system Propeller driven Electric powered, 20 A limit Batteries: 0.75 lbs, NiCad or NiMH Hand launched Box size 20’’ x 15’’ x 10’’

3

Missions Mission 1: Dash to Critical Target •4 minute flight with no payload •Completed ½ mile laps normalized to best overall Mission 2: Ammo Resupply •1.5 mile flight •Team determine payload size •Ammunition weight normalized to plane weight Mission 3: Medical Supply •1.5 mile flight •Team determines payload quantity •Medical supply quantity normalized by highest overall

4

General Aircraft Configuration •Conventional Body •Tapered Wings •V-Tail •Single Tractor Motor •Tail Dragger Landing Gear

5

Score Parameter Estimates Top Competition Estimates Parameter Aircraft Weight Mission 1: Completed Laps

Estimate 2 lb 5

Mission 2: Ammunition Weight

2 lb

Mission 3: Number of Medical Packets

18

6

Aircraft Design Aerodynamics

7

Initial Size Estimates

Initial Sizing Parameters Initial Size and Weight Wingspan

35 – 55 in

Aircraft Length

36 – 42 in

Tail Span

6 – 12 in

Empty Weight

2 – 4 lb

8

Airfoil Selection Parameter Cmo, plane

Requirement ~ -0.05

Rationale Reduce control surface workload for longitudinal trim Minimize trim drag -0.006 to -0.009 Decrease control force requirements Cmα, plane* Increase control surface effectiveness > 1.2 Takeoff attainable without high lift devices CL, max Minimize thrust required for takeoff ≤12% The plane is kept small, so a thin airfoil is Thickness Airfoil Selection Requirements warranted > 5° High stall so that maneuvers will not result Stall in stalling *Note: This Cmα value comes from prior contract experience, looking at top ranking teams

9

Airfoil Optimization • Airfoil optimization was conducted using XFLR5.

Lift, and Drag Polars for Various Airfoils

S2091-101-83 met provided criterion best

10

Airfoil Batch Analysis

11

Tail Configuration Optimization

• • • •

44 Combinations Lift, Drag and Moment Data Compiled Sort by Cmα V-Tail with 8”x7.5” sections and tail setback of 25.1”.

12

Tail Configuration Optimization

13

Aircraft Design Stability and Controls

14

Initial Configuration Optimization • Aircraft Tail Span Kept Constant While Changing Chord • Aircraft Tail Chord Kept Constant While Moving Span

Dutch Roll (Orange) and Short Period (Blue) with Constant Chord

Dutch Roll (Orange) and Short Period (Blue) with Constant Span 15

Configuration Optimization • Aircraft Tail Volume Kept Constant While Changing Distance From Wing • Final Optimization Varied Both Tail Length and Volume • Tested Parameters of 42 Different Configurations

Dutch Roll (Blue) and Short Period (Orange) with Changing Tail Length

Tail Volume (in2) 52 54 54 56

Chord (in) 5.778 6 5.4 5.6

Span (in) 9 9 10 10

Total Plane Length (in) 40.91 40.02 39.57 38.73

16

Static Stability of Recommended Aircraft • Static margin of 18.2% and Neutral Point is at 0.446 of chord.

17

Dynamic Stability Stability

Mode

ωn

η

ωd

ζ

t(1/2)

Short P

-9.92 13.12 8.59 0.76

Phugoid

-0.05

Roll Dutch Roll

-24.86

Spiral

0.05

-1.02

0.07

0.61 0.61 0.07 15.18 -

-

-

5.64 5.54 0.18 -

-

-

0.03 0.68 13.45

18

Aircraft Design Propulsion

19

Motor Configuration

Motor Configuration

0.30

Single Tractor 1

Double Tractor 0

Single Pusher 1

Double Pusher -1

0.10

1

0

1

0

0.10

1

1

-1

0

0.20

0

-1

0

1

0.20

0

1

0

1

1.00

0.50

0.10

0.30

0.10

FOM

WF

Weight Storage Options Ground Clearance Aero Efficiency Payload Feasibility Total

20

Static Thrust Vs. Max Speed

21

Mission Breakdown

Wing Span Weight Prop

Mission 1

Mission 2

Mission 3

50

50

50

43.07

61.9

61.9

13"x8.5"

14"x7.5"

14"x7.5"

Motor

Neu 1105/3.5Y-3000

Battery

9x Sanyo HR-4/5AUP

Static Thrust

35.1

38

38

Cruise

35

35

35

Max Speed

42

35

35

Score

0.3

0.33

0.42 22

Battery Selection

MotoCalc optimization results: •Type: NiMH •Density: 2000 mAh •Quantity: 9 cells •Weight: 0.72 lbs

23

Propeller and Motor Selection MotoCalc Propeller Optimization •Diameter: 14 in.

•Pitch: 7.5 in./rev •Material: Wood •Weight: 0.12 lbs

Motor Optimization •Castle Creations 1105/6D •4.4:1 Gear Ratio •200 Watts

24

Aircraft Design Structures

25

Critical Materials Wing Load Selection Analysis

Three-point bending analysis •Simulates highest acceleration •Required design point

Preliminary FEM Analysis •Critical loading occurs at midspan •Large stresses on stringers

26

Wing Materials Component Selection Models

27

WingMaterials Configuration Selection Weight 0.2

Mass

0.15

0.1

0.05

0 1 0.5 0 OD

10

5

15

0 Nstr

Weight as function of spar diameter and stringer

28

Wing Materials Design Selection Space 0.18

0.2

0.16

0.18

0.14

0.16

0.12

0.14 0.12 M ass

M ass

0.1 0.08

0.1 0.08

0.06

0.06 0.04

0.04 0.02

0.02 0

0

2

4

6

8

10

12

14

Nstr

0

0

2

4

6

8

10

12

14

Nstr

Low Density Stringers

High Density

29

Wing Materials Design Selection Space 0.2 0.18 0.16 0.14

Mass

0.12 0.1 0.08 0.06 0.04 0.02 0 0

2

4

6

8

10

12

14

Nstr

Average Density Stringers

30

Wing Materials Optimization Selection

Optimized Wing Configuration with Safety Factors •Ten 1/8” stringers distributed linearly •1/32” sheet across half chord on upper surface •0.5” spar at midspan, 0.312” or smaller at joint

Post-Prototype Optimization •Rib quantity and spacing •Fuselage attachment points 31