Wing Trade Study

Wing Process Flowchart

Test at CruiseConditions

Does design meetcruise requirements?

Test slow flightperformance

Test design withnew high lift

devices

Design a new plainflap

Design a newflapperon

Design a newFowler flap

Does the bestavailable option meet

requirements?

Can the overalldesign beimproved?

Yes

No

Create a newdesign

Begin Testing Process

No

No - Start Over

Yes

Complete Design Meetsrequirements

Yes

CFD (In)Validation

Cruise Wing Optimization

Cruise wing optimization Guidelines

• Maintain the same or lower drag

• Increase lift by 300 pounds

• Maintain the same or lower surface area, and maintain the same or lower wingspan

So, improve lift to drag ratio and wing loading of the baseline wing. Note, only considering cruise conditions at the moment.

Airfoil Selection

Two different airfoil shapes were investigated in xfoil in order to determine the effect of camber on L/D and maximum Cl.

Airfoil Selection

Curves made in x-foil. Both plots are of airfoil 1 with varying cambers at Re=6 million

Airfoil selection

Curves made in x-foil. Both plots are of airfoil 2 with varying cambers at Re=6 million

Optimized wing

Plain Flaps/Slats Study

Deep Chamber-High Lift-Low Speed-Thick Wing Section-Good For Transport, Freighters and Bomber Planes. 

                                                                           

Root: ARA-D 6%

Tip: N-14

AOA LIFT DRAG SHEAR Y SHEAR X

2 7880.44 524.86 2.23358 36.9293

3 7989.5 721.219 0.514376 29.2791

4 9079 250.788 2.74131 42.5362

AOA LIFT DRAG

2 7857.322 799.5637

3 7940.805 1138.369

4 9039.39 883.4961

Lift and Drag vs AOA

0

2000

4000

6000

8000

10000

2 2.5 3 3.5 4 4.5

AOA

Lif

t/D

tag

Lift

Drag

Airfoil:Root: ARA-D 6% Tip: N-14 Actual

Root: ARA-D 10%

Tip: N-14

Actual

AOA LIFT DRAG SHEAR Y SHEAR X

2 3924.37 305.341 0.675845 21.9988

3 4240.54 362.769 0.484363 17.5863

4 4685.58 156.189 2.20958 29.2097

AOA LIFT DRAG

2 3911.323 442.1135

3 4215.743 584.2046

4 4663.271 482.6581

Lift and Drag vs AOA

0

1000

2000

3000

4000

5000

2 2.5 3 3.5 4 4.5

AOA

Lif

t/D

rag

Lift

Drag

Airfoil:Root: ARA-D 10% T: N-14

Root: GOE 619AT18.5

Tip:S8035 for RC aerobatic 14% thick

AOA LIFT DRAG SHEAR Y SHEAR X

0 2814.83 329.742 -0.19212 12.4791

1 3321.04 362.867 -0.15592 10.1702

2 3777.61 150.541 0.600329 23.3197

3 3999.73 327.162 -0.02157 11.9194

4 4443.91 77.991 1.16475 24.4702

Lift and Drag vs AOA

0

1000

2000

3000

4000

5000

0 1 2 3 4 5

AOA

Lif

t/D

rag

Lift

Drag

Airfoil:Root: GOE 619 Tip: S8035 for RC aerobatic 14% thick

AOA LIFT DRAG

0 2814.83 329.742

1 3314.201 420.7719

2 3770.055 282.286

3 3977.126 536.0433

4 4427.644 387.7925

ACTUAL

Root: FX 66-182

Tip: FX 63-137 13.7%

ActualAOA LIFT DRAG SHEAR Y SHEAR X

0 2784.55 300.95 -0.12042 11.8663

1 3519.3 120.135 -0.15958 20.1406

2 4051.86 87.3311 0.547624 25.4323

3 4310.62 161.712 -0.00846 14.9382

4 4698.07 -29.0639 0.370025 23.3039

AOA LIFT DRAG

0 2784.55 300.95

1 3516.667 181.537

2 4046.344 228.6858

3 4296.249 387.0908

4 4688.653 298.7277

Lift and Drag vs AOA

-1000

0

1000

2000

3000

4000

5000

0 1 2 3 4 5

AOA

Lif

t/D

rag

Lift

Drag

Airfoil:Root: FX 66-182 Tip: FX 63-137 13.7%

Actual

AOA LIFT DRAG SHEAR Y SHEAR X

2 3127.13 312.689 -0.74498 30.7693

3 3441.45 81.1619 -0.24132 31.2829

4 3888.9 117.683 -0.06713 31.6899

AOA LIFT DRAG

2 3114.312 421.6338

3 3432.486 261.1622

4 3871.218 388.6723

Lift and Drag vs AOA

0

500

1000

1500

2000

2500

3000

3500

4000

4500

2 2.5 3 3.5 4 4.5

AOA

Lif

t/D

rag

Lift

Drag

Airfoil 2:Root: FX 66-182 Tip: FX 63-137 13.7%

Leading edge slats accelerate the air in the funnel shaped slot (venturi effect) and blow the fast air tangentially on the upper wing surface through the much smaller slot. This "pulls" the air around the leading edge, thus preventing the stall up to a much higher angle of attack and lift coefficient (approximately 30 degrees). It does this by picking up a lot of air from below, where the slot is large, the disadvantage of the leading edge slat is that the air accelerated in the slot requires energy which means higher drag. As the high lift is needed only when flying slowly (take-off, initial climb, and final approach and landing) the temptation for the designer is to use a retractable device which closes at higher speeds to reduce drag.

Changing from a plain airfoil to an airfoil with flaps we have created an increase of curvature of the airfoil which gives part of the extra lift, but we have also created a depression, a low pressure near the trailing edge, which sucks the air over the upper part of the airfoil and helps it to overcome the centrifugal forces present when the air flow has to come around the nose of the wing. It is like a pull acting from the trailing edge and pulling the air around the leading edge, thus preventing separation

Plain Flaps

Actual

FLAP ANGLE LIFT DRAG SHEAR Y SHEAR X

30 660.962 24.1119 0.047339 1.03629

35 663.971 41.4389 0.025018 1.03319

40 767.984 -12.5116 0.084433 1.51058

FLAP ANGLE LIFT DRAG

30 638.5976 172.178

35 637.6317 189.7378

40 751.1151 160.5679

Lift and Drag vs Flap Angle

-200

0

200

400

600

800

1000

30 32 34 36 38 40 42

Flap Angle

Lif

t/D

rag

Lift

Drag

Plain Flap at AOA of 13

And

Stats

Plain

Flaps

Modified Stat

Modified StatFLAP ANGLE LIFT DRAG SHEAR Y SHEAR X

30 591.342 -1.9466 0.143694 1.66964

35 599.448 1.05206 0.124249 1.19405

40 630.246 13.7779 0.129761 0.973575

Lift and Drag vs Flap Angle

-100

0

100

200

300

400

500

600

700

30 32 34 36 38 40 42

Flap Angle

Lift/

Drag

lift

Drag

Lift and Drag vs Flap Angle

0

100

200

300

400

500

600

30 32 34 36 38 40 42

Flap Angle

Flip/D

rag

Lift

Drag

FLAP ANGLE LIFT DRAG SHEAR Y SHEAR X

30 508.992 31.6069 0.115304 1.08775

35 488.247 31.2781 0.118123 1.25778

40 566.021 41.672 0.135978 1.05862

Fowler Flap Study

Fowler flap study

1 non-slotted fowler design

•Need track system

•Most increase in lift

2 slotted fowler flap designs

•Can use offset hinge

•Less increase in lift

Non-slotted fowler flap

• Provides the highest increase in surface area

• Requires largest movement of flap

Slotted fowler flap

• Doesn’t provide as much increase in wing area

• Doesn’t require as much movement

Non-slotted flap design

from “AERODYNAMIC CHARACTERISTICS OF A WING WITH FOWLER FLAPS INCLUDING FLAP LOADS, DOWNWASH, AND CALCULATED EFFECT ON TAKEOFF”, Platt, Robert C, Langley Research Center, 1936, document ID: 19930091607

Non-slotted flap design

• Optimum position of leading edge of flap is

X=c, Y=-.025c

• Optimum flap deflection angle is 40 degrees for Reynolds number of 300,000

Note: optimum position is generally true for most airfoil shapes, but optimum angle isn’t as general, as it also depends on the flap shape too.

Non-slotted flap design

30% of the chord at all stations104 inches long, which is 48% span of wing (including the portion inside fuselage)30 degrees deflection, hedging on safety against uncertainty in flow separationResults using sea level conditions at 60 knots:AOA 10, Cl = .55, produces 844.2 pounds of liftAOA 13, Cl = .52, produces 899.8 pounds of lift, has severe flow seraration

Slotted flap design guidelines• Optimum position of flap leading edge depends

primarily on the shape of the slot, and is best determined by experiment

• In general, moves inward when lip is increased but is generally about .01c forward of lip

• Usually a slot opening on the order of .01c or slightly more is best.

• Best Cl’s are achieved using flaps with a wing shape. Avoid flaps with blunt leading edge.

from “Theory of wing sections”, Ira H. Abbott and Albert E. von Doenhoff, p. 212-213. Dover Publications, NY, 1959.

Slotted flap design

Two different shapes of slots with different flap shapes. The one on the right has a small lip with max cl=2.57, the one on the left is a smooth slot with max cl=2.35.

Slotted flap design

On the left is a slot with a larger lip and with a maximum Cl=2.65. On the right is a plot of the effect slot entry radius has on maximum Cl.

from “Wind-tunnel investigation of an NACA 23012 airfoil with various arrangements of slotted flaps”, Wenzinger, Carl J; Harris , Thomas A, Langley Research Center, 1939, ID: 19930091739

Slotted flap design 1

30% of the chord at all stations104 inches long, which is 48% span of wing (including the portion inside fuselage)30 degrees deflectionResults using sea level conditions at 60 knots:AOA 10, Cl = .6, produces 840.5 pounds of liftAOA 13, Cl = .7, produces 980.5 pounds of lift

Slotted flap 1 with slot in flap

30% of the chord at all stations104 inches long, which is 48% span of wing (including the portion inside fuselage)30 degrees deflectionResults using sea level conditions at 60 knots:AOA 10, Cl = .6, produces 841.5 pounds of liftAOA 13, Cl = .8, produces 1125.4 pounds of lift

Slotted flap design 2

30% of the chord at all stations104 inches long, which is 48% span of wing (including the portion inside fuselage)30 degrees deflectionResults using sea level conditions at 60 knots:AOA 10, Cl = .63, produces 883 pounds of liftAOA 13, Cl = .75, produces 1050 pounds of lift

Slotted flap 2 with slot in flap

30% of the chord at all stations104 inches long, which is 48% span of wing (including the portion inside fuselage)30 degrees deflectionResults using sea level conditions at 60 knots:AOA 10, Cl = .65, produces 916 pounds of liftAOA 13, Cl = .654, produces 921 pounds of lift

Comparison

• Non-slotted flap was calculated to have the least lift.

• Slotted flap 1 produced more lift with a slot in the flap at AOA 13 than slotted flap 2.

• Slotted flap 2 produced more overall lift without a slot in the flap than slotted flap 1.

• Conclusion: Design 2 is better, but the slot on the flap isn’t optimized.

Flapperon Study

FLAPPERON DESIGN

DIMENSIONS OF FLAPPERON

COSTS / BENEFITS

• COSTS– Increased drag when compared to non-

deployed flapperons. Possibly caused by flow separation due to gap between wing and flapperon when deployed.

– Could be difficult to work mechanically with the pulley system in place now.

– Hard to control during landing due to adverse yaw effects.

• BENEFITS– Increase camber during landing. – Increase lift due to increased camber.

• Optimal position is with flapperons deployed 40°

Cargo Pod Design

Front Fairing (2)

Rear Fairing

Attachment Method Design

Attachment Brackets

Rough Solid Works Models

Front Attachment to Longerons

Plugs for Non-use

Rear Longeron Attachment

Example of floor with Longerons

Screw holes

• Screw Holes are 3/8 in. in diameter.

• Plug screw in to holes when Pod is not attached

Attachment from Belly to Pod

Piece from Pod to Belly

Belly/Pod attachment

• The Belly to Pod piece screws into front longeron attachment.

• Pod to belly piece is embedded into Fiberglass Pod.

• Belly/Pod pieces bolt together

Pod Size Goals

• Two golf bags with clubs

• Two pares of downhill skis

• Minimize drag

• Clear ground on fully loaded landing

• Clear ground on tail strike

• Easy to remove

12:40 AM

Solid works attached Pod model

12:40 AM

Clearance

12:40 AM

Solid Works model

12:40 AM

Pod Ground Clearance

12:40 AM

Pod wheel Clearance

12:40 AM

Golf Bag

Width 10 in

Height Bag 34 in

Height with clubs 50 in

Golf Bag Size

12:40 AM

Golf Bag Clearance

12:40 AM

SkisLength (cm) 173 180

Side cut tip(mm) 130 135

Waist (mm) 96 99

Tail (mm) 124 125

Weight (g for one ski) 1970 2210

http://www.salomonski.com/us/products/XW-Sandstorm-1-1-1-788918.html12:40 AM

Cody’s Stuff – Performance, weights, drag

Failure Modes and Effects Analysis

Enviromental Impact

Problem Probability Severity Mitigation

High Lift Device Flutter due to failure Low High Pull Parachute.

High Lift Device Flutter due to aerodynamics Medium High Test for natural frequencies. Avoid frequencies of prop and install dampening.

Cable/Mechanical Failure Low High Pull Parachute.

High Lift Device Extension/Retraction Failure Low Low Install mechanical indicator to inform pilot.

Spin Entry Medium Medium Install warning placards and mandate anti-spin pilot training.

High Lift Device Detachment Low High Design fasteners to release when a partial failure occurs. Pull Parachute.

Icing High Varies Incorporate existing deicing equipment into new design.

Collision Damage Medium Medium Reinforce leading edge. Pull Parachute.

Wing Detachment Low Very High Pull Parachute.

Internal Fuel Leak Low MediumInstall fluid detector and warning device. Instruct pilot to deactivate electronics and land immediately.

External Fuel Leak Low Low Instruct pilot to land immediately.

Lightning Strike Medium Medium Install dissipating mesh in the wing and high lift devices.

Heat Damage Medium Low List warnings in Pilot's Operating Handbook.

Problem Probability Severity Mitigation

Pod hits the ground Medium Low Fasteners designed to shear off and release pod.

Partial Attachment Failure Low High Remaining attach points designed to shear off.

Foreign Object Collision Medium Low Reinforce the nose of the pod.

Front End Overheating High Medium Attach a metal heat sheild to the nose.

High G Failure Medium High Designed to withstand a 4G manuever.

CG Out of Balance Due to Loading High High Warn the pilot in the Pilot's Operating Handbook and install placards.