Heavy Lift Cargo Plane

Group #1Matthew Chin, Aaron Dickerson

Brett J. Ulrich, Tzvee WoodAdvisor: Professor Siva Thangam

December 9th, 2004

Overview• SAE Aero Design Rules• Conceptual Design

– Design Matrix• Materials• Budget• Boom• Wing Selection

– Previous Designs– Features

• Landing Gear• FEM Analysis• EES Calculations• Tail Plane Calculations• Team Dynamics & Conclusion

Design Concepts &

Materials Selection

SAE Aero Design Rules

• For Regular Class:– Wing Span Limit – maximum width of 60 inches– Payload Bay Limit – 5” x 6” x 8”– Engine Requirements

single, unmodified O.S. 0.61FX with E-4010 Muffler

– Take off time limited to a max of 5 minutes– Maximum takeoff distance of 200 ft and landing

distance of 400 ft

• Aero East Competition– Date: April 8–10– Location: Orlando, Florida

Conceptual Design (recap)

• Reviewed past design entries• Considered:

– Flying wing– Monoplane– Bi-plane– Two sequential wings

• Design alternatives were evaluated for performance, feasibility, and cost.

Design Decision Matrix

Materials• Balsa wood

– Ease of use– Used in rib manufacture– Fuselage

• Plywood– Stronger than balsa wood– Used in construction for wing– Will reinforce dihedral design

• Carbon fiber– Composite material– Stronger and lighter than other metals– Reinforce wings with rods

• Aluminum– Engine bracket– Landing Gear

• Thermal Monocot– Reduce parasitic losses on wings

Projected Budget

Wing Selection &

Boom Design

• Selected for competition in:– 2000: Eppler 211– 2001: Eppler 423– 2002: OAF 102– 2003: Selig 1223

• Our selection:– Eppler 423– High coefficient of lift

Previous Wing Selection

Camber 0.0992 Trailing edge angle[deg] 7.5231

Thickness 0.1252 Leading edge radius 0.0265

Wing Features• Eppler 423 - a subsonic high lift airfoil

– Camber 0.0992– Trailing edge angle 7.523° From XFOIL

– Thickness 0.1252– Leading edge radius 0.0265 Based on unit Chord

• Dihedral– Angle of 3.5°– 2” at ends (http://www.colorado-research.com/~gourlay/dome/hiFreq/)

• Horner Plate– ½” larger than thickness in one direction– 10% increase to the area of rib (http://www.rcuniverse.com/forum/Tip_Plates/m_2282825/tm.htm)

Main Wing

• Previous structural weakness• Model currently too complex for COSMOS to

mesh

22.5 lb on lower surface

fixed face

Symmetric model for FEM analysis

Boom• Balsa sheets versus Carbon Fiber rods

Chose Balsa sheets from reasons stated above

Balsa Sheets Characteristic Carbon Fiber rodsCheap Cost ExpensiveFragile Strength Durable

Easy to modify shape

Construction Hard to modify

Light Weight Light

More resistant to torque

Moment comparison

Succeptible to torque

• Taper– More Aerodynamic– Less Mass– Sleek design

FEM Analysis

Landing Gear &

Engine Mount

Landing Gear

• Weakness in past years – strength is a priority• Tricycle design: focus on main rear wheels

– Aluminum 6061– Parabolic spring (actually elliptical in shape)

http://www.ticonsole.nl/parts/springs/what.htm

Engine Mounting• Aluminum 6061• Mount for engine, secures to front face of fuselage (backing

plate to be used with through bolts)

Engine/Muffler 23.6 oz

EES Takeoff Calculations• Method derived from fluid mechanics text and

Nicolai’s ‘white paper’• Calculates take-off distance by two methods

→ yielding similar results• Key Inputs

– Weight (max) = 45lb– Fuselage length = 15”– Fuselage width = 6.5”– Boom length = 34”– Wingspan = 60”– Wing AR = 3

• Key Outputs– Vtakeoff ≈ 39 mph

– Takeoff distance ≈ 60’

• Other Outputs (sample)– Thrust (@Vtakeoff) ≈ 45 lb

– Drag ≈ 5 lb– Various Reynolds numbers– Area projected

Tail Plane Calculations

Tail Plane Function

• Aircraft control• Stabilize aircraft pitch• Small tail plane results in instability• Extra large tail plane increases drag

Tail Plane Size• Offsets all moments generated in flight

– Lift/Drag forces on primary airfoil– Pitching moment of primary airfoil about its

aerodynamic center– Pitching moment of airflow around fuselage– Pitching moment of tailplane– Lift/Drag forces on tail plane

• Tail drag force and pitching moment are negligible

Tail Plane Size

• Moments all taken about center of gravity

ttnacfusacaacg lNMMCzNxM ,

• Analysis generalized

• Lift/Drag forces resolved to act normal/parallel to airplane reference line

M / qcSW = CM

• Moments all converted to “coefficient” form

ww

ww

iLiDC

iDiLN

sincos

sincos

Tail Plane Size

• Profili Software utilized for lift/drag/moment coefficients

Cl vs Angle of Attack

y = -1.170E-05x4 + 5.367E-05x3 - 1.289E-03x2 + 1.019E-01x + 1.082E+00

R2 = 9.999E-01

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

-10 -5 0 5 10 15 20

Angle of Attack

Cl

• Lift coefficient of primary airfoil (Eppler 423) determined as a function of attack angle

• CD = f(CL)

• CM = f(α) ≈ -0.2

Tail Plane Size

• Downwash from primary foil effects tailplane (NACA 0012)

• Lift coefficients determined with Profili

• Pitching moment of the fuselage depended upon:– Change in airfoil pitching

moment with respect to angle of attack

– Change in lift coefficient with respect to angle of attack

– Fuselage “fineness ratio”

Tail Plane Size

• Mathematical model for tail plane size entered into EES

• Final tail plane minimum planform area: 183.4 in2

• Rule of thumb: Tail area is 15-20% of wing area

• Wing is 1200 in2

The Wrap Up

Chosen Design

Various Unused Features

Final Design

Team Dynamics

• Learned how difficult team work can be• In fighting over who was in charge often

resulted in wasting of time• Personality conflicts occasionally made

working environment difficult• Ultimately produced quality work

Concluding Remarks• Selected foils:

– Main Wing: Eppler 423– Tail Wing: NACA 0012

• Preliminary calculations estimate a lifting capacity of 30 lbs

• Plane ready for construction• Expect minor refinements over the coming

weeks subject to completion of add’l FEA tests

Your Feedback is Appreciated

Group #1Matthew Chin, Aaron Dickerson

Brett J. Ulrich, Tzvee WoodAdvisor: Professor Siva Thangam