SAE Aero Design ® East 2005 University of Cincinnati AeroCats Team #039 SAE Aero Design ® East 2005 University of Cincinnati AeroCats Team #039 Design Team Todd BarhorstDavid ChalkSteven J. Coppess Matthew CrummeyMatthew GoettkeKevin Harsley John LouisJames MountAlex Sullivan John Vandenbemden

Outline Basic Configuration Aerodynamics Structural Design Weights & Balance Stability & Controls Propulsion Performance & Optimization Conclusion

Box Wing – Span limitation dictates two wings, for greater planform area – Winglets draw vortices away from the wingtips, improving wing efficiency – Minimizes induced drag – Provides optimal Oswald span efficiency factor Traditional Tail – Relatively lightweight – Easy to construct Basic Configuration Example values for gap/span ratio of 0.2

Aerodynamics: Design Refinement TORNADO code used to analyze aerodynamics – Based upon Vortex Lattice Theory Wing gap – Gap-to-span ratio set to 0.6 Due to practical limitations Forward stagger (15 in) – Fuselage accessibility – Minimal efficiency impact Tapered winglets – Decreased weight – Decreased side area Improved lateral stability – Negligible effect on performance Final wing efficiency: e = 2.2

Application – High Lift – Low Reynolds Number Re = 300,000 Modified Eppler E423 – Advantages Relatively small moment Ease of construction – Modifications De-cambered by 25% Improved drag polar, higher L/D 2D Analysis performed with XFOIL C l Max 1.8 CmCm Aerodynamics: Main Wing Airfoil

NACA 0014 − Relatively High C L – Allows for smaller elevator – Produces minimal C D throughout operating conditions Re = 300,000 2D XFoil Data Widest of Drag Buckets Viewed Aerodynamics: Horizontal & Vertical Tail Airfoil

Wind-tunnel airfoil testing – UC Instrumentation – Differential Pressure Sensor Aerodynamics: Wind Tunnel Testing (Main Airfoil) Test Conditions – Re: 200,000 – 400,000 – AOA: -4º – 17º Flight Telemetry Package – AOA Probe – Pitot-Static Probe – RPM Sensor – Temperature Sensor Experimental vs. Published Data - Tunnel Data Verified

Stall Aerodynamics: Lift vs. Alpha & Drag Buildup Total Drag 3D Wing Fuselage Horizontal Tail Vertical Tail Max L/D Max Climb Angle Lift Off Stall Total A/C Total A/C Trim 3D Wing Max L/D Max Climb Angle Lift Off Stall

Aerodynamics: Drag Polar & Lift-to-Drag Tot al A/ C Total A/C Trim 3D Wi ng Max Clim b Angl e Lift Off StallStall Total A/C Total A/C Trim 3D Wing Max L/D Max Climb Angle Lift Off Stall Total A/C Total A/C Trim 3D Wing Max L/D Max Climb Angle Lift Off Stall

Structural Design: Airfoil Construction Semi-monocoque construction method – Utilized for all airfoils (wings, winglets, and tails) Components: – Composite-reinforced spars Spar caps: Graphlite © carbon fiber rods – High strength-to-weight ratio – Main load-bearing members Fiberglass shear web – Balsa wood ribs Lightweight Secondary members – Front portion of D-spar Fiberglass skin – Monokote skin

Structural Design: Airfoil Construction Semi-monocoque construction method – Utilized for all airfoils (wings, winglets, and tails) Components: – Composite-reinforced spars Spar caps: Graphlite © carbon fiber rods – High strength-to-weight ratio – Main load-bearing members Fiberglass shear web – Balsa wood ribs Lightweight Secondary members – Front portion of D-spar Fiberglass skin – Monokote skin

Structural Design: Airfoil Construction Semi-monocoque construction method – Utilized for all airfoils (wings, winglets, and tails) Components: – Composite-reinforced spars Spar caps: Graphlite © carbon fiber rods – High strength-to-weight ratio – Main load-bearing members Fiberglass shear web – Balsa wood ribs Lightweight Secondary members – Front portion of D-spar Fiberglass skin – Monokote skin

Structural Design: Airfoil Construction Semi-monocoque construction method – Utilized for all airfoils (wings, winglets, and tails) Components: – Composite-reinforced spars Spar caps: Graphlite © carbon fiber rods – High strength-to-weight ratio – Main load-bearing members Fiberglass shear web – Balsa wood ribs Lightweight Secondary members – Front portion of D-spar Fiberglass skin – Monokote skin

Structural Design: Airfoil Construction Semi-monocoque construction method – Utilized for all airfoils (wings, winglets, and tails) Components: – Composite-reinforced spars Spar caps: Graphlite © carbon fiber rods – High strength-to-weight ratio – Main load-bearing members Fiberglass shear web – Balsa wood ribs Lightweight Secondary members – Front portion of D-spar Fiberglass skin – Monokote skin

Structural Design: Airfoil Construction Semi-monocoque construction method – Utilized for all airfoils (wings, winglets, and tails) Components: – Composite-reinforced spars Spar caps: Graphlite © carbon fiber rods – High strength-to-weight ratio – Main load-bearing members Fiberglass shear web – Balsa wood ribs Lightweight Secondary members – Front portion of D-spar Fiberglass skin – Monokote skin

Structural Design: Fuselage Semi-monocoque construction method Components – Bulkheads Carbon fiber High strength, lightweight Provides attach points – Skin Fiberglass Formed on full-scale foam model Lightweight – Stringers Graphlite © rods Embedded in skin

Structural Design: Fuselage Semi-monocoque construction method Components – Bulkheads Carbon fiber High strength, lightweight Provides attach points – Skin Fiberglass Formed on full-scale foam model Lightweight – Stringers Graphlite © rods Embedded in skin

Structural Design: Fuselage Semi-monocoque construction method Components – Bulkheads Carbon fiber High strength, lightweight Provides attach points – Skin Fiberglass Formed on full-scale foam model Lightweight – Stringers Graphlite © rods Embedded in skin

Structural Design: Fuselage Semi-monocoque construction method Components – Bulkheads Carbon fiber High strength, lightweight Provides attach points – Skin Fiberglass Formed on full-scale foam model Lightweight – Stringers Graphlite © rods Embedded in skin

Structural Design: Landing Gear Main gear struts – Laminar composite construction Stacked Graphlite © rods Wrapped with woven carbon fiber fabric – Analysis Stress & deflection calculations Experimental testing Other components – Spring steel front gear – Alumimum wheels

Main gear struts – Laminar composite construction Stacked Graphlite © rods Wrapped with woven carbon fiber fabric – Analysis Stress & deflection calculations Experimental testing Other components – Spring steel front gear – Alumimum wheels Structural Design: Landing Gear

Main gear struts – Laminar composite construction Stacked Graphlite © rods Wrapped with woven carbon fiber fabric – Analysis Stress & deflection calculations Experimental testing Other components – Spring steel front gear – Alumimum wheels

Weights & Balance CG Aerodynamic Center Neutral Point – 2.5 inches behind CG forward stability – Above fuselage pendulum effect Stability Verification – 2 flight tests – Pilot deemed all modes stable Neutral Point

Stability & Controls: Moment vs. Alpha C m as a function of AOA for three elevator deflections: 0º, and ± 5º C m as a function of AOA for three centers of gravity: nominal CG ± 1 inch

Propulsion: Torque & Power Curves Engine was specified: OS 0.61 FX engine, E-4010 muffler Static torque stand tests verified engine performance

Propulsion: Propeller Selection Static thrust tests were performed Propeller performance was quantified in terms of maximum thrust Previous UC performance aircraft used 14-inch propeller New design uses 14.5-inch propeller, with improved performance

Propulsion: Installed Power &Thrust Max power and thrust curves were determined via the propulsion model

Performance & Optimization: Trade Study Trade study determined viable wing chord length vs. total design weight Based upon 190 ft takeoff distance limit Minimum climb rate at takeoff  200 ft/min Used to determine final design: 1.5 ft chord, 32 lbf total design weight (22 lbf payload) 210 ft/min

Performance: Ground Roll & V-N Diagram

Conclusion Raising the bar – Box wing design Minimizes induced drag Optimal Oswald efficiency – Telemetry package Wind tunnel & flight testing Real time performance – Composite construction Advanced materials Great strength/weight

(group picture) Questions?

Stability & Controls: Lateral Motion Calculations (BACKUP) Sideslip Angle Roll Rate Yaw Rate Roll Angle Dutch Roll Spiral Mode Roll Mode

Performance: Payload Prediction Chart