1. Ashley Brawner Neelam Datta Xing Huang Jesse Jones
Aerodynamics PDR 2
Team 2: Balsa to the Wall
Ashley Brawner
Neelam Datta
Xing Huang
Jesse Jones
Matt Negilski
Mike Palumbo
Chris Selby
Tara Trafton

2. Overview Design Point Airfoil Selection Component Drag Buildup
Drag Polar
AR trade study
(CL)max Approximation
(Cl)max method
(CL)max Raymer method
Flap analysis

3. The Design Point 5.5 [lbs] Weight 0° Dihedral Angle 110 [ft/sec] Speed
Planform area based on approximated (CL)max and weight estimate
Dihedral angle of 0° taken from Roskam
Design speed decreased from 150 ft/sec
Designed to high speed mission
Weight
5.5 [lbs]
Dihedral Angle 0°
Speed
110 [ft/sec]
Horizontal Tail Span
1.5 [ft]

4. Airfoil Selection: Main Wing
Wing Section
NACA 1408
Gives approximate 2D Cl needed for dash
Relatively thin for minimizing drag
Thick enough for structural strength

6. Airfoil Selection: Tail
Tail Sections
Horizontal Stabilizer
Symmetric with low Cd over a wider range of a.o.a. compared to other similar airfoils
Symmetric Jones airfoil (≈8% t/c)
Vertical Stabilizer
NACA 0006

8. Drag Build-up Method (Raymer)
Cfc = Component skin friction coefficient
FFc = Component form factor
Qc = Component interference effects
Swet,c = Component wetted area
Sref = Wing planform

9. Component Coefficient of friction

10. Drag Build-up Method results
Inputs:

11. Drag Polar

12. AR Trade study

13. AR Trade study

14. (Cl)max Approximation
Compare XFOIL with Abbott & Doenhoff wind tunnel data
Conclusion
αClmax ≈ 0.8αClmax(XFOIL)

19. Flap analysis Ads Use (CL)max approximation from Raymer
Use XFOIL to find (Cl)max with flaps
Observation -
Flapped (Cl)max follows linear trend
Determine maximum achievable (CL)max
Find flap configuration that acheives optimal (CL)max

22. Flap analysis: (continued)
Use linear fit lines to find a Δ(Cl)max and then find Δ(CL)max with the following equation from Raymer:
ads
The ratio blank is based on the intial sizing of the wing area and tail span and is assumed to remain constant

23. Flap Geometry: flap hinge location (x/c) = 0.8
maximum flap deflection = 35°
constant (cf/c) flap
(CL)max (w/ flaps) = 1.06
(Cl)max (w/o flaps) = 0.85

24. Summary Table (CL)max (w/ flaps) 1.06 (CL)max (w/o flaps) 0.84 CD0
0.0253 AR 6 b
5 [ft]
croot
16.24 [in]
ctip
7.35 [in]
troot
1.3 [in]
ttip
0.6 [in]
Flap location (x/c)
0.8
Maximum flap deflection
35°

25. Questions?