Critical Design Review AAE 451 Team 3 Project

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Critical Design Review AAE 451 – Team 3 Project Avatar December 9, 2003 Brian

Critical Design Review AAE 451 – Team 3 Project Avatar December 9, 2003 Brian Chesko Brian Hronchek Ted Light Doug Mousseau Brent Robbins Emil Tchilian

AAE 451 Team 3 Project Avatar Aircraft Name Avatar av·a·tar - n. - 1.

AAE 451 Team 3 Project Avatar Aircraft Name Avatar av·a·tar - n. - 1. <chat, virtual reality> An image representing a user in a multi-user virtual reality. Source: The Free On-line Dictionary of Computing http: //wombat. doc. ic. ac. uk/foldoc/ 2

AAE 451 Team 3 Project Avatar • • • Introduction Walk Around Design Requirements

AAE 451 Team 3 Project Avatar • • • Introduction Walk Around Design Requirements and Objectives Sizing Propulsion Aerodynamics Dynamics and Controls Structures Performance Cost Summary Questions 3

AAE 451 Team 3 Project Avatar Aircraft Walk Around • Wing Span = 14.

AAE 451 Team 3 Project Avatar Aircraft Walk Around • Wing Span = 14. 4 ft • Wing Chord = 2. 9 ft • T-Tail – NACA 0012 • A/C Length = 10 ft • Pusher • Internal Pod • Tricycle Gear • Low wing – Clark Y 4

AAE 451 Team 3 Project Avatar Design Requirements & Objectives • Maximum weight <

AAE 451 Team 3 Project Avatar Design Requirements & Objectives • Maximum weight < 55 lbs • Cruise speed > 50 ft/sec • Stall speed < 30 ft/sec • Climb angle > 5. 5° • Operating ceiling > 1000 ft • Flight time > 30 minutes • Payload of 20 lbs in 14”x 6”x 20” pod • Carry pitot-static boom • Spending limit < $300 • T. O. distance < 106 ft (~60% of Mc. Allister Park runway length) • Rough field capabilities • Detachable wing • Easy construction 5

AAE 451 Team 3 Project Avatar Constraint Diagram 6

AAE 451 Team 3 Project Avatar Constraint Diagram 6

AAE 451 Team 3 Project Avatar Propulsion 7

AAE 451 Team 3 Project Avatar Propulsion 7

AAE 451 Team 3 Project Avatar Chosen Engine • O. S. Max 1. 60

AAE 451 Team 3 Project Avatar Chosen Engine • O. S. Max 1. 60 FX-FI – – 3. 7 BHP @ 8500 RPM 1, 800 -9, 000 RPM 2. 08 lbs Fuel Injected Ref. www. towerhobbies. com 8

AAE 451 Team 3 Project Avatar Chosen Propeller 4 -blades • Zinger 16 X

AAE 451 Team 3 Project Avatar Chosen Propeller 4 -blades • Zinger 16 X 7 Wood Pusher Propeller – 16 inches in diameter with 7 inch pitch – 4 blades Ref. www. zingerpropeller. com 9

AAE 451 Team 3 Project Avatar Chosen Fuel Tank • Fuel tank chosen is:

AAE 451 Team 3 Project Avatar Chosen Fuel Tank • Fuel tank chosen is: – Du-Bro 50 oz. fuel tank – Available from Tower Hobbies – Located at the C. G. of aircraft – Good for up to 32 min. of flight time (when completely full). Ref. www. towerhobbies. com 10

AAE 451 Team 3 Project Avatar Takeoff EOM Integration Drag + Rolling Friction Thrust

AAE 451 Team 3 Project Avatar Takeoff EOM Integration Drag + Rolling Friction Thrust Velocity [ft/s] Velocity vs. Position at Takeoff Distance Within Constraint Position [ft] 11

AAE 451 Team 3 Project Avatar Max Velocity Maximum Velocity Thrust/Drag [lbf] Thrust Drag

AAE 451 Team 3 Project Avatar Max Velocity Maximum Velocity Thrust/Drag [lbf] Thrust Drag Flying Velocity [ft/s] 12

AAE 451 Team 3 Project Avatar Aerodynamics 13

AAE 451 Team 3 Project Avatar Aerodynamics 13

AAE 451 Team 3 Project Avatar Wing Dimensions • Prandtl’s Lifting line theory used

AAE 451 Team 3 Project Avatar Wing Dimensions • Prandtl’s Lifting line theory used for aerodynamic modeling of the lifting components • Input parameters: AR, a 0, a. L=0, a. • Lifting Line Model Gives CL, CDi at prescribed a • CDvisc found using Xfoil which was used to obtain CD = CDi+CDvisc 5° Dihedral 14

AAE 451 Team 3 Project Avatar Airfoil Selection Region of Interest Clark Y Airfoil

AAE 451 Team 3 Project Avatar Airfoil Selection Region of Interest Clark Y Airfoil has low drag over range of 15

Section Drag Coefficient Cd Airfoil Selection Section Lift Coefficient Cl AAE 451 Team 3

Section Drag Coefficient Cd Airfoil Selection Section Lift Coefficient Cl AAE 451 Team 3 Project Avatar Angle of Attack (AOA) Section Lift Coefficient Cl 16

AAE 451 Team 3 Project Avatar • • CL needed = 1. 19 Wing

AAE 451 Team 3 Project Avatar • • CL needed = 1. 19 Wing without flaps reaches CL at a=13° Wing stall possible Wing with 15° flap deflection reaches CL at 11° Required CL CL • • Wing Stall Performance Angle of Attack (degrees) Flaperons necessary to meet stall requirements 17

AAE 451 Team 3 Project Avatar CD Wing Performance Required CL at stall CL

AAE 451 Team 3 Project Avatar CD Wing Performance Required CL at stall CL 18

AAE 451 Team 3 Project Avatar Drag Build Up At Cruise Component CD Drag

AAE 451 Team 3 Project Avatar Drag Build Up At Cruise Component CD Drag Wing 0. 018 2. 6 lbf Fuselage 0. 0045 0. 6 lbf Horizontal Tail 0. 0043 0. 6 lbf Vertical Tail 0. 0017 0. 04 lbf 19

AAE 451 Team 3 Project Avatar Wing Operating Parameters CL a (of wing) Flaperon

AAE 451 Team 3 Project Avatar Wing Operating Parameters CL a (of wing) Flaperon Deflection CD L/D Stall 1. 19 11° 15° 0. 119 10 T/O 0. 989 8° 15° 0. 084 12 Cruise 0. 44 2. 8° 0° 0. 018 24 20

AAE 451 Team 3 Project Avatar Dynamics and Controls 21

AAE 451 Team 3 Project Avatar Dynamics and Controls 21

AAE 451 Team 3 Project Avatar Center of Gravity & Aerodynamic Center • Aircraft

AAE 451 Team 3 Project Avatar Center of Gravity & Aerodynamic Center • Aircraft Center of Gravity is 3. 2 ft from nose. – Calculated from CAD program Pro-E • Aircraft Aerodynamic Center is 3. 7 ft from nose. – Position where pitching moment of aircraft doesn’t change with angle of attack – Calculated using Lift from Wing and Horizontal Tail Aerodynamic Center of Gravity 22

AAE 451 Team 3 Project Avatar Static Margin • Desired Static Margin is 15%

AAE 451 Team 3 Project Avatar Static Margin • Desired Static Margin is 15% - 20% – Dependent on C. G. and A. C. location • Static Margin is 15% • Contributes to Horizontal Tail Sizing Aerodynamic Center of Aircraft Static Margin = 15% Center of Gravity Static Margin = 20% 23

AAE 451 Team 3 Project Avatar Horizontal Tail Sizing • Tail sized based on

AAE 451 Team 3 Project Avatar Horizontal Tail Sizing • Tail sized based on desired static margin for static stability and take-off rotation ability – double-dot should be at least 10 deg/sec 2 Ref. Roskam, Airplane Flight Dynamics Area 12 ft 2 Span 6 ft Chord 2 ft 6 ft 24

AAE 451 Team 3 Project Avatar Vertical Tail Sizing • Value of yawing coefficient

AAE 451 Team 3 Project Avatar Vertical Tail Sizing • Value of yawing coefficient due to sideslip angle should Ref. Roskam, Airplane Design be approximately 0. 001 = 10 e-4 • Tail area should be ~2 ft 2 Area 2 ft 2 Span 1 ft Chord 2 ft 1 ft 25

AAE 451 Team 3 Project Avatar Dihedral Angle Recommendations • Survey of Roskam data

AAE 451 Team 3 Project Avatar Dihedral Angle Recommendations • Survey of Roskam data on homebuilt & agricultural low-wing aircraft: ~5° • “Wing and Tail Dihedral for Models” - Mc. Combs – RC w/ailerons (for max maneuverability, low wing): 02° EVD (Equivalent V-Dihedral ≈ dihedral) – Free Flight Scale model low wing: 3 -8° EVD 5° dihedral is a good compromise 26

AAE 451 Team 3 Project Avatar Control Surface Sizing • Sizes calculate from traditional

AAE 451 Team 3 Project Avatar Control Surface Sizing • Sizes calculate from traditional lifting device percentages. Ref. Roskam, Airplane Design Flaperon Elevator Rudder Chord 0. 58 ft 0. 6 ft Inboard Position 0. 95 ft 0. 2 ft 0. 1 ft Outboard Position 7. 2 ft 3 ft 1 ft 0. 6 ft 0. 58 ft 0. 9 ft 6. 25 ft 0. 6 ft 2. 8 ft 27

AAE 451 Team 3 Project Avatar Trimming • Incidence of Horizontal Tail calculated from

AAE 451 Team 3 Project Avatar Trimming • Incidence of Horizontal Tail calculated from trimmed flight during cruise (0 Angle of Attack) • Analysis set incidence at -2 28

AAE 451 Team 3 Project Avatar Structures 29

AAE 451 Team 3 Project Avatar Structures 29

AAE 451 Team 3 Project Avatar Wing Spar Design 2 Spar Design (at. 15

AAE 451 Team 3 Project Avatar Wing Spar Design 2 Spar Design (at. 15 &. 60 chord): • Resist Bending • Assuming 5 -g loading • 53 lbf weight • Safety factor of 1. 5 • Resist Torsion • Less than 1 o twist at tip under normal flight conditions Spar Results: • Material of Choice: Bass or Spruce Wood • Front Spar: • 3. 6” high (based on airfoil) • 0. 37” thick (0. 73” at root) • Rear Spar: • 3” high (based on airfoil) • 0. 16” thick (0. 25” at root) 30

AAE 451 Team 3 Project Avatar Longitudinal Beam Design 2 Beam Design: • Resist

AAE 451 Team 3 Project Avatar Longitudinal Beam Design 2 Beam Design: • Resist Bending from: • 20 lbf payload • Horizontal tail loads • Resist Torsion from: • Rudder deflections • Prop wash over tail Beam Results: • Material of Choice: Bass or Spruce Wood • Beam Dimensions: • 3” high • 0. 25” thick • 8” between the beams 31

AAE 451 Team 3 Project Avatar Tail Structures Foam core with carbon fiber shell

AAE 451 Team 3 Project Avatar Tail Structures Foam core with carbon fiber shell • Horizontal and vertical tails comprised of carbon fiber w/ foam core • Possible to make two foam cores, and cure entire tail at one time • Control surfaces just need to be cut of tail structure • Tail spars allow attach points and transfer load to beams 32

AAE 451 Team 3 Project Avatar Rear Gear Design • Blue lines represent pin

AAE 451 Team 3 Project Avatar Rear Gear Design • Blue lines represent pin joints • Black tie-downs absorb energy from landing • Up to a 33 ft/sec “crash” from 5 feet high • Need 18” relaxed length tie-down • Square aluminum tube transfers landing load to tie-downs and surrounding structure • 1” x 0. 065” thick – 6063 -T 6 33

AAE 451 Team 3 Project Avatar Front Gear Design Aluminum Bolt • Provides pivot

AAE 451 Team 3 Project Avatar Front Gear Design Aluminum Bolt • Provides pivot for gear (does not break) Elastic Band & Nylon Bolt • Elastic Band Absorbs some energy from landing • Nylon bolt breaks during hard landing Front Gear Aluminum Tube • Designed not to break • Designed not to bend • Al tube: 1” x 0. 065” thick 6063 -T 6 34

AAE 451 Team 3 Project Avatar Other Odds and Ends • Covering for Wing:

AAE 451 Team 3 Project Avatar Other Odds and Ends • Covering for Wing: – Coverite 21 st Century Iron on Fabric – 0. 34 oz/ft 2 – Stronger, and resists tears better than Mono. Kote • Covering for Fuselage: Ref. www. towerhobbies. com – Fiberglass • Either mold or foam core • Not conductive – won’t interfere with internal electronics 35

AAE 451 Team 3 Project Avatar Final Weight Estimate 36

AAE 451 Team 3 Project Avatar Final Weight Estimate 36

AAE 451 Team 3 Project Avatar Performance 37

AAE 451 Team 3 Project Avatar Performance 37

AAE 451 Team 3 Project Avatar Aircraft Performance (with 2. 2 lbf fuel) 90

AAE 451 Team 3 Project Avatar Aircraft Performance (with 2. 2 lbf fuel) 90 ft/sec 38

AAE 451 Team 3 Project Avatar Cost 39

AAE 451 Team 3 Project Avatar Cost 39

AAE 451 Team 3 Project Avatar Airframe Cost 40

AAE 451 Team 3 Project Avatar Airframe Cost 40

AAE 451 Team 3 Project Avatar Electronics Cost 41

AAE 451 Team 3 Project Avatar Electronics Cost 41

AAE 451 Team 3 Project Avatar Propulsion Cost 42

AAE 451 Team 3 Project Avatar Propulsion Cost 42

AAE 451 Team 3 Project Avatar Total Aircraft Cost What Purdue Will Pay For

AAE 451 Team 3 Project Avatar Total Aircraft Cost What Purdue Will Pay For This Project 43

AAE 451 Team 3 Project Avatar Total Aircraft Value • Total Aircraft Value =

AAE 451 Team 3 Project Avatar Total Aircraft Value • Total Aircraft Value = (Engineering Pay) + (Cost) + (Value of Already Possessed Parts) • Engineering Pay = 823. 75 hr x $100/hour = $82, 375 • Aircraft Cost = $13, 966. 15 • Value of Already Possessed Parts = $10, 000 – Micropilot = $5, 000 – Carbon Fiber & E-Glass = $5, 000 (estimate) TOTAL AIRCRAFT VALUE = $106, 341. 15 What Purdue Would Pay to Outsource This Project 44

AAE 451 Team 3 Project Avatar Summary 45

AAE 451 Team 3 Project Avatar Summary 45

AAE 451 Team 3 Project Avatar Summary – Internal View Internal Pod Camera View

AAE 451 Team 3 Project Avatar Summary – Internal View Internal Pod Camera View 46

AAE 451 Team 3 Project Avatar Summary – 3 -View 47

AAE 451 Team 3 Project Avatar Summary – 3 -View 47

Summary -Major Design Points AAE 451 Team 3 Project Avatar • Aircraft Description –

Summary -Major Design Points AAE 451 Team 3 Project Avatar • Aircraft Description – – Aspect Ratio = 5 Wing Span = 14. 4 ft Wing Area ~ 42 ft 2 Aircraft Length = 10 ft (not including air data boom) – Engine = 3. 7 hp O. S. 1. 60 FX-FI – Fuel Injected – Weight = 53 lbf • Aircraft Configuration – – – T-Tail Low Wing Pusher High Engine Tricycle Gear Internal Pod 48

AAE 451 Team 3 Project Avatar Questions? 49

AAE 451 Team 3 Project Avatar Questions? 49

AAE 451 Team 3 Project Avatar References (I) • [1] MATLAB. PC Vers 6.

AAE 451 Team 3 Project Avatar References (I) • [1] MATLAB. PC Vers 6. 0. Computer Software. Mathworks, INC. 2001 • [2] Raymer, Daniel P. , Aircraft Design: A Conceptual Approach, AIAA Education Series, 1989. • [3] Roskam, Jan. , Airplane Flight Dynamics and Automatic Flight Controls. Part I. DAR Corporation, Kansas. 2001 • [4] Gere, James M. , Mechanics of Materials. Brooks/Cole, Pacific Grove, CA. 2001 • [5] Tower Hobbies. 9 December 2003. http: //www. towerhobbies. com • [6] XFoil. PC Vers. 6. 94. Computer Software. Mark Drela. 2001. • [7] Niu, Michael C. , Airframe Structural Design, Conmilit Press Ltd. Hong Kong. 1995. • [8] Halliday, et al. , Fundamentals of Physics, John Wiley & Sons. New York. 1997. • [9] Roskam, Jan, Airplane Design (Parts I-VIII), Roskam Aviation and Engineering Corp. Ottawa KS. 1988. • [10] Kuhn, P. , “Analysis of 2 -Spar Cantilever Wings with Special Reference to Torsion and Load Transference”. NACA Report No. 508. • [11] Mc. Master-Carr. 9 December 2003. http: //www. mcmaster. com • [12] Pro/ENGINEER. PC Release 2001. PTC Corporation. • [13] Roskam, Jan. , Methods for Estimating Stability and Control Derivatives of Conventional Subsonic Airplanes. Publisher Jan Roskam. Lawrence, KS. 1977. 50

AAE 451 Team 3 Project Avatar References (II) • [14] Zinger Propeller. 9 December

AAE 451 Team 3 Project Avatar References (II) • [14] Zinger Propeller. 9 December 2003. http: //www. zingerpropeller. com • [15] Mc. Combs, William F. , “Wing and Tail Dihedral for Models”, Model Aviation. Dec. 1994. 104 -112. 51

AAE 451 Team 3 Project Avatar Appendix 52

AAE 451 Team 3 Project Avatar Appendix 52

SIZING

SIZING

AAE 451 Team 3 Project Avatar Cruise Speed 54

AAE 451 Team 3 Project Avatar Cruise Speed 54

AAE 451 Team 3 Project Avatar Stall Speed 55

AAE 451 Team 3 Project Avatar Stall Speed 55

AAE 451 Team 3 Project Avatar Climb Angle 56

AAE 451 Team 3 Project Avatar Climb Angle 56

AAE 451 Team 3 Project Avatar Ceiling 57

AAE 451 Team 3 Project Avatar Ceiling 57

AAE 451 Team 3 Project Avatar Endurance 58

AAE 451 Team 3 Project Avatar Endurance 58

AAE 451 Team 3 Project Avatar Takeoff 59

AAE 451 Team 3 Project Avatar Takeoff 59

AAE 451 Team 3 Project Avatar Landing Distance 60

AAE 451 Team 3 Project Avatar Landing Distance 60

PROP

PROP

AAE 451 Team 3 Project Avatar Appendix • OS 1. 60 FX-FI • Consistency:

AAE 451 Team 3 Project Avatar Appendix • OS 1. 60 FX-FI • Consistency: The Fuel Injection system constantly supplies the correct air/fuel mixture to the engine, regardless of speed, altitude, or attitude. • Recommended is a 450 -550 cc fuel tank that allows approximately 10 to 12 minute flights. = 30 min. with 50 oz. tank. 62

AERO

AERO

AAE 451 Team 3 Project Avatar Aerodynamic Modeling Prandtl’s Lifting line theory used for

AAE 451 Team 3 Project Avatar Aerodynamic Modeling Prandtl’s Lifting line theory used for aerodynamic modeling of the lifting components Solving Prandt’s equation Substituting: Equation to solve: Main Results CL = πAR*A 1*(α- αLo) • System of N equations with N unknowns (Solve N N matix) • Take N different spanwise locations on the wing where the equation is to be satisfied: 1, 2, . . N; (but not at the tips, so: 0 < < ) • The wing is symmetrical A 2, A 4, … are zero • Take only A 1, A 3, … as unknowns • Take only control points on half of the wing: 0 < i /2 64

AAE 451 Team 3 Project Avatar Choice of main wing airfoil From lifting line

AAE 451 Team 3 Project Avatar Choice of main wing airfoil From lifting line with Initial parameters: • Rectangular planform, 1000 ft • a 0 = 2 pi, • αL 0 = 0, • AR = 5; • W/S = 1. 28 (from sizing) • CL = 0. 4437 Cl distribution found at cruise Cl varies : 0 to 0. 58 Taking into account the Cl variation above, the need of an airfoil with a drag bucket at the specified Cl’s Xfoil utilized for different foils at the above conditions 65

AAE 451 Team 3 Project Avatar Airfoil Selection Region of Interest Clark Y Airfoil

AAE 451 Team 3 Project Avatar Airfoil Selection Region of Interest Clark Y Airfoil Drag Bucket location 66

AAE 451 Team 3 Project Avatar Clark. Y foil Xfoil runs of Clark. Y

AAE 451 Team 3 Project Avatar Clark. Y foil Xfoil runs of Clark. Y foil at cruise and take-off Cruise: Takeoff no flap: Takeoff 10 deg flap: Takeoff 15 deg flap: αL= -3. 5 deg αL= -3. 8 deg αL= -7. 8 deg In lifting Line Equation: a 0 – updated depending on condition αL - updated according to above 67

AAE 451 Team 3 Project Avatar • • Stall Performance CL needed = 1.

AAE 451 Team 3 Project Avatar • • Stall Performance CL needed = 1. 19 Wing without flaps reaches CL at 13 deg aoa Wing stall possible Wing with 15 deg flap deflection reaches CL at 11 degrees Required CL Flaperons necessary to meet stall requirements 68

AAE 451 Team 3 Project Avatar Stall Performance Drag Calculation CDtotal = CDinduced+CDvisc CDinduced

AAE 451 Team 3 Project Avatar Stall Performance Drag Calculation CDtotal = CDinduced+CDvisc CDinduced – from Lifting line CD visc – integrated at the found Cls Required CL CD = 0. 119 at required CL 69

AAE 451 Team 3 Project Avatar Cruise Performance CL needed = 0. 44 Total

AAE 451 Team 3 Project Avatar Cruise Performance CL needed = 0. 44 Total Lift produced = 57 lbf CL achieved at 2. 8 deg Total Drag = 2. 6 lbf, L/D =21 70

AAE 451 Team 3 Project Avatar Operating Parameters CL Aoa Flap Deflection CD L/D

AAE 451 Team 3 Project Avatar Operating Parameters CL Aoa Flap Deflection CD L/D Stall 1. 19 11 deg 15 deg 0. 119 10 T/O 0. 989 8. deg 15 deg 0. 084 12 Cruise 0. 44 2. 8 deg 0. 018 24 71

D & C

D & C

AAE 451 Team 3 Project Avatar Center of Gravity • Center of Gravity of

AAE 451 Team 3 Project Avatar Center of Gravity • Center of Gravity of Aircraft – Weight of Horizontal Tail changes with area Note: 0. 44 lbs/ft 2 based on aircraft sizing code 73

AAE 451 Team 3 Project Avatar Aerodynamic Center • Aerodynamic Center as a function

AAE 451 Team 3 Project Avatar Aerodynamic Center • Aerodynamic Center as a function of Horizontal Tail Area Roskam Eq 11. 1 Raymer Fig 16. 12 74

AAE 451 Team 3 Project Avatar Takeoff Rotation Equation • This sizing based on

AAE 451 Team 3 Project Avatar Takeoff Rotation Equation • This sizing based on angular acceleration during take-off rotation Ref. Roskam 421 book, pg 288 -290 Variable definitions found in above reference 75

AAE 451 Team 3 Project Avatar Yaw Moment due to Sideslip • Vertical Tail

AAE 451 Team 3 Project Avatar Yaw Moment due to Sideslip • Vertical Tail sized from Coefficient of Yaw Moment due to Sideslip Roskam Eq 11. 8 Vol 2 Due to Wing and Fuselage: Roskam Eq 10. 42 Vol 6 76

AAE 451 Team 3 Project Avatar Dihedral Angle EVD = A + k. B

AAE 451 Team 3 Project Avatar Dihedral Angle EVD = A + k. B CL X A = 0° k = f(x/(b/2)) = 0. 98 B = EVD / k ≈ EVD B A=0° Ref. Mc. Combs, William F. “Wing and Tail Dihedral for Models. ” 77

AAE 451 Team 3 Project Avatar Dynamics Short Period Mode Phugoid Mode Pole -14.

AAE 451 Team 3 Project Avatar Dynamics Short Period Mode Phugoid Mode Pole -14. 391 ± 1. 0079 i Pole -0. 078823 ± 0. 71828 i Natural Frequency 14. 431 (rad/s) Natural Frequency 0. 72259 (rad/s) Damping Ratio 0. 99721 Damping Ratio 0. 10908 Dutch Roll Mode Spiral Mode Pole -1. 1607 ± 2. 4427 i Pole Natural Frequency 2. 7045 (rad/s) Damping Ratio 0. 42918 0. 29086 Roll Mode Pole Ref. Purdue University AAE 565, Matlab Predator Code -25. 748 78

STRUCTURE S

STRUCTURE S

AAE 451 Team 3 Project Avatar What Materials to Use Titanium Bass / Spruce

AAE 451 Team 3 Project Avatar What Materials to Use Titanium Bass / Spruce 80

AAE 451 Team 3 Project Avatar Material Properties Titanium = difficult to obtain Wood

AAE 451 Team 3 Project Avatar Material Properties Titanium = difficult to obtain Wood = not difficult to obtain Ref. 1999 Forest Products Laboratory Wood Handbook Ref. www. towerhobbies. com 81

AAE 451 Team 3 Project Avatar Twist Constraint (<1 o) Ref. Kuhn pg. 49

AAE 451 Team 3 Project Avatar Twist Constraint (<1 o) Ref. Kuhn pg. 49 Where T = Torque (in-lbf) L = Length (in) l = f(B 0, A 0) (ref. Appendix) A 0 = f(E, I) (ref. Appendix) B 0 = f(G, J) (ref. Appendix) E = Young’s Modulus (psi) I = Moment of Inertia (in 4) G = Torsional Stiffness (psi) J = Polar Moment of Inertia (in 4) Ref. Gere Assumptions: Small Deflections Spars & Ribs Carry all Torsion Span ~ 14. 4 ft Chord ~ 2. 9 ft Safety Factor = 1. 5 G-Loading = 5. 0 Weight = 53 lbs 82

AAE 451 Team 3 Project Avatar Twist at Tip 83

AAE 451 Team 3 Project Avatar Twist at Tip 83

AAE 451 Team 3 Project Avatar Twist at Tip (Zoom) Chosen Front Spar =

AAE 451 Team 3 Project Avatar Twist at Tip (Zoom) Chosen Front Spar = 0. 73” thick Chosen Rear Spar = 0. 25” thick (note, this doesn’t include the step) 84

AAE 451 Team 3 Project Avatar Deflection at Tip Load (lbf) Ref. Gere pg.

AAE 451 Team 3 Project Avatar Deflection at Tip Load (lbf) Ref. Gere pg. 892 Where Load = Weight*SF*G-loading (lbf) L = Length (in) a (in) L (in) E = Young’s Modulus (psi) I = Moment of Inertia (in 4) For this design: a ~ 3 ft or 36 in (based on span-wise lift distribution) Assumptions: Small Deflections NO TORSION Span ~ 14. 4 ft Chord ~ 2. 9 ft Safety Factor = 1. 5 G-loading = 5. 0 Weight = 53 lbs 85

AAE 451 Team 3 Project Avatar Deflection at Tip Chosen Spar Configuration 86

AAE 451 Team 3 Project Avatar Deflection at Tip Chosen Spar Configuration 86

AAE 451 Team 3 Project Avatar Is Stress too High? Load (lbf) Ref. Gere

AAE 451 Team 3 Project Avatar Is Stress too High? Load (lbf) Ref. Gere pg. 323 Where M = Weight*SF*G-loading*a (in-lbf) y = Maximum Dist from Neutral Axis (in) a (in) L (in) I = Moment of Inertia (in 4) For this design: a = 3 ft or 36 in (based on span-wise lift distribution) Assumptions: Span ~ 14. 4 ft Chord ~ 2. 9 ft Safety Factor = 1. 5 G-loading = 5. 0 Weight = 53 lbs 87

AAE 451 Team 3 Project Avatar Max Tension Stress 88

AAE 451 Team 3 Project Avatar Max Tension Stress 88

AAE 451 Team 3 Project Avatar Max Compression Stress 89

AAE 451 Team 3 Project Avatar Max Compression Stress 89

AAE 451 Team 3 Project Avatar Covering • Traditional Monocote may not be strong

AAE 451 Team 3 Project Avatar Covering • Traditional Monocote may not be strong enough for these large aircraft • Coverite 21 st Century Iron on Fabric is stronger, and resists tears much better – 0. 34 oz/ft 2 – Approx. 2 lbs for entire wing Ref. www. towerhobbies. com 90

AAE 451 Team 3 Project Avatar Summary • Main Wing – Spruce or Bass

AAE 451 Team 3 Project Avatar Summary • Main Wing – Spruce or Bass wood – Front Spar h • 0. 73” thick by 3. 6” high – Rear Spar • 3/8” thick by 3” high t 91

AAE 451 Team 3 Project Avatar Rear View of Tail • NOTES • Torsion

AAE 451 Team 3 Project Avatar Rear View of Tail • NOTES • Torsion can effectively be reduced with appropriate beam spacing • Bending can be reduced by increasing moment of inertia of beams (not spacing) Side force from Vstab creates torsion effect on beams • Some torsion is inherent, torsion can not be negated as it could in wing Downward force from H-stab creates bending moment on beams 92

AAE 451 Team 3 Project Avatar Deflection at Tip (Rear of Tail) Load (lbf)

AAE 451 Team 3 Project Avatar Deflection at Tip (Rear of Tail) Load (lbf) Ref. Gere pg. 892 L (in) Where Load = (lbf) L = Length (in) E = Young’s Modulus (psi) I = Moment of Inertia (in 4) Moment of inertia of rectangular beam: I (in 4) = (t)(h 3)/12 t and h shown on next slide Assumptions: Small Deflections Safety Factor = 1. 5 G-loading = 3. 0 Rectangular Beams Current Known Values: L = 6. 2 ft Load ~ 8 lbf 93

AAE 451 Team 3 Project Avatar Deflection at Tip (Rear of Tail) Green =

AAE 451 Team 3 Project Avatar Deflection at Tip (Rear of Tail) Green = spruce Black = bass h h=2 in t h=3 in 94

AAE 451 Team 3 Project Avatar Deflection at Tip (Rear of Tail) Green =

AAE 451 Team 3 Project Avatar Deflection at Tip (Rear of Tail) Green = spruce Black = bass h h=2 in t h=3 in Required t ~0. 55 in 95

AAE 451 Team 3 Project Avatar Landing Gear Placement (I) θ = tipback angle

AAE 451 Team 3 Project Avatar Landing Gear Placement (I) θ = tipback angle = Landing gear placement based on guidelines found in Raymer 96

AAE 451 Team 3 Project Avatar Landing Gear Placement (II) γ = overturn angle

AAE 451 Team 3 Project Avatar Landing Gear Placement (II) γ = overturn angle = Landing gear placement based on guidelines found in Raymer 97

AAE 451 Team 3 Project Avatar Easily Obtainable Square Tubing Ref. www. mcmaster. com

AAE 451 Team 3 Project Avatar Easily Obtainable Square Tubing Ref. www. mcmaster. com 98

AAE 451 Team 3 Project Avatar Buckling of Rear Gear Load Ref. Gere pg.

AAE 451 Team 3 Project Avatar Buckling of Rear Gear Load Ref. Gere pg. 763 L Where L = Length (in) E = Young’s Modulus (psi) I = Moment of Inertia (in 4) A = Cross Sectional Area (in 2) For Rear Gear: L ~ 15. 3 in Load Assumptions: Pinned-Pinned Column 1 st Mode Buckling No Eccentricity 99

AAE 451 Team 3 Project Avatar Compressive Failure of Rear Gear Load Ref. MIL-HDBK-5

AAE 451 Team 3 Project Avatar Compressive Failure of Rear Gear Load Ref. MIL-HDBK-5 H: 3 -255 Where Load = (Weight)(S. F. )(Gloading) A = Cross Sectional Area (in 2) L Load Assumptions: Weight = 53 lbf Gloading = 10 S. F. = 1. 5 Aluminum 6061 -T 6 No Buckling 100

AAE 451 Team 3 Project Avatar Stress on Rear Gear Smallest easily obtainable tubing:

AAE 451 Team 3 Project Avatar Stress on Rear Gear Smallest easily obtainable tubing: 1” x 0. 062” t=0. 125” 101

AAE 451 Team 3 Project Avatar Great, what about the bungee? • Consider worst

AAE 451 Team 3 Project Avatar Great, what about the bungee? • Consider worst reasonable landing situation – Moving at (1. 1)Vstall – 5 feet above ground – Aircraft falls out of the sky • Can the bungee absorb the energy associated with this landing? 102

AAE 451 Team 3 Project Avatar Great, what about the bungee? Assumptions: Weight =

AAE 451 Team 3 Project Avatar Great, what about the bungee? Assumptions: Weight = 53 lbf Vstall = 30 ft/sec Altitude = 5 ft • Don’t want x to exceed 3 inches (beyond initial stretch) on landing 103

AAE 451 Team 3 Project Avatar What Spring Constant is Needed? Required k ~

AAE 451 Team 3 Project Avatar What Spring Constant is Needed? Required k ~ 3. 75 lbf/in 1/k ~ 0. 266 in/lbf 104

AAE 451 Team 3 Project Avatar What is the Spring Constant? Relaxed Length ~18

AAE 451 Team 3 Project Avatar What is the Spring Constant? Relaxed Length ~18 inches 105

AAE 451 Team 3 Project Avatar How Big is the Bolt? Ref. Gere pg

AAE 451 Team 3 Project Avatar How Big is the Bolt? Ref. Gere pg 900 Load If load = (Weight)(S. F. )(Gloading) = 795 lbf Reaction = 1770 lbf (instantaneous) Need cross sectional area of bolt to be 0. 197 Reaction in 2 Diameter of nylon bolt = 0. 5 in Assumptions: Weight = 53 lbf Gloading = 10 S. F. = 1. 5 3. 1” 6. 9” 106

PERFORMAN CE

PERFORMAN CE

AAE 451 Team 3 Project Avatar Endurance • Endurance = Fuel / Consumptionfuel •

AAE 451 Team 3 Project Avatar Endurance • Endurance = Fuel / Consumptionfuel • Avg. Engine Fuel Consumption = 45. 455 m. L/min • Endurance = 30 min 108

AAE 451 Team 3 Project Avatar Range Since this is RC, assume almost instaneous

AAE 451 Team 3 Project Avatar Range Since this is RC, assume almost instaneous cruise conditions L/D = 19 Cbhp = 1. 5 lb/hr/bhp Prop eff =. 67 Fuel Frac = 1. 043 109

AAE 451 Team 3 Project Avatar Minimum Flight Velocitymin= 29. 95 ft/sec Weight =

AAE 451 Team 3 Project Avatar Minimum Flight Velocitymin= 29. 95 ft/sec Weight = 53 lbf CLmax = 1. 19 q =1. 067 lbf/ft^2 110

AAE 451 Team 3 Project Avatar Rate of Climb Vv= 7. 5 ft/sec D

AAE 451 Team 3 Project Avatar Rate of Climb Vv= 7. 5 ft/sec D = 6. 5 lbf hpengine = 3. 7 hp W = 53 lbf V = 33 ft/sec Prop Eff =. 3 111

AAE 451 Team 3 Project Avatar Maximum Velocity Thrust/Drag [lbf] Thrust Drag Flying Velocity

AAE 451 Team 3 Project Avatar Maximum Velocity Thrust/Drag [lbf] Thrust Drag Flying Velocity [ft/s] 112

AAE 451 Team 3 Project Avatar Climb Angle Vv = 7. 5 ft/sec V

AAE 451 Team 3 Project Avatar Climb Angle Vv = 7. 5 ft/sec V = 33 ft/sec 113