DEPARTAMENTO DE CINCIA E TECNOLOGIA AEROESPACIAL INSTITUTO TECNOLGICO

DEPARTAMENTO DE CIÊNCIA E TECNOLOGIA AEROESPACIAL INSTITUTO TECNOLÓGICO DE AERONÁUTICA DIVISÃO DE ENGENHARIA AERONÁUTICA

Aerodynamics AED Geometry Aerodynamic forces

Aerodynamic Design Airfoils Surfaces L/D ~ 50 L/D ~ 25 Aircraft L/D ~ 10

Types of airfoils Symmetrical airfoils Cambered airfoils NACA 0012 RG 14 High-lift airfoils Selig

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL Lift curve CL

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL stall Raymer, 1992

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL Drag polar CL

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL L/D curve CM

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL Moment curve CM

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL

Camber NACA 0012 Re 3 e 5 XFOIL NACA 2412 Re 3 e 5

Thickness NACA 0012 Re 3 e 5 XFOIL NACA 0015 Re 3 e 5

Thickness Zoom!!! NACA 0012 Re 3 e 5 XFOIL NACA 0015 Re 3 e

High-lift airfoils Eppler 420 Xfoil Eppler 420 gf 03 Fluent Selig 1223 Xfoil Re

Manufacturing Lift Moment Xfoil Olafesky 02 Selig 1223 Tunnel lower same cclmax Re=2· 105

Wings Airfoil = Infinite wing Finite wing . . . 2 D aerodynamics 3

Induced Drag LIFT More lift Greater vortices MORE DRAG

Induced Drag NACA 2412 airfoil Re 3 e 5 XFOIL NACA 2412 wing Re

Induced Drag parasite drag induced drag NACA 2412 airfoil Re 3 e 5 XFOIL

Induced Drag parasite drag induced drag airfoil planform NACA 2412 airfoil Re 3 e

Aspect Ratio NACA 2412 wing Re 3 e 5; AR=4 Non-linear LLT NACA 2412

Taper ratio NACA 2412 wing Re 3 e 5; AR=6; l=1. 0 Non-linear LLT

Taper ratio LIFT ~ NACA 2412 wing Re 3 e 5; AR=6; l=1. 0

Taper ratio More taper increases loading at the root better for structures LIFT ~

Taper ratio • Comparison with rectangular wing: – Induced drag reduced by 6%. –

http: //www. homebuiltairplanes. com/f Stall progression

Bodies Aerodesign ITA Micro 2011 fuselage Upper view Side view

Bodies Aerodesign ITA Micro 2011 fuselage Upper view Side view NOSE MAIN SECTION TAIL

Bodies Aerodesign ITA Micro 2011 fuselage Upper view Side view Avoid angles greater than

Bodies Avoid angles greater than 15 degrees

Corners Girardi, Cavalieri, Araújo, COBEM 2007 Rounded corner: 20% less drag

Trim WING LIFT WING MOMENT TAIL LIFT CG AIRPLANE LIFT = WING LIFT -

Interference drag Wing CD, wing Fuselage CD, fus Wing+Fuselage CD, wf

Interference drag Wing CD, wing + CD, fus Fuselage CD, fus CD, wf Wing+Fuselage

Interference drag Wing CD, wing Fuselage CD, fus CD, wing + CD, fus <

Interference drag www. attawayair. com Fairings en. wikipedia. org www. westmiddlesexmodellers. co. uk

Full configuration aerodynamics Selig 1223 airfoil Re 2 e 5 XFOIL Regular 2012 wing

Performance Mission requirements Aerodynamic model Performance MTOW Propulsive model

Mission 1 -Takeoff 2 -Climb 3 -Curve 3 5 6 4 4 4 -Cruise

Stall speed High wing loading airplane should fly faster!!!

Takeoff Requirement!!! Constant acceleration model Normal (N) Friction (Fat) Thrust (T) Weight (W) Requirement!!!

Takeoff • After some math. . . • To reduce the takeoff distance: –

Climb Lift (L) Thrust (T) Requirement!!! Drag (D) Weight (W) small

Climb • After some math. . . • To increase the climb gradient: –

Performance Summary PHASE TAKEOFF CLIMB xdec < 70 m g > 0. 06 REQUIREMENT

Review • Aerodynamics – Airfoil camber and thickness – Surface aspect ratio, taper ratio

Outros perfis • UIUC Airfoil Coordinates Database (Selig et al. ) • http: //m-selig.

Slides: 93

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DEPARTAMENTO DE CIÊNCIA E TECNOLOGIA AEROESPACIAL INSTITUTO TECNOLÓGICO DE AERONÁUTICA DIVISÃO DE ENGENHARIA AERONÁUTICA DEPARTAMENTO DE PROJETOS DE AERONAVES PRJ – 30 Projeto e Construção de Aeromodelos Unit 3/8 Aerodynamics & Performance Prof. Adson Agrico Prof. Vitor Kleine São José dos Campos, SP, Brazil – March, 2016

Schedule Aerodynamics Performance

Aerodynamics AED Geometry Aerodynamic forces

Aerodynamic Forces

Aerodynamic Design Airfoils Surfaces L/D ~ 50 L/D ~ 25 Aircraft L/D ~ 10 Bodies L/D ~ 3

Airfoil geometry

Types of airfoils Symmetrical airfoils Cambered airfoils NACA 0012 RG 14 High-lift airfoils Selig 1223 Reflex airfoils Eppler 325 Want more? : UIUC Airfoil Data Site

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL Lift curve CL vs a

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL stall Raymer, 1992 Lift curve CL vs a

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL Drag polar CL vs CD

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL L/D curve CM vs a

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL Moment curve CM vs a

Main curves MH 32 airfoil Re 4. 4 e 5 XFOIL

Camber NACA 0012 Re 3 e 5 XFOIL NACA 2412 Re 3 e 5 XFOIL

Thickness NACA 0012 Re 3 e 5 XFOIL NACA 0015 Re 3 e 5 XFOIL

Thickness Zoom!!! NACA 0012 Re 3 e 5 XFOIL NACA 0015 Re 3 e 5 XFOIL

Thickness NACA 0012 Re 3 e 5 XFOIL NACA 0015 Re 3 e 5 XFOIL

High-lift airfoils Eppler 420 Xfoil Eppler 420 gf 03 Fluent Selig 1223 Xfoil Re = 3 e 5

Reynolds number sd 7062

Manufacturing Lift Moment Xfoil Olafesky 02 Selig 1223 Tunnel lower same cclmax Re=2· 105

Aerodynamic Design Airfoils Surfaces L/D ~ 50 L/D ~ 25 Aircraft L/D ~ 10 Bodies L/D ~ 3

Wings Airfoil = Infinite wing Finite wing . . . 2 D aerodynamics 3 D aerodynamics

Induced drag

Induced Drag LIFT More lift Greater vortices MORE DRAG

Induced Drag en. wikipedia. org

Induced Drag NACA 2412 airfoil Re 3 e 5 XFOIL NACA 2412 wing Re 3 e 5; AR=6 Non-linear LLT

Induced Drag parasite drag induced drag NACA 2412 airfoil Re 3 e 5 XFOIL NACA 2412 wing Re 3 e 5; AR=6 Non-linear LLT

Induced Drag parasite drag induced drag airfoil planform NACA 2412 airfoil Re 3 e 5 XFOIL NACA 2412 wing Re 3 e 5; AR=6 Non-linear LLT

Induced Drag Highly Cambered Airfoil

Aspect Ratio NACA 2412 wing Re 3 e 5; AR=4 Non-linear LLT NACA 2412 wing Re 3 e 5; AR=6 Non-linear LLT NACA 2412 wing Re 3 e 5; AR=8 Non-linear LLT

Taper ratio NACA 2412 wing Re 3 e 5; AR=6; l=1. 0 Non-linear LLT NACA 2412 wing Re 3 e 5; AR=6; l=0. 5 Non-linear LLT NACA 2412 wing Re 3 e 5; AR=6; l=0. 1 Non-linear LLT

Taper ratio LIFT ~ NACA 2412 wing Re 3 e 5; AR=6; l=1. 0 Non-linear LLT NACA 2412 wing Re 3 e 5; AR=6; l=0. 5 Non-linear LLT NACA 2412 wing Re 3 e 5; AR=6; l=0. 1 Non-linear LLT

Taper ratio More taper increases loading at the root better for structures LIFT ~ NACA 2412 wing Re 3 e 5; AR=6; l=1. 0 Non-linear LLT NACA 2412 wing Re 3 e 5; AR=6; l=0. 5 Non-linear LLT NACA 2412 wing Re 3 e 5; AR=6; l=0. 1 Non-linear LLT

Taper ratio • Comparison with rectangular wing: – Induced drag reduced by 6%. – Manufacturing time doubles. 75 man-hours 150 man-hours

Sweep Raymer, 1992

Sweep M=0. 3 Raymer, 1992

Sweep Raymer, 1992

http: //www. homebuiltairplanes. com/f Stall progression

Wingtip devices Raymer, 1992

Aerodynamic Design Airfoils Surfaces L/D ~ 50 L/D ~ 25 Aircraft L/D ~ 10 Bodies L/D ~ 3

Bodies

Bodies Fineness ratio

Bodies BAD. . . GOOD!!!

Bodies Aerodesign ITA Micro 2011 fuselage Upper view Side view

Bodies Aerodesign ITA Micro 2011 fuselage Upper view Side view NOSE MAIN SECTION TAIL CONE

Bodies Aerodesign ITA Micro 2011 fuselage Upper view Side view Avoid angles greater than 15 degrees

Bodies Avoid angles greater than 15 degrees

Corners Girardi, Cavalieri, Araújo, COBEM 2007 Rounded corner: 20% less drag

Aerodynamic Design Airfoils Surfaces L/D ~ 50 L/D ~ 25 Aircraft L/D ~ 10 Bodies L/D ~ 3

Trim

Trim WING LIFT WING MOMENT TAIL LIFT CG AIRPLANE LIFT = WING LIFT - TAIL LIFT

Interference drag Wing CD, wing Fuselage CD, fus Wing+Fuselage CD, wf

Interference drag Wing CD, wing + CD, fus Fuselage CD, fus CD, wf Wing+Fuselage CD, wf

Interference drag Wing CD, wing Fuselage CD, fus CD, wing + CD, fus < CD, wf Wing+Fuselage CD, wf

Interference drag Micro 2010

Interference drag www. attawayair. com Fairings en. wikipedia. org www. westmiddlesexmodellers. co. uk

Full configuration aerodynamics Selig 1223 airfoil Re 2 e 5 XFOIL Regular 2012 wing Re 3. 7 e 5 AVL + Aerowiz Regular 2012 Re 3. 7 e 5 AVL + Aerowiz

Who cares?

Aerodynamic Design Airfoils Surfaces L/D ~ 50 L/D ~ 25 Aircraft L/D ~ 10 Bodies L/D ~ 3

Schedule Aerodynamics Performance

Performance Mission requirements Aerodynamic model Performance MTOW Propulsive model

Mission 1 -Takeoff 2 -Climb 3 -Curve 3 5 6 4 4 4 -Cruise 5 -Descent 6 -Go around 7 -Landing 7 1 2 3

Stall speed

Stall speed High wing loading airplane should fly faster!!!

Takeoff Requirement!!! Constant acceleration model Normal (N) Friction (Fat) Thrust (T) Weight (W) Requirement!!!

Takeoff • After some math. . .

Takeoff • After some math. . . • To reduce the takeoff distance: – Increase wing area. – Increase CLmax. airfoil planform

Climb Lift (L) Thrust (T) Requirement!!! Drag (D) Weight (W) small

Climb • After some math. . .

Climb • After some math. . . • To increase the climb gradient: – Increase the aerodynamic efficiency. airfoil planform

Performance Summary PHASE TAKEOFF CLIMB xdec < 70 m g > 0. 06 REQUIREMENT (3. 5°) ks = 1. 1 Increase CLmax GOALS Increase L/D Increase S

Trade-off Re: 2 e 5 - 3 e 5

Review • Aerodynamics – Airfoil camber and thickness – Surface aspect ratio, taper ratio and sweep – Bodies fineness ratio and angles – Aircraft trim and interference drag • Performance – Stall speed wing loading – Takeoff CLmax and wing loading – Climb aerodynamic efficiency

Alguns Perfis

Outros perfis • UIUC Airfoil Coordinates Database (Selig et al. ) • http: //m-selig. ae. illinois. edu/ads/coord_database. html