AE-705: Introduction to Flight AIRFOILS Shishir Damani Mechanical Engineering Department NIT Tiruchirappalli AE-705 Introduction to Flight Lecture 07 Capsule-04
OVERVIEW What is an Airfoil? Airfoil Terminologies and Nomenclature History of Airfoil Types of Airfoils Flat Plate and Cambered Airfoil Thick Airfoil Laminar Airfoil Low Reynolds Number Airfoil Supersonic Airfoil Supercritical Airfoil Modern Developments AE-705 Introduction to Flight Lecture 07 Capsule-04
Foil paper in air!! WHAT IS AN AIRFOIL? AE-705 Introduction to Flight Lecture 07 Capsule-04
X section of the wing normal to span Airfoil AE-705 Introduction to Flight Lecture 07 Capsule-04
Airfoil Terminology AE-705 Introduction to Flight Lecture 07 Capsule-04
Airfoils belong to families too ! AIRFOIL NOMENCLATURE AE-705 Introduction to Flight Lecture 07 Capsule-04
NACA 4, 5, 6, 7 & 8 series Beech series Bell family RAF series SERI family Antonov family Gottingen series Boeing series Eppler family Lieback family Clark family KFM series Wortmann series NASA family TsAGI family GAW series BAC family Lissaman series AE-705 Introduction to Flight Lecture 07 Capsule-04
SERI NOMENCLATURE S olar E nergy R esearch I nstitute Advanced wind turbine blades Control peak rotor power (high winds) Produce power in Medium winds also Source: Research paper on SERI Advance Wind Turbine Blades by J. Tangier, B. Smith, D. Jager AE-705 Introduction to Flight Lecture 07 Capsule-04
KLINE FOGLEMAN AIRFOIL Devised ~ 50 years ago Poor lift-to-drag ratio Used in RC airplanes AE-705 Introduction to Flight Lecture 07 Capsule-04
AE-705 Introduction to Flight Lecture 07 Capsule-04
GOTTINGEN AIRFOIL Created at Gottingen University,Germany~1910s There are one, two and three digit numbers What ’s the relation ?? Source: http://www.aerospaceweb.org/question/airfoils/q0197.shtml Gottingen 622 AE-705 Introduction to Flight Lecture 07 Capsule-04
EPPLER AIRFOIL Design based on conformal-mapping Considered velocity distribution Source: https://en.wikipedia.org/wiki/Conformal_map#/ For details: https://www.youtube.com /watch?v=woBgZMtiAeI media/File:Conformal_map.svg Function which preserves angles locally AE-705 Introduction to Flight Lecture 07 Capsule-04
Who was behind all this?? AIRFOIL HISTORY AE-705 Introduction to Flight Lecture 07 Capsule-04
A VISIT TO THE PAST AE-705 Introduction to Flight Lecture 07 Capsule-04
1849 ; Gliders flown by Sir George Cayley Scientific reasoning on cambered airfoil 1884 Further studied and developed by Jean Marie Le Bris, John J. Montgomery, Otto Lilienthal, Percy Pilcher, Octave Chanute and Augustus Moore Herring AE-705 Introduction to Flight Lecture 07 Capsule-04
Sir George Cayley first glider AE-705 Introduction to Flight Lecture 07 Capsule-04
Lilienthal Ornithopter AE-705 Introduction to Flight Lecture 07 Capsule-04
Wright Brothers developed three gliders In July 1899 Wilbur tested wing warping 1901 glider larger wing area Stalled a few times Forward elevator Phewwww!!! Source: https://en.wikipedia.org/wiki/Wright_brothers#Flights AE-705 Introduction to Flight Lecture 07 Capsule-04
Thin Airfoils WTT at low speed At low speeds Early WTT misleading!! most flow remained attached but was separated in reality AE-705 Introduction to Flight Lecture 07 Capsule-04
AE-705 Introduction to Flight Lecture 07 Capsule-04
Let’s see what this has to give us?? TYPES OF AIRFOILS AE-705 Introduction to Flight Lecture 07 Capsule-04
Seriously!!!!! FLAT PLATE AE-705 Introduction to Flight Lecture 07 Capsule-04
WHY NOT USE FLAT PLATES? Flat Plates cannot produce Lift ? AE-705 Introduction to Flight Lecture 07 Capsule-04
Air flow speed and static pressure Lift Camber changes V and P laminar flow Most wings are designed with this concept η of the airfoil AE-705 Introduction to Flight Lecture 07 Capsule-04
EFFECT OF CAMBER ON LIFT Source: https://www.quora.com/Why-are-thick-airfoils-useful-Are-they-for-generating-lift-at-low-airspeeds AE-705 Introduction to Flight Lecture 07 Capsule-04
EFFECT OF CAMBER ON LIFT AE-705 Introduction to Flight Lecture 07 Capsule-04
EFFECT OF CAMBER ON LIFT Source: https://www.quora.com/Why-are-thick-airfoils-useful-Are-they-for-generating-lift-at-low-airspeeds AE-705 Introduction to Flight Lecture 07 Capsule-04
EFFECT OF CAMBER ON LIFT AE-705 Introduction to Flight Lecture 07 Capsule-04
EFFECT OF CAMBER ON LIFT Powerful engines Focus on L/D ratio ( L) Drag aerodynamic characteristic Source: https://www.quora.com/Why-are-thick-airfoils-useful-Are-they-for-generating-lift-at-low-airspeeds AE-705 Introduction to Flight Lecture 07 Capsule-04
Source: https://backcountrypilot.org/forum/horizontal- stabilizer-shape-air-foil-vs-flat-pros-cons-18170 Are these stuffed up?? THICK AIRFOILS AE-705 Introduction to Flight Lecture 07 Capsule-04
Thin airfoils stall at α Separation of the flow over the top surface creates drag loss of lift I have a mathematical model Larger LE radii Higher α before stall Ludwig Prandtl (1875-1953) AE-705 Introduction to Flight Lecture 07 Capsule-04
L Thicker airfoils flow separation till α German engineers planes climbed faster and maneuver more sharply Source: http://www.aviation-history.com/articles/great-war.htm AE-705 Introduction to Flight Lecture 07 Capsule-04
L Thicker airfoils flow separation till α German engineers planes climbed faster and maneuver more sharply Benefits; more space for: Fuel tanks Space for LG Source: https://www.quora. com /How-can-wings-of-aircraft-store-fuel AE-705 Introduction to Flight Lecture 07 Capsule-04
L Thicker airfoils flow separation till α German engineers planes climbed faster and maneuver more sharply Benefits; more space for: Fuel tanks Space for LG Structural spar Source: https://www.quora. com /How-can-wings-of-aircraft-store-fuel Source: http://www.clubhyper.com/reference/fw190landinggear_1.htm Source: http://www.darkgovernment.com/RANCHO/CRASH/TWA/WINGBOX/wingbox.gif AE-705 Introduction to Flight Lecture 07 Capsule-04
Some Airplanes with their Airfoils AE-705 Introduction to Flight Lecture 07 Capsule-04
So they don’t have turbulence? LAMINAR AIRFOIL AE-705 Introduction to Flight Lecture 07 Capsule-04
Source: https://blog.rescale.com/leveraging-rescale-for-high-order-cfd-simulation/ AE-705 Introduction to Flight Lecture 07 Capsule-04
Developed to fly faster Aim: Maintain laminar flow over larger chord AE-705 Introduction to Flight Lecture 07 Capsule-04
Developed to fly faster Aim: Maintain laminar flow over larger chord AE-705 Introduction to Flight Lecture 07 Capsule-04
WHY LAMINAR AIRFOILS? Turbulent flow on airfoil more stable?? P-51 Mustang Simple Answer: Skin friction drag compared to turbulent flow AE-705 Introduction to Flight Lecture 07 Capsule-04
WHY LAMINAR AIRFOILS? Turbulent flow on airfoil more stable?? P-51 Mustang Simple Answer: Skin friction drag compared to turbulent flow https://en.wikipedia.org/wiki/North_American_P-51_Mustang AE-705 Introduction to Flight Lecture 07 Capsule-04
Fly at low speed…. LOW REYNOLDS NUMBER AIRFOIL AE-705 Introduction to Flight Lecture 07 Capsule-04
LRN AIRFOILS Reynolds number inertial effects vs viscous (fluid stickiness) effects Grumman HU-16B Albatross Drag or stream Limiting and wise resistance controlling the maximum lift Chord Reynolds Number = Vc/ ν AE-705 Introduction to Flight Lecture 07 Capsule-04
LRN AIRFOILS Reynolds number inertial effects vs Gossamer Albatross viscous (fluid stickiness) effects Drag or stream Limiting and wise resistance controlling the maximum lift Source: http://www.humanpoweredflying.propdesigner.co.uk/html/the_gossamers.html AE-705 Introduction to Flight Lecture 07 Capsule-04
LRN AIRFOILS Reynolds number inertial effects vs viscous (fluid stickiness) effects Grumman HU-16B Albatross Drag or stream Limiting and wise resistance controlling the maximum lift Source: https://media.defense.gov/2005/Dec/26/2000574422/670/394/0/050322-F-1234P-028.JPG AE-705 Introduction to Flight Lecture 07 Capsule-04
Faster than sound!!! SUPERSONIC AIRFOIL AE-705 Introduction to Flight Lecture 07 Capsule-04
Notice here Source: https://www.rt.com/usa/330524-sonic-boom-new-jersey/ AE-705 Introduction to Flight Lecture 07 Capsule-04
Engines (powerful) easy v( ) High speeds difficult for flow to remain attached Do you notice something? Sharp LE AE-705 Introduction to Flight Lecture 07 Capsule-04
Have you ever wondered that you could be flying on a plane producing shock waves?? Now what does that mean?? Video Courtesy: Russell Croman (https://www.youtube.com/watch?v=HekbC6Pl4_Y) AE-705 Introduction to Flight Lecture 07 Capsule-04
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