Aircraft Layout Choices Prof. Rajkumar S. Pant Aerospace - - PowerPoint PPT Presentation

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Aircraft Layout Choices Prof. Rajkumar S. Pant Aerospace - - PowerPoint PPT Presentation

Feb 09, 2024 114 likes •334 views

Aircraft Layout Choices Prof. Rajkumar S. Pant Aerospace Engineering Department IIT Bombay Many letters of English Alphabet !!! TAIL PLANE LAYOUT AE-332M / 714 Aircraft Design Capsule-2 Requirements from the Tailplane Horizontal Tail

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SLIDE 1

Aircraft Layout Choices

  • Prof. Rajkumar S. Pant

Aerospace Engineering Department IIT Bombay

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SLIDE 2

AE-332M / 714 Aircraft Design Capsule-2

TAIL PLANE LAYOUT

Many letters of English Alphabet !!!

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SLIDE 3

Requirements from the Tailplane

 Horizontal Tail

  • Trim
  • Wing pitching moment
  • Stability
  • Pitching motion
  • Control
  • Nosewheel liftoff
  • Low speed flight with flaps

down

  • Transonic maneuvering

 Vertical Tail

  • Trim
  • Engine failure
  • Single engine asymmetry
  • Stability
  • Yawing motion
  • Dutch roll damping
  • Control
  • Engine out flight at low speeds
  • Maximum roll rate
  • Spin recovery
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SLIDE 4

Aft Tailplane Configuration Options

Conventional tail is seen in nearly 70% a/c

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SLIDE 5

T-Tail

 Smaller vertical tail due to end-

plate effect

 Clear of wing and prop wash  Ease in mounting of rear engines  Heavier  Deep stall

Source: Wikipedia

http://en.wikipedia.org/wiki/Deep_stall#Deep_stall

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SLIDE 6

AE-332M / 714 Aircraft Design Capsule-2

T-Tail v/s Conventional Tail

 Advantages (of T-Tail)

  • Looks Faster
  • Lesser FOD from Eng. & LG
  • Allow rear-mounted engines

 Disadvantages

  • Pilots don’t like it
  • When pilots add power on a

single-engined aircraft, they get additional control authority

  • Bad for maintenance
  • Alaska MD-83's accident
  • http://www.ntsb.gov/publictn

/2002/AAR0201.htm

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SLIDE 7

Some aircraft with T-Tail

Piper Tomahawk Canadair CRJ F101-Voodoo ETA glider

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SLIDE 8

Cruciform Tail

Compromise between

Conventional & T-Tail

  • JS-31, DHC-6, Falcon 20, ATR-42
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SLIDE 9

Twin Tail

 Lower overall height  Avoid fuselage wake on rudder  spin resistance  higher structural weight

Many examples

AN-225, F-15, MiG-25

http://en.wikipedia.org/wiki/File:F-15,_71st_Fighter_Squadron,_in_flight.JPG

http://en.wikipedia.org/wiki/File:Buran_On_Antonov225.jpg http://www.atlasaerospace.net/image/f_pilotag8.jpg

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SLIDE 10

H and Triple Tail

Triple Tail

lower VT to fit into hangers

 H Tail

  • undisturbed airflow on VT at

high AOA

  • VT in propwash to enhance

engine-out controllability

  • Smaller HT due to endplate

effect

Lockheed Constellation P-38

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SLIDE 11

Butterfly or V- Tail

 Reduction of one tail surface

  • Lower interference drag
  • Lower weight
  • Higher Complexity
  • Mixing unit required

Beechcraft Bonanza F-117A

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SLIDE 12

AE-332M / 714 Aircraft Design Capsule-2

Other Aircraft with V Tail

Cirrus Vision SF 50 Eclipse 400 RQ4/MQ4 Global Hawk Fouga CM 120 Magister

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SLIDE 13

AE-332M / 714 Aircraft Design Capsule-2

WING GEOMETRY

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SLIDE 14

AE-332M / 714 Aircraft Design Capsule-2

Wing Geometry

C0 = root chord CT = tip chord b = wing span s = wing semi-span S = wing ref. area t = thickness c = chord α = angle of attack Λ = Taper Ratio = CT/C0 AR = Aspect Ratio = b2/S t/c = Thickness Ratio

Source: Fielding, J. P., Introduction to Aircraft Design

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SLIDE 15

AE-332M / 714 Aircraft Design Capsule-2

0 - 35 subs. 35 - 70 supers.

Wwing

CD0 CDi Leading-edge sweep angle 4 - 14 subs. 2 - 5 supers.

Wwing

CDi Taper Ratio 7 – 9 subs. 2 – 4 supers.

Wwing

CD ind

K

Aspect Ratio 5 - 18 % subs. 3 - 7 % supers.

Wwing

CL max CD Airfoil Thickness ratio 0 – 6 %

Wwing~ const

CL CD Airfoil Camber

Range of Values

Effecting on wing weight

Trends

Effecting on wing polar and CL

Geometrical Parameter

CL α CL α CL CD Cy CD CL CD CL

Effect of Wing Geometry: Aerodynamics and Weight

  • subs. = subsonic flight
  • supers. = supersonic flight
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SLIDE 16

Reference wing planform = Trapezoidal

  • Aspect Ratio (b2/s or b/c for rectangular wing)
  • Increase in AR

 Reduces induced drag  Reduces stalling AOA  Increases subsonic (L/D)max  Increases wing weight

  • Sweep
  • Taper Ratio
  • Twist
  • Incidence
  • Dihedral

Wing Layout Parameters

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SLIDE 17

 λ = tip chord / root chord

  • (root chord / tip chord in USA)

 λ = 1 (Rectangular wing)

Heavy Ease in construction

 Low λ

Lower wing root BM  lighter wing tip stalls before root  poor stalling behavior

 Compromise Value: usually 0.4 to 0.6

Taper ratio

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SLIDE 18

 No clearcut indication from Accident/Emergency stats  > Airlines prefer smallest number of engines  Often dictated by availability  2 engines for extended over-water flights

  • ETOPS clearance

Number of Engines

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SLIDE 19

AE-332M / 714 Aircraft Design Capsule-2 ETP 1 E.ALT 2

  • D. AL

T Departure Destination ETP2 (CP) EEP EEP : ETOPS Entry Point ETP : Equitime Point E.ALT : En-route Alternate Airport D.ALT: Destination Alternate ETOPS Segment 60 minute circles Maximum diversion time circles Unauthorised area

Area of Operation

E.ALT 1

Illustration of ETOPS

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SLIDE 20

AE-332M / 714 Aircraft Design Capsule-2

MANY CONFIGURATIONS AND LAYOUT POSSIBILITIES EXIST

Choose your pick !