Philippine State College of Aeronautics
Institute of Engineering and Technology
[Course Code and Title]
[Module #: Module Title]
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POINTS TO PONDER
WHY DO WE USE FLAPS DURING TAKEOFF?
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TRAILING EDGE HLD
Aka flaps
1. Plain Flaps – no gap, whole portion of the trailing edge
MODULE OUTLINE
1.
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Red – normal chord (lower camber)
Blue – chord with deflected flaps. (higher difference in curvature,
higher camber, higher CLmax)
HIGH LIFT DEVICES
To improve the generation of lift
E.g. flaps
o
Leading edge or trailing edge (more common)
How do these improve the generation of lift?
o
Modifying wing characteristics, CAMBER. Binabago
nya yung difference of curvater na meron ka sa upper
and lower surfaces to create greater lift.
o
At a particular angle of attack, CLmax increases as the
thickness of your airfoil increases.
o
higher camber, higher CLmax at a low angle of
attack
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you don’t need to fly at a high speed
(beneficial during landing and takeoff,
hence the use of flaps)
2.
Split Flaps – almost half of the TE only. Deflects only the
lower surface, still no gap.
3.
Slotted Flaps – may gap (slot) between the wing and itself.
Adds more lift. Yung airflow na dumadaan sa gap na magpo-flow sa
upper surface ng flaps would create new pressure difference, hence
the production of additional lift.
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4.
Fowler Flaps – gives more surface area na tinatamaan ng
airflow (aside pa sa change in camber). Lift is directly
proportional to surface area.
5.
Double Slotted Fowler – 2 gaps (addtl sources of lift) +
camber + surface area
LEADING EDGE HLD
Aka slats
They generate slots (redirection of flow for better pressure
difference between the upper and lower surfaces of your wing)
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Level flight condition: L = W
o
This is where we get the idea of the stalling speed.
o
For the topic of stalling, we set level flight
STALLING SPEED
It is a function of CLmax.
Lowest possible velocity that an aircraft can fly.
Critical AOA – highest AOA prior to stalling.
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Slat – changes curvature of LE using hydraulic
Krueger Flap – for commercial planes, counterpart of fowler
but in LE,
Fixed Slat – immovable, increase camber, re
GROUND EFFECT
May certain height where this is effective.
Generation of greater lift during takeoff and landing
“Swirling” / wing tip vortices – nangyayari kasi yung opposing
directions ng air na gusto tumaas at bumaba ay naggme-meet
halfway sa leaking points.
Yung mga swirling ay may direction component na pababa.
Newt’s 3rd law of motion, yung mga forces na yun ay nag-e-exert
ng force pabalik (pataas), increasing lift, hence the ground effect.
Mababa ang induced drag kasi yung ground, obstruction siya sa
production ng wing tip vortices and downwash. Kasi di nabubuo
ng vortices yung dapat na circular movement nya.
Is this beneficial?
o
NO. KASI IT COULD GIVE U A SUDDEN LOSS OF
LIFT KAPAG MAS TUMAAS KA PA FROM THE
HEIGHT OF EFFECTIVE GROUND EFFECT.
o
FOR EXAMPLE, 100 LBS OF LIFT ANG NAPOPRODUCE NG GROUND EFFECT AND ANG
PRESCRIBED LIFT MO LANG AY 90 LBS. PAG
NAWALA KA SA GROUND EFFECT, BABABA
DRASTICALLY ANG LIFT MO  BABABA KA ULIT ++
MAY CHANCE NA NAG-LIFT KA NA DUE TO
GROUND EFFECT ONLY PERO DI MO NA-ATTAIN
ANG LIFT OFF SPEED MO. IN THIS CASE, YOU
WOULD CONSUME LONGER TAKEOFF ROLL
(PRONE TO OVERSHOOTING).
AERODYNAMICS OF CYLINDERS AND SPHERES
[Course Code] | Module #: Module Title
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Philippine State College of Aeronautics
Institute of Engineering and Technology
[Course Code and Title]
[Module #: Module Title]
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MAGNUS EFFECT
An observable phenomenon commonly associated with the
spinning object moving through a fluid.
KUTTA-JOUKOWSKI THEOREM
MARTIN KUTTA & NIKOLAI JOUKOWSKI
Rotating body / shape (cylinder and sphere) to produce lift
o
CIRCULATION ADDED TO A FLOW  LIFT
If fixed cylinder lang, walang lift kasi same lang ang pressure
distribution sa upper and lower surface
KAPAG UMIIKOT NA YUNG CYLINDER, MAGKAKAROON NG
PRESSURE DIFFERENTIAL  LIFT due to the downward
momentum of the flow at the upper surface (causes lift, 3rd law of
motion)
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