Flap mechanism

1. VISVESVARAYA TECHNOLOGICAL UNIVERSITY
BELAGAVI
Technical Seminar Presentation On
AIR PLANE FLAP MECHANISM
Presented by
Abhishek S Turamandi 4BB13ME003
Under the Guidance of
Mr. DEEPU C.N BE.M. TECH
ASSISTANT PROFESSOR
DEPARTMENT OF MECHANICAL ENGINEERING
Bahubali College of Engineering
Shravanabelagola-573 135
2016-17
4/4/2017
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2.  CONTENTS
 Introduction
 History
 Airplanes
 Types of flaps
 Equation of motion
 Principle of operation
 Conclusion
 References
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3.  INTRODUCTION
Flaps are a type of
high-lift device used to
increase the lift of an
aircraft wing at a given
airspeed.
Flaps are usually
mounted on the wing
trailing edges of a
fixed-wing aircraft.
Flaps are used to
lower the minimum
speed at which the
aircraft can be safely
flown, and to increase
the angle of descent
for landing.
Flaps also cause an
increase in drag, so
they are retracted
when not needed.
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4.  HISTORY
 The Greek legend of Icarus and Daedalus, and the Vimana in
ancient Indian epics.
 Around 400 BC in Greece, Archytas was reputed to have designed
and built the first artificial, a bird-shaped model propelled by a jet
of what was probably steam.
 Leonardo da Vinci researched the wing design of birds and
designed a man-powered aircraft in his Codex on the Flight of
Birds.
 The Wright brothers invented and flew the first airplane in 1903,
recognized as "the first sustained and controlled heavier-than-air
powered flight".
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5.  AIR PLANES
 An airplane is a powered, fixed-wing aircraft that is propelled
forward by thrust from a jet engine or propeller.
 Characteristic
 Airframe
The structural parts of a fixed-wing aircraft are called the
airframe.
 Wings
The wings of a fixed-wing aircraft are static planes extending
either side of the aircraft.
When the aircraft travels forwards, air flows over the wings which
are shaped to create lift. This shape is called an airfoil and is shaped
like a bird's wing.
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6.  Contd…
Wings vs. bodies
Wings
I. A flying wing is a tailless aircraft which
has no definite fuselage.
II. In contrast to a flying wing…wing are
needed to produce lift.
III. Wing with minimal or no conventional
fuselage.
IV. Flying wing seeks to maximize cruise
efficiency at subsonic speeds by
eliminating non-lifting surfaces
Bodies
I. Blended wing body aircraft have a
flattened and airfoil shaped body,
which produces most of the lift to keep
itself a loft, and distinct and separate
wing structures.
II. A lifting body is a configuration in
which the body itself produces lift.
III. Lifting body can be thought of as a
fuselage with little or no conventional
wing.
IV. lifting bodies generally minimize the
drag and structure of a wing for
subsonic, supersonic, and hypersonic
flight.
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7.  TYPES OF FLAPS
 Plane flap
The rear portion of airfoil rotates downwards on a simple hinge
mounted at the front of the flap. the plain flap is normally only used
where simplicity is required.
Figure: Plane flap
 Split flap
At full deflection, a split flaps acts much like a spoiler, adding
significantly to drag coefficient.
Figure: Split flap
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8.  Slotted flap
Any flap that allows air to pass between the wing and the flap is
considered a slotted flap.
Figure: Slotted flap
Figure: Slotted flap
 Fowler flap
The flap may form part of the upper surface of the wing, like a
plain flap, or it may not, like a split flap, but it must slide rearward
before lowering. It may provide some slot effect, but this is not a
defining feature of the type.
Figure: Fowler flap
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9.  Junkers flap
A slotted plain flap where the flap is fixed below the trailing edge
of the wing, rotating about its forward edge, and usually forming the
"inboard" hinged section of the Junkers "double-wing" style of wing
trailing edge.
Figure: Junkers flap
 Gouge flap
A type of split flap that slides backward along curved tracks
that force the trailing edge downward, increasing chord and
camber without affecting trim or requiring any additional
mechanisms.
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10. Contd…
Figure: Gouge flap
 Fairey-Youngman flap
Drops down before sliding aft and then rotating up or down.
When in the extended position, it could be angled up so that the
aircraft could be dived vertically without needing excessive trim
changes.
Figure: Fairey-Youngmanflap
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11.  Zap Flap
When the flap's leading edge moves aft along the track, the triangle
formed by the track, the shaft and the surface of the flap gets narrower
and deeper, forcing the flap down.
Figure: Jap flap
 Krueger flap
A hinged flap which folds out from under the wing's leading edge
while not forming a part of the leading edge of the wing when
retracted.
Figure: Kruger flap
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12.  Gurney flap
A small fixed perpendicular tab of between 1 and 2% of the wing
chord, mounted on the high-pressure side of the trailing edge of an
airfoil.
Figure: Gurney flap
 Leading edge flap
The entire leading edge of the wing rotates downward, effectively
increasing camber and also slightly reducing chord.
Figure: Leading edge flap 4/4/2017
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13. Blown flap
A type of Boundary Layer Control System, blown flaps pass engine-
generated air or exhaust over the flaps to increase lift beyond that
attainable with mechanical flaps.
Figure: Blown flap
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14.  EQUATION OF MOTION
 The term flight mechanics refers to the analysis of airplane motion
using Newton’s laws.
 Newton’s laws are valid when written relative to an inertial
reference frame.
 For airplane motion, the earth is an approximate inertial reference
frame, and this model is called the flat earth model.
 A general derivation of the equations of motion involves the use of
a material system involving both solid and fluid particles.
 The end result is a set of equations giving the motion of the solid
part of the airplane subject to aerodynamic, propulsive and
gravitational forces.
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15.  The correct equations for the forces are assumed to be known.
 The airplane is assumed to have a right-left plane of symmetry with
the forces acting at the center of gravity.
 The forces acting on an airplane in fight are due to distributed
surface forces and body forces.
Figure: Distributed v/s concentrated forces
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16.  PRINCIPLES OF OPERATION
 The general airplane lift equation demonstrates these relationships
where:
 L is the amount of Lift produced, is the air density,
 V is the true airspeed of the airplane or the Velocity of the airplane,
relative to the air
 S is the wing area
 CL is the lift coefficient
Figure 5.1: Flap position 4/4/2017
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17.  Drag coefficient
In fluid dynamics, the drag coefficient is a dimensionless quantity
that is used to quantify the drag or resistance of an object in a fluid
environment, such as air or water.
 Lift coefficient
The lift coefficient (CL) is a dimensionless quantity that relates the
lift generated by a lifting body to the fluid density around the body.
 Bernoulli’s Principle
Newton's 2nd law. “If a small volume of fluid is flowing
horizontally from a region of high pressure to a region of low pressure,
then there is more pressure behind than in front”.
 Newton’s second law
The second law states that “the rate of change of momentum
of a body, is directly proportional to the force applied and this
change in momentum takes place in the direction of the applied
force”.
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18.  Flaps Operational Functions
 Flaps during takeoff
Depending on the aircraft type, flaps may be partially extended for
takeoff.
Flaps trade runway distance for climb rate using flaps reduces ground roll
and the climb rate.
The Cessna 172S Pilot Operating Handbook generally recommends 10°
of flaps on takeoff, especially when the ground is rough or soft.
 Flaps during landing
Flaps may be fully extended for landing to give the aircraft a lower stall
speed, allows the aircraft to land in a shorter distance.
 Maneuvering flaps
Some gliders not only use flaps when landing but also in flight to
optimize the camber of the wing for the chosen speed.
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19. Contd…
At higher speeds a negative flap setting is used to reduce the nose-
down pitching moment.
 Flap tracks
Extending flaps often run guide tracks ,track fairings are designed to
act as anti-shock bodies.
 Thrust gates
Thrust gates, or gaps, in the trailing edge flaps, may be required to
minimize interference between the engine flow and deployed flaps.
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20.  CONCLUSION
 The flap mechanism of different types are proved to be
advantageous for giving lift to the airplane while takeoff, and for
proper landing of the air plane.
 Different types of flaps are because depending on the air craft type
flaps are used.
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21.  REFERENCES
Book
[1]“Bernoulli’s Theorem”, Fluid Mechanics,Dr. R.K.BANSAL, Laxmi publication’s, First edition 2005,
Page number 227.
Journal
[2]“Airplane Flap Mechanism”, G V School Publication International Journal of ICT-aided Architecture
and civil Engineering, volume Number 2,(2016).
Website
[3] “Air Plane”
[Retrived on: 10-11-2016,https://en.wikipedia.org/wiki/Airplane,https://www.grc.nasa.gov/WWW/k-
12/airplane/flap.html]
[4] “Flap mechanism”
[Retrived on:10-11-2016, https://en.wikipedia.org/wiki/Flap_(aeronautics)]
[5] “Equation of Motion”
[Retrived on: 10-11-2016, hull_airplane_flight_mechanics.pdf]
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