The document provides an overview of the principles of flight for airplanes. It explains that airplanes fly due to Bernoulli's principle, which states that as the speed of a fluid increases, its pressure decreases. The shape of airplane wings, being curved on top and flat on bottom, causes the air to travel faster over the top of the wing, thus decreasing the pressure and generating lift. Airplanes move forward either through propellers, which also use Bernoulli's principle to generate thrust, or jet engines, which produce thrust through combustion and Newton's third law of motion. Key concepts like lift, drag and momentum are also discussed in the context of airplane flight.

1. WELCOME!!WELCOME!!

2. THE PRINCIPALS OFTHE PRINCIPALS OF
FLIGHT OFFLIGHT OF
AN AEROPLANEAN AEROPLANE
PRESENTATION BYPRESENTATION BY
MR. NIKHIL D. PISEMR. NIKHIL D. PISE

3. • Aeroplanes fly because of a physicalAeroplanes fly because of a physical
principal discovered by a Dutch scientistprincipal discovered by a Dutch scientist
named Daniel Bernoulli (1700 - 1782).named Daniel Bernoulli (1700 - 1782).
• BERNOULLI’s PRINCIPALBERNOULLI’s PRINCIPAL::
This principal says that as the speedThis principal says that as the speed
(velocity V) of a fluid increases, its(velocity V) of a fluid increases, its
pressure (P) decreases. Since the flow ofpressure (P) decreases. Since the flow of
air over an airplane wing acts like a fluid,air over an airplane wing acts like a fluid,
the principal applies. the principal applies.

4. • The Shape of Airplane Wings:The Shape of Airplane Wings:
Airplane wings, like birds' wings, areAirplane wings, like birds' wings, are
curved on top and flat on the bottom.Therecurved on top and flat on the bottom.There
is an old saying that you might haveis an old saying that you might have
heard: "The shortest distance betweenheard: "The shortest distance between
two point is a straight line." If the bottom oftwo point is a straight line." If the bottom of
the wing is flat (straight) while the top ofthe wing is flat (straight) while the top of
the wing curves up and then back down,the wing curves up and then back down,
then the length of the line on the top of thethen the length of the line on the top of the
wing is longer than the line on the bottom.wing is longer than the line on the bottom.

6. A Tale of Two MoleculesA Tale of Two Molecules
• Let us take a look at two air molecules, one traveling onLet us take a look at two air molecules, one traveling on
the top side of the wing (Mtop), and the other travelingthe top side of the wing (Mtop), and the other traveling
on the bottom side of the wing (Mbottom). There areon the bottom side of the wing (Mbottom). There are
other air molecules all around our two molecules, so theyother air molecules all around our two molecules, so they
must move along the wing.must move along the wing.
• They will start at the tip of the wing, and meet at the backThey will start at the tip of the wing, and meet at the back
(or trailing edge) of the wing. They must both get to the(or trailing edge) of the wing. They must both get to the
back of the wing at the same time. Since the top surfaceback of the wing at the same time. Since the top surface
of the wing is longer than the bottom surface because ofof the wing is longer than the bottom surface because of
the curve, the molecule on the top must travel faster thanthe curve, the molecule on the top must travel faster than
the molecule on the bottom.the molecule on the bottom.

7. • According to Bernoulli's Principal, as theAccording to Bernoulli's Principal, as the
molecule on top goes faster (velocity increases)molecule on top goes faster (velocity increases)
then its pressure decreases. Therefore, thethen its pressure decreases. Therefore, the
pressure on the bottom of the wing is greaterpressure on the bottom of the wing is greater
than the pressure on the top of the wing. Thisthan the pressure on the top of the wing. This
difference in pressure causes the wing to movedifference in pressure causes the wing to move
up. This is called the Bernoulli Effect. Withup. This is called the Bernoulli Effect. With
airplanes, this upward movement is called Lift.airplanes, this upward movement is called Lift.
The faster the airplane goes through the air,The faster the airplane goes through the air,
the greater is the lift generated by the air flowingthe greater is the lift generated by the air flowing
over the wings.over the wings.

8. What Makes the Airplane MoveWhat Makes the Airplane Move
Forward?Forward?
There are two basic types of airplanes –There are two basic types of airplanes –
1.Propeller driven planes and 2.Jet planes.1.Propeller driven planes and 2.Jet planes.

9. • Propeller Driven PlanesPropeller Driven Planes - Propeller- Propeller
driven airplanes use a propeller that isdriven airplanes use a propeller that is
turned by some type of engine. Propellersturned by some type of engine. Propellers
also depend on Bernoulli's Principal toalso depend on Bernoulli's Principal to
function. They are shaped just like thefunction. They are shaped just like the
wings, and also generate lift, except thatwings, and also generate lift, except that
the lift is forward instead of up and isthe lift is forward instead of up and is
called thrust. Each propeller is made up ofcalled thrust. Each propeller is made up of
two or more blades.two or more blades.

10. • Jet PlanesJet Planes - Jet planes do not have- Jet planes do not have
propellers. Instead, they have jet enginespropellers. Instead, they have jet engines
that move the airplane forward throughthat move the airplane forward through
another physical principal discovered by Siranother physical principal discovered by Sir
Isaac Newton (1642 - 1727). This is Newton'sIsaac Newton (1642 - 1727). This is Newton's
Third Law of Motion - "For every action thereThird Law of Motion - "For every action there
is an equal and opposite reaction."is an equal and opposite reaction."

11. • You can think of a jet engine as a tube inYou can think of a jet engine as a tube in
which a liquid fuel (like the fuel diesel truckwhich a liquid fuel (like the fuel diesel truck
use) is burned at high pressure with airuse) is burned at high pressure with air
from a compresser. The resulting heatfrom a compresser. The resulting heat
forces the gases out of the back of theforces the gases out of the back of the
tube at high speed. In accordance withtube at high speed. In accordance with
Newton's Law, an equal force is applied inNewton's Law, an equal force is applied in
the forward direction, moving the enginethe forward direction, moving the engine
(and the plane it is attached to) forward .(and the plane it is attached to) forward .

12. • LANGLEY'S LAWLANGLEY'S LAW -- The law enunciated-- The law enunciated
by Langley is, that the greater the speedby Langley is, that the greater the speed
the less the power required to propel it.the less the power required to propel it.
Water as a propelling medium has overWater as a propelling medium has over
seven hundred times more force than air.seven hundred times more force than air.
A vessel having, for instance, twentyA vessel having, for instance, twenty
horse power, and a speed of ten miles perhorse power, and a speed of ten miles per
hour, would require four times that powerhour, would require four times that power
to drive it through the water at double theto drive it through the water at double the
speed. The power is as the square of thespeed. The power is as the square of the
speed.speed.

13. • THEORIES AND FACTS ABOUT FLYINGTHEORIES AND FACTS ABOUT FLYING
• THE "SCIENCE" OF AVIATIONTHE "SCIENCE" OF AVIATION.. -- It may be-- It may be
doubted whether there is such a thing as adoubted whether there is such a thing as a
"science of aviation." Since Langley, on May 6,"science of aviation." Since Langley, on May 6,
1896, flew a motor-propelled tandem monoplane1896, flew a motor-propelled tandem monoplane
for a minute and an half, without a pilot, and thefor a minute and an half, without a pilot, and the
Wright Brothers in 1903 succeeded in flying a bi-Wright Brothers in 1903 succeeded in flying a bi-
plane with a pilot aboard, the universal opinionplane with a pilot aboard, the universal opinion
has been, that flying machines, to be successful,has been, that flying machines, to be successful,
must follow the structural form of birds, and thatmust follow the structural form of birds, and that
shape has everything to do with flying.shape has everything to do with flying.

14. • MOMENTUM A FACTORMOMENTUM A FACTOR.. -- Each had-- Each had
transferred to it a motion. The initial speedtransferred to it a motion. The initial speed
was the same, and the power set up equalwas the same, and the power set up equal
in the two. Why this difference, the answerin the two. Why this difference, the answer
is, that it is in itself. It was the mass oris, that it is in itself. It was the mass or
density which accounted for thedensity which accounted for the
difference. It was mass multiplied bydifference. It was mass multiplied by
speed which gave it the power, called, inspeed which gave it the power, called, in
this case, momentum.this case, momentum.

15. • We have two balls the same diameter,We have two balls the same diameter,
one of iron weighing a half pound, and theone of iron weighing a half pound, and the
other of cotton weighing a half ounce. Theother of cotton weighing a half ounce. The
weight of one is, therefore, sixteen timesweight of one is, therefore, sixteen times
greater than the other.greater than the other.
Suppose these two balls are thrown withSuppose these two balls are thrown with
the expenditure of the same power. Whatthe expenditure of the same power. What
will be the result! The iron ball will gowill be the result! The iron ball will go
much farther, or, if projected against a wallmuch farther, or, if projected against a wall
will strike a harder blow than the cottonwill strike a harder blow than the cotton
ball.ball.

16. • RESISTANCERESISTANCE. -- Now, in the movement. -- Now, in the movement
of any body through space, it meets withof any body through space, it meets with
an enemy at every step, and that is airan enemy at every step, and that is air
resistance. This is much more effectiveresistance. This is much more effective
against the cotton than the iron ball: or, itagainst the cotton than the iron ball: or, it
might be expressed in another way: Themight be expressed in another way: The
momentum, or the power, residing in themomentum, or the power, residing in the
metal ball, is so much greater than thatmetal ball, is so much greater than that
within the cotton ball that it travels farther,within the cotton ball that it travels farther,
or strikes a more effective blow on impactor strikes a more effective blow on impact
with the wall.with the wall.

17. • HOW RESISTANCE AFFECTS THE SHAPE.HOW RESISTANCE AFFECTS THE SHAPE.
-- It is because of this counterforce, resistance,-- It is because of this counterforce, resistance,
that shape becomes important in a flying object.that shape becomes important in a flying object.
The metal ball may be flattened out into a thinThe metal ball may be flattened out into a thin
disk, and now, when the same force is applied, todisk, and now, when the same force is applied, to
project it forwardly, it will go as much farther asproject it forwardly, it will go as much farther as
the difference in the air impact against the twothe difference in the air impact against the two
forms.forms.

18. • THE LIFTING SURFACES OFTHE LIFTING SURFACES OF
AEROPLANESAEROPLANES
This subject includes the form, shape andThis subject includes the form, shape and
angle of planes, used in flight. It is theangle of planes, used in flight. It is the
direction in which most of the energy hasdirection in which most of the energy has
been expended in developing machines,been expended in developing machines,
and the true form is still involved in doubtand the true form is still involved in doubt
and uncertainty.and uncertainty.

19. • LIFT AND DRIFTLIFT AND DRIFT. -- The terms should be. -- The terms should be
explained, in view of the frequent allusion whichexplained, in view of the frequent allusion which
will be made to the terms hereinafter. Lift is thewill be made to the terms hereinafter. Lift is the
word employed to indicate the amount which aword employed to indicate the amount which a
plane surface will support while in flight. Drift isplane surface will support while in flight. Drift is
the term used to indicate the resistance which isthe term used to indicate the resistance which is
offered to a plane moving forwardly against theoffered to a plane moving forwardly against the
atmosphere. the plane A is assumed to beatmosphere. the plane A is assumed to be
moving forwardly in the direction of the arrow B.moving forwardly in the direction of the arrow B.
This indicates the resistance. The vertical arrowThis indicates the resistance. The vertical arrow
C shows the direction of lift, which is the weightC shows the direction of lift, which is the weight
held up by the plane.held up by the plane.

20. • NARROW PLATES MOST EFFECTIVENARROW PLATES MOST EFFECTIVE..
-- It was learned, in the early stages of the-- It was learned, in the early stages of the
development by practical experiments,development by practical experiments,
that a narrow plane, fore and aft, producesthat a narrow plane, fore and aft, produces
a greater lift than a wide one, so that,a greater lift than a wide one, so that,
assuming the plane has 100 square feet ofassuming the plane has 100 square feet of
sustaining surface, it is far better to makesustaining surface, it is far better to make
the shape five feet by twenty than ten bythe shape five feet by twenty than ten by
ten.ten.

21. • However, it must be observed, that toHowever, it must be observed, that to
use the narrow blade effectively, it mustuse the narrow blade effectively, it must
be projected through the air with the longbe projected through the air with the long
margin forwardlymargin forwardly
• Its sustaining power per square foot ofIts sustaining power per square foot of
surface is much less if forced through thesurface is much less if forced through the
air lengthwise.air lengthwise.

22. THANK YOU !!!!THANK YOU !!!!