A Review on Airplane Parts and Aerodynamics

Review On :-1) Forces acting on the Aircraft (Four

Forces)

2) Bernoulli’s Principle

3) Airplane Parts

4) Debate whether Airplane can stay

stationary in air?

Forces :-• Force – a push or a pull acting

on a body.• As a plane flies it is in the center

of 4 forces.– Weight, lift, drag and thrust

• Two natural forces being exerted on plane– Weight and drag

• A pilot needs to overcome weight and drag to achieve flight

• Two forces a pilot needs to create to overcome weight and drag– Lift and thrust

• Lift & thrust are required to keep the airplane in the air

Lift

Weight

Drag Thrust

Lift:-• Lift is the upward force on a plane

– Various parts of a plane help to achieve lift• But most of the lift is created

by the wings• The magnitude of lift depends on

the shape, size and velocity– For example, the faster the

plane goes the greater the lift• The lift that is produced by the

wings must be greater than the weight of plane to leave the ground.

Weight:-• Weight is defined as the

downward force of gravity– Force is always directed

toward the center of the earth• Weight is distributed throughout

the plane• The magnitude of the weight

depends on the mass of the plane plus the fuel, the people and baggage

• A pilot must overcome weight by lift to get the plane in the air

Thrust:-• Thrust is defined as the forward push

that gets the plane into the air– Thrust is artificially created and used to

overcome drag and to sustain lift• This force is provided by the propeller or jet

engine

• Thrust is also used to accelerate and gain altitude

Drag:-• Drag is a resistance force

created by the plane’s movement through the air– The force of the air pushes

against the plane, therefore slowing the plane down

• The magnitude of drag depends on the shape, air quality and velocity

• Drag increases as air speed increases– A pilot must overcome drag with

thrust to gain speed

Engines (either jet or propeller) typically provide the thrust for aircraft. When you fly a paper airplane, you

generate the thrust.

Important Concepts Air• Principal concept in aerodynamics is the idea that

air is a fluid– Air has mass, therefore it has weight

• Because it has weight, it exerts pressure

– Air flows and behaves in a similar manner to other liquids

– Air has molecules which are constantly moving

• Lift can exist only in the presence of a moving fluid– Faster moving fluids exert less force on surfaces they

are flowing along

As an airplane moves forward, the airflow As an airplane moves forward, the airflow splits up into two separate flowssplits up into two separate flows

Before We Begin…

Bernoulli’s Principle Defined

• Bernoulli’s Principle states that when the speed of a moving fluid increases, the pressure decreases and when the speed of a moving fluid decreases, the pressure increases.

Bernoulli’s Principle• Air flowing around the wing experiences a change in speed and each

change in speed is accompanied by a change in pressure– Airflow going under the wing encounters a sloping surface

• Slows airflow down and slow moving air maintains a higher pressure on the bottom surface

– Airflow going over the wing encounters the up/down sloping• Slows the airflow down, then it speeds it up; with the faster moving air a lower

pressure develops on the below surface – Air going over must travel farther, so its average speed is greater

than the speed of the air below• Result: A reduction in sidewise pressure whichoccurs at the top, exerting a lifting force on theentire wing

• Pressure imbalance produces an overall upward force

Bernoulli’s Principle Diagram

Bernoulli’s Principle: Air moving over the wing moves faster than the air below. Faster-moving air above exerts less pressure on the wing than the slower-moving air below. The result is an upward push on the wing--lift!

Conservation of Energy(Bernoulli’ s Principle)

Bernoulli principle derived from the Law of Conservation of Energy• A fluid under pressure has potential energy.

– Energy can be stored in pressurized air– The higher the pressure the greater the potential energy

• Moving fluids have both potential energy and kinetic energy. – Total energy must remain constant,so its potential energy decreases, and which means its pressure decreases as well– When the air’s speed andmotional energy increase, the pressure and pressure energy must decrease to compensate

• Speed increases over the wing because the airflow converts some of its pressure energy into kinetic energy

Bernoulli’s Theory in Action

Air speeds up in the constricted space between the car & truck creating a low-pressure area. Higher pressure on the other outside pushes

them together.

The distance traveled is the same. Equal distances in equal times means

the air is traveling at same speed. There’s no net force=no lift.

The curved shape is a longer distance so the air is traveling faster. Equal

distances traveled in equal times. No net force=no lift.

The air on top is traveling faster. It exerts less force. When 2 forces are combined they do not cancel

each other out. Therefore there is some net force upward.

Shape of the Wing

Bernoulli’s Principle

Factors Which Affect the Amount of Lift Created• Speed

– The faster the wing moves through the air the more air is forced over and under

• So a plane must maintain ample velocity to keep the upward lifting force– If it slows down too much—lift decreases—plane descend

• Density of air– The denser the air the more lift (colder air is more dense; air density

changes with altitude)• Planes climb better in winter.

• Shape of wing– Asymmetrical

• Angle of attack (its tilt relative to the wind)– Downside: increases drag

Various Parts of Aircraft

Airplane Parts

• Fuselage• Wings• Ailerons• Flaps• Rudder• Horizontal Stabilizer• Vertical Stabilizer• Elevator

Fuselage• The body of the airplane that all the other

parts are attached to.

• Can be made of many different substances such as aluminum or wood.

Wings• The part of the plane that creates lift and

controls roll.

• Has a rounded leading edge and tapered trailing edge which helps create lift.

• The wing design uses Bernoulli’s Principle.

Yaw, Pitch, and Roll• Yaw – side to side

• Pitch – up and down

• Roll – rolling motion

Rudder• Provides side to side control of airplane.• Controls yaw.• Used for maneuvers in the air and for taxiing

on runway.

Rudder

The RUDDER controls YAW. On the vertical

tail fin, the rudder swivels from side to

side, pushing the tail in a left or right direction. A pilot usually uses the rudder along with the ailerons to turn the

airplane.

Rudder Controls Yaw

Yaw Around the vertical Axis

Elevator• In line with and behind the horizontal

stabilizer.

• Controls pitch.

Elevator

The ELEVATOR controls PITCH. On the horizontal tail

surface, the elevator tilts up or down, decreasing or increasing lift on the tail. This tilts the

nose of the airplane up and

down.

Elevator Controls Pitch

Pitch Around the Lateral Axis

Ailerons• Located at the top of the trailing edge

of the wings.

• Controls roll.

• Move up and down to control the direction of wind blowing over and under it.

Ailerons Control Roll

The AILERONS control ROLL. On the outer rear edge of each wing, the two

ailerons move in opposite directions,

up and down, decreasing lift on one wing while

increasing it on the other. This causes

the airplane to roll to the left or right.

Roll Around Longitudinal Axis

Horizontal Stabilizer

• Horizontal with the fuselage.

• Helps airplane maintain level flight.

Horizontal Stabilizer

Vertical Stabilizer

• Vertical to the horizontal stabilizer.

• Helps to airplane maintain level flight.

Vertical Stabilizer

Flaps• Located near at the trailing edge of the

wing near the fuselage.

• The Flaps increase lift.

Flaps

Propeller• Uses the principle of a wing to create

thrust to move the airplane forward.

• Can have different number of blades on propeller.

• Design is similar to an airfoil.

Engine:-• Turns the propeller at high RPM’s to

increase thrust.

Cessna Skyhawk Engine Jet Engine

DEMONSTRATION ON WORKING OF ENGINE

Landing Gear• A frame with wheels that allow the plane to

takeoff and land.• Some airplanes have retractable landing

gear. Landing Gear

Nose Gear• The front landing gear when the plane

has three wheels to land.

Nosegear

• The short answer is - No, they cannot stop in mid-air. Even though it appeared as the plane was not moving, it is unlikely that its forward motion was completely stopped. At a distance, very large planes can appear to be nearly stationary, especially at the relatively low speeds found during a landing approach. This effect can be made much more apparent depending on the angle from which you observe the plane - from the front or rear, the apparent motion would be very small. The distance from you to the plane also makes a difference.

Whether Flight Can stay Stationaryin Air?

Whether Flight Can stay Stationaryin Air? – Cont.• Air must be flowing past the wings in order to keep

the aircraft aloft.• In very unusual circumstances, it could conceivably

remain stationary relative to the ground—if it were flying directly into a very powerful headwind, for example. That doesn't actually happen in practice, however.

• But - it would take a very, very fast wind to keep any airliner in the sky completely stationary - more than 100 mph, probably. In a wind of that speed, planes would not be taking off or landing.

Launch Video

• If there were no wind at all, then the ground speed and the airspeed would be the same. When a plane flies into the wind, the airspeed is higher because of the added speed of the blowing wind across the wings. If the wind were blowing very hard, then the plane might have sufficient airspeed to maintain the needed lift to remain in the air, while the ground speed could be very slow.

Whether Flight Can stay Stationaryin Air? – Cont.