Project Aeroplane (Short Review)

Student em National Institute of Technology Calicut
3 de Oct de 2013

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Project Aeroplane (Short Review)

  1. A Review on Airplane Parts and Aerodynamics
  2. 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?
  3. 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
  4. 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.
  5. 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
  6. 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
  7. 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
  8. Engines (either jet or propeller) typically provide the thrust for aircraft. When you fly a paper airplane, you generate the thrust.
  9. 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
  10. As an airplane moves forward, the airflowAs an airplane moves forward, the airflow splits up into two separate flowssplits up into two separate flows Before We Begin…
  11. Bernoulli’sPrincipleDefined • 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.
  12. Bernoulli’sPrinciple • 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 which occurs at the top, exerting a lifting force on the entire wing • Pressure imbalance produces an overall upward force
  13. Bernoulli’s Principle Diagram
  14. 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!
  15. Conservation of Energy (Bernoulli’sPrinciple) 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 and motional 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
  16. Bernoulli’sTheory 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.
  17. 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
  18. FactorsWhich Affect theAmount 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
  19. Various Parts of Aircraft
  20. Airplane Parts • Fuselage • Wings • Ailerons • Flaps • Rudder • Horizontal Stabilizer • Vertical Stabilizer • Elevator
  21. 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.
  22. 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.
  23. Yaw, Pitch, and Roll • Yaw – side to side • Pitch – up and down • Roll – rolling motion
  24. Rudder • Provides side to side control of airplane. • Controls yaw. • Used for maneuvers in the air and for taxiing on runway. Rudder
  25. 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
  26. Yaw Around the vertical Axis
  27. Elevator • In line with and behind the horizontal stabilizer. • Controls pitch. Elevator
  28. 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. ElevatorControls Pitch
  29. Pitch Around the Lateral Axis
  30. 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.
  31. 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.
  32. Roll Around Longitudinal Axis
  33. Horizontal Stabilizer • Horizontal with the fuselage. • Helps airplane maintain level flight. Horizontal Stabilizer
  34. Vertical Stabilizer • Vertical to the horizontal stabilizer. • Helps to airplane maintain level flight. Vertical Stabilizer
  35. Flaps • Located near at the trailing edge of the wing near the fuselage. • The Flaps increase lift. Flaps
  36. 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.
  37. Engine:- • Turns the propeller at high RPM’s to increase thrust. Cessna Skyhawk Engine Jet Engine
  39. Landing Gear • A frame with wheels that allow the plane to takeoff and land. • Some airplanes have retractable landing gear. Landing Gear
  40. Nose Gear • The front landing gear when the plane has three wheels to land. Nosegear
  41. • 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 Stationary in Air?
  42. Whether Flight Can stay Stationary in 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
  43. • 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 Stationary in Air? – Cont.

Notas do Editor

  1. Now going back to the simple ingredients for creating lift – air and motion. Something needs to get that wing moving through the air before it can create lift. That’s where thrust comes in.
  2. A wing is shaped and tilted so the air moving over it moves faster than the air moving under it. Bernoulli’s Principle says that as air speeds up, its pressure goes down. The 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! Illustration from “How Things Fly” (See Internet Resources)
  3. The sideward tug you feel on your car when you pass a large truck going in the opposite direction is caused by air pressure. The passing vehicles form a constriction that speeds up the flow of air, reducing the air pressure between them. (It makes no difference which is moving--the air or the vehicles. The result is the same.) The higher air pressure on the other side of the car pushes it toward the truck during the split-second as they pass.
  4. The wings generate most of the lift to hold the plane in the air. To generate lift, the airplane must be pushed through the air. The jet engines , which are located beneath the wings, provide the thrust to push the airplane forward through the air. Some airplanes use propellers for the propulsion system instead of jets. To control and maneuver the aircraft, smaller wings are located at the tail of the plane. The tail usually has a fixed horizontal piece (called the horizontal stabilizer) and a fixed vertical piece (called the vertical stabilizer). The stabilizers' job is to provide stability for the aircraft, to keep it flying straight. The vertical stabilizer keeps the nose of the plane from swinging from side to side, while the horizontal stabilizer prevents an up-and-down motion of the nose. (On the Wright brother's first aircraft, the horizontal stabilizer was placed in front of the wings. Such a configuration is called a canard after the French word for "duck"). At the rear of the wings and stabilizers are small moving sections that are attached to the fixed sections by hinges. In the figure, these moving sections are colored brown. Changing the rear portion of a wing will change the amount of force that the wing produces. The hinged part of the vertical stabilizer is called the rudder; it is used to deflect the tail to the left and right as viewed from the front of the fuselage. The hinged part of the horizontal stabilizer is called the elevator; it is used to deflect the tail up and down. The outboard hinged part of the wing is called the aileron; it is used to roll the wings from side to side. Most airliners can also be rolled from side to side by using the spoilers. Spoilers are small plates that are used to disrupt the flow over the wing and to change the amount of force by decreasing the lift when the spoiler is deployed. The wings have additional hinged, rear sections near the body that are called flaps. Flaps are deployed downward on takeoff and landing to increase the amount of force produced by the wing. On some aircraft, the front part of the wing will also deflect. Slats are used at takeoff and landing to produce additional force. The spoilers are also used during landing to slow the plane down and to counteract the flaps when the aircraft is on the ground. The next time you fly on an airplane, notice how the wing shape changes during takeoff and landing. The fuselage or body of the airplane, holds all the pieces together. The pilots sit in the cockpit at the front of the fuselage. Passengers and cargo are carried in the rear of the fuselage. Some aircraft carry fuel in the fuselage; others carry the fuel in the wings.