LESSON 2

1. LESSON 2 Aerodynamics

2. Week 2 • Glue fin on • Colour the wing • Colure the tail • Cut out wing • Glue front of wing • Glue tail on • Glue wing on

3. Aerodynamics is the study of how air flows around objects. How Dose A Wings Lift the Plane?

5. Aerodynamics: What a Drag! When an object produces poor airflow, more energy is required to push it forward.

6. Four forces of flight Lift - upward Drag – down &backwardsWeight - downwardThrust - forward Forces of Flight

8. SHOW & TELL

9. LESSON NOTES

10. AIRCRAFT Most aircrafts that fly through the sky have wings to keep them aloft. As the wing cut swiftly through the air, they develop a strong upward force called lift. This force supports the weight of the aircraft, holding it up in the air. Wings generate more lift when moving quickly through the air AEROFOIL A wing is an aerofoil, which means it has a special shape that enables it to fly. The topside is curved and the underside is almost flat- so making the topside longer than the underside. As the wing cuts through the air, it deflects the air. Due to the wings shape, the air flowing above the wing moves faster then the air flow below. Because air pressure drops more as air moves faster, the air below the wing has a greater pressure, pushing up the wing. Control An aircraft also needs a tail in order to fly. The vertical fin and horizontal tail plane keep it stable.to control the air craft height and course, the pilot operates the following: ailerons on the wings, and a rudder and elevators on the tail Aerodynamics: What a Drag! Aerodynamics engineers study the way in which air flows around objects. One objective of aerodynamic studies is the design of shapes that offer the least resistance to the flow of air. Air offers a resistance to any object moving through it. Air resistance is influenced by the shape of an object. If a moving object is streamlined, the air will flow around it smoothly and cause less drag,

11. The Gift of Lift As long as weight is greater than lift, you're grounded. But if you can create lift greater than your aircraft's weight, you're ready for takeoff. Simple enough, but easier said than done. Unlike weight (which, thanks to gravity, is always exerting itself), lift isn't exactly self-motivating. We have to create it ourselves. Generally, we do this by forcing air around an "airfoil," like a wing. Thrust or Bust Thrust is a mechanical force that propels objects forward. Aircraft create thrust in different ways. We can't be sure how your chosen craft will work, but Newton's third law of motion ("to every action there is an equal and opposite reaction") will no doubt be key. By propelling gases, such as plain old air, backward, an aircraft's engines generate the thrust that pushes them forward. Jets and rockets use explosive chemical reactions to blast gases backward, and all that gas backwardness generates equal and opposite forward thrusting. Propeller-based aircraft, on the other hand, use internal combustion engines to rapidly spin blades that behave like rotating airfoils. The faster a propeller spins, the faster it propels air backward--and backward blowing leads to equal forward thrusting. What a Drag If weight is a downer, drag is a stopper. Drag is the aerodynamic force that opposes an aircraft's motion through the air. Air is something and not nothing after all. And when any two objects slide past each other, they generate friction, which siphons off kinetic energy (motion) and converts it into heat. The more friction, the more energy the sliding objects lose, and the more they slow down. Major Tom to Pound Control When it comes to flying, weight is actually the easiest force to deal with, because its effects are relatively constant and easy to measure. Every aircraft has a mass. We measure gravity's pull on that mass as weight, and, since gravity is basically constant here on Earth, so is the aircraft's weight (at least until it starts adding passengers, or burning fuel). Getting an aircraft airborne is basically a matter of generating enough lift to overcome its weight. Of course, one way to help do that is to lighten the load as much as possible from the start. Hence all aircraft parts are made to weigh the minimum while still safely doing their jobs, and airplane designers try to remove all unnecessary components from their crafts. Keeping an aircraft "fit and trim" simply makes the job of lifting it easier.

12. FlapsIn general, the wings on most planes are designed to provide an appropriate amount of lift (along with minimal drag) while the plane is operating in its cruising mode (about 560 miles per hour, or 901 km per hour, for the Boeing 747-400). However, when these airplanes are taking off or landing, their speeds can be reduced to less than 200 miles per hour (322 kph). This dramatic change in the wing's working conditions means that a different airfoil shape would probably better serve the aircraft. To accommodate both flight regimes (fast and high as well as slow and low), airplane wings have moveable sections called flaps. During takeoff and landing, the flaps are extended rearward and downward from the trailing edge of the wings. This effectively alters the shape of the wing, allowing the wing to turn more air, and thus create more lift. The downside of this alteration is that the drag on the wings also increases, so the flaps are put away for the rest of the flight.