How Aeroplanes fly ! right from Wright Brothers to now newly Jet planes........
those are.......
- Lift -results in upward movement of plane.
- Drag -resistance of air in both upward and forward movements.
- Thrust -results in forward movement of plane.
- Gravity -gravitational force on plane.
How these forces are generated ?Thrust : It is generated by the aeroplane s engine located in the front portion of the plane run by using propellants.
Drag : It is mainly due to the frictional force of the air on the body of aeroplane. as the plane moves forward, this force acts opposite to this movement ie in backward direction and when the plane lifts this force acts in downward direction.
Gravity : It is due to the Weight of the aeroplane.
Lift : It is the force acted upward on aeroplane when it in flight. the wings of the plane are responsible for the lift of the plane.
How the Wings generate the Lift ?
The generation of lift is sometimes a disputed theory, but there are some key factors that are mainly responsible for its basic principle.
A cross section of a typical airplane wing will have the top surface to be more curved than the bottom surface. This shape referred as 'airfoil' or 'aerofoil'.
During flight air flows over and beneath the wing. Any given portion of air gets split in two regions hits the leading edge of the wing, and both halves of that portion actually meet up again at the same moment as they come off the trailing edge of the wing.
So because the air moving over the top of the wing has more distance to cover because of more curvature in the upper region , in the same amount of time as the air passing below the wing, it has to move faster, typically as shown below.
As the air in the upper region has to move with faster speed,it will be lesser denser than the air passing below the wing. therefore the pressure above the wing is usually lesser than the one that is below the wing. Therefore the pressure below the wing pushes the wing upwards as more air ceases to the wings.
The main factor the lift is Angle of Attack, is the angle at which the wings sits in relation to the horizontal airflow over it. As the angle of attack increases, more lift will be generated, up to a certain limit a smooth overflow is broken up.
Controlling the Aeroplanes movement :
The main parts of the controlling system of aeroplane are :
- Ailerons.
- Rudder.
- Elevators.
- Flops.
To understand ,imagine 3 axis (the blue dashed lines) running through the plane.
One runs through the center of the fuselage from nose to tail (longitudinal axis),
one runs from side to side (lateral axis) and
the other runs vertically (vertical axis).
All 3 axis pass through the Center of Gravity (CG), the airplane's crucial point of balance.
Whenever the plane in its flight, it will rotate about these axises.
* Located on the rear end of the wing, the ailerons control the airplane's roll about its longitudinal axis.
* Each aileron moves at the same time but in opposite directions ie when the left aileron moves up, the right aileron moves down and vice versa.
* The ailerons are controlled by a left/right movement of the control stick, or 'yoke'.
2) Rudder :*The rudder is located on the back edge of the vertical stabilizer, or fin, and is controlled by 2 pedals at the pilot's feet.
* When the pilot pushes the left pedal, the rudder moves to the left.
* The air flowing over the fin now pushes harder against the left side of the rudder, forcing the nose of the airplane to yaw round to the left.
3) Elevators :
* The elevators are located on the rear half of the tailplane, or horizontal stabilizer.
*They cause a subtle change in lift when movement is applied which raises or lowers the tail surface accordingly. In addition, air hitting deflected elevators does so with exaggerated effect that forces the airplane to tilt upwards or downwards.
* Moving the elevator up will cause the airplane to pitch its nose up and climb, while moving them down will cause the airplane to pitch the nose down and dive.
4) Flaps :
* Flaps are located on the trailing edge of each wing, between the fuselage and the ailerons, and extend outward and downward from the wing when put into use.
* The purpose of the flaps is to generate more lift at slower airspeed, which enables the airplane to fly at a greatly reduced speed with a lower risk of stalling. When extended further flaps also generate more drag which slows the airplane down much faster than just reducing throttle power.
* Although the risk of stalling is always present, an airplane has to be flying very slowly to stall when flaps are in use at, for example, 10 degrees deflection.
So all these factors are why and how airplanes fly.
Radio control model airplanes can of course be more simple, just have rudder and elevator control or perhaps just rudder and motor control. But the same fundamental principles are apply to all airplanes, regardless of size, shape and design.
source: rc-airplane-world.
