Helicopter PNG

Helicopter PNG

Helicopters can take off and land vertically and hold steady in the air. The flying principles of helicopters and airplanes are essentially the same. In order to obtain gripping force in aircraft, the aircraft is moved in the air. However, since the wing is attached to the fuselage, it is in a fixed structure. But in helicopters, the wing is not fixed, it is movable. In other words, a rotating wing, that is, a propeller, is used in helicopters to obtain lift. The propeller consists of two or more blades. The profile of the propeller blade is the same as the profile of the aircraft wing. The helicopter's engine turns the blades. As the pallets move in the air, low pressure occurs on their upper surfaces and high pressure on their lower surfaces. This pressure difference creates the bearing force. With the increase in the number of revolutions of the blades and the angle of attack (the angle of meeting the air of the blades), the magnitude of this carrying force also increases. In the opposite case, it decreases. When the lift force is equal to the weight of the helicopter, the helicopter stays in the air. When large, it rises vertically. When it is less, it descends vertically.

When the plane of rotation of the propeller is tilted, that is, the direction of the lift force created by the propeller is changed, the helicopter moves forward - backward and right - left. Thus, the helicopter is provided to move in the air. Since the propeller is constantly rotating (due to the moment it creates on the fuselage), it also tries to rotate the helicopter's body. To prevent this, a smaller propeller is used at the tail of the helicopter. The propeller in the tail absorbs the torque on the body. In addition, the rotation of the body can be achieved by changing the amount of damping.