HOW DOES HELICOPTER FLY? , BASIC PRINCIPLE AND WORKING OF CHOPPER

Helicopter is very common to known for a person, we seen many helicopters flying in the sky. many of us have sited inside a chopper but do you know the working of chopper, on which basic principle it fly. here is a brief description of principle and working of  helicopters that will surely make you know the working and basic idea used in helicopters. its not the whole working of a helicopter but in brief because if we try to write our all knowledge then you will become bored by reading like a book

Principle :

It is based on the principle of Bernoulli’s principle which says that whenever there is increase in pressure there will be decrease in velocity and vice versa.

Helicopter also works on same principle, its main rotor decreases pressure above it which makes it fly in the air and gives the helicopter a speed but the rotation of helicopter is controlled by tail rotor.

Working :

Helicopter, Lift is obtained by means of one or more power driven horizontal propellers which called Main Rotor. When the main rotor of helicopter turns it produces lift and reaction torque. Reaction torque tends to make helicopter spin. On most helicopters, a small rotor near the tail which called tail rotor compensates for this torque. On twin rotor helicopter the rotors rotate in opposite directions, their reactions cancel each other.

Main Rotor :

The lifting force is produced by the main rotor . As they spin in the air and produced the lift. Each blade produces an equal share of the lifting force. The weight of a helicopter is divided evenly between the rotor blades on the main rotor system. If a helicopter weight 4000 lbs and it has two blades, then each blade must be able to support 2000 lbs. In addition to the static weight of helicopter ,each blade must be accept dynamic load as well . For example, if a helicopter pull up in a 1.5 g maneuver (1.5 time the gravity force), then the effective weight of helicopter will be 1.5 time of static helicopter weight or 6000 lbs. due to gravitational pull.

Tail Rotor :The tail rotor is very important. If you spin a rotor with an engine, the rotor will rotate, but the engine and helicopter body will tend to rotate in opposite direction to the rotor. This is called Torque reaction. Newton's third law of motion states , " to every action there is an equal and opposite reaction" . The tail rotor is used to compensates for this torque and hold the helicopter straight. On twin-rotors helicopter , the rotors spin in opposite directions, so their reactions cancel each other.

The tail rotor in normally linked to the main rotor via a system of drive shafts and gearboxes , that means if you turn the main rotor , the tail rotor is also turn. Most helicopter have a ratio of 3:1 to 6:1 . That is, if main rotor turn one rotation , the tail rotor will turn 3 revolutions (for 3:1)or 6 revolutions (for 6:1). In most helicopter the engine turns a shaft that connected to an input quill in the transmission gearbox. the main rotor mast out to the top and tail rotor drive shafts out to the tail from the transmission gear box.

Hope you will like my post and thought.

Reference - thaitechnic.com