Anyone please tell me the principle of a BOOMERANG???

Question

why a BOOMERANG comes back after throwing???

Answer 1

The previous answer is elegant proof the wikipedia cannot be trusted to give correct answers because it is written by common (unqualified) users. Bournelli's principle is NOT responsible for lift over an airfoil, as has been shown REPEATEDLY throughout modern history... and yet for some reason people cling to this myth like a five year old to a comfort blanket. I, on the other hand, have no use for such daliances of scientifical fancy.

The actual generator of lift over an airfoil is due to angle of attack. the boomerang is shaped such that the air strikes the bottom of one foil (creating upward lift via newton's law of equal and opposite reactionary force... NOT bournelli's principle) and the top of the other foil. this causes the boomerang to lean to one direction as it continues it's forward momentum. Properly shaped and thrown, the boomerang will maintain an angled flight with a rotational moment that will generate lift at an angle to the vertical path of travel... this will in effect pull the boomerang around in a circle as it travels, returning it to your hand.

Answer 2

A boomerang is a spinning curved wing. As it spins, the end of the boomerang travelling in the direction of motion is moving faster through the air than the other end - which is moving in the opposite direction. Therefore there is more lift at one end than the other. Because the boomerang is travelling in a vertical plane this extra lift pushes sideways on the faster moving half of the boomerang causing it to tilt. Because its spinning the boomerang also acts as a gyroscope and it trys to oppose the tilting by turning in the direction of tilt. The two forces combined result in a curved flight path.

Answer 3

Returning boomerangs consist of two or more arms or wings, connected at an angle. Each wing is shaped as an airfoil, air travels faster over one surface of an airfoil than the other, as the air is accelerated due to the curvature, thus creating lift, along what is roughly a plane which intersects the airfoil at a near right angle along the long axis of the wing.

These wings are set so that the lift created by each wing opposes the lift of the other, but at an angle such that the flight pattern is constantly shifted as the forces of lift, drag, speed, rotational inertia etc. 'attempt' to reach equilibrium.

This is what makes the boomerang 'return gracefully to the thrower, fluttering to a stop in his hand'... when thrown correctly. This is also what makes the boomerang 'rocket straight up into the air before plunging to its shattered doom'... when thrown incorrectly. With the exception of long-distance boomerangs, they should not be thrown sidearm or like a frisbee, but rather throw with the long axis of the wings rotating in an almost-vertical plane.