What is the principle of boomerang and why does it fly back?

The principle that boomerang can fly back is purely gyro effect. That is to say, due to the rotation during shooting, the spin axis of the boomerang will always point to a fixed point and precess around it, so the final trajectory forms an approximate circle.

The boomerang is also called boomerang, and there is a cooler name-boomerang. As the name implies, just fly back. It is also a hunting tool for Australian aborigines. The boomerang flies around an arc orbit and flies the longest distance in the shortest time without using other tools.

The shape of boomerang can be divided into V shape, cross shape and triangle shape. The tangent plane of its supporting wing makes the air lift of boomerang rise, thus stabilizing the fuselage. Unlike the propeller that starts to rotate when the plane or helicopter is completely stationary, the thrown boomerang will not only spiral, but also complete the air flight.

Every time the boomerang rotates, the upper wing moves in the same direction as the throwing direction, while the lower wing moves in the opposite direction. When the upper and lower wings rotate at the same speed, the boomerang can fly in the air at a faster speed. When a wing flies at a faster speed, there will be more airflow below. This phenomenon will generate lift, and the wing must exert more force to offset the increased mass. It's like someone keeps pushing the upper wing when the boomerang rotates.

Like a top, the boomerang rotates in a straight line. The lift and stability make the boomerang rise, and the rotation of the rotating shaft makes the boomerang fly back. In this way, just like a tilted bicycle wheel, the boomerang can rotate to the left or right continuously, thus making a circular motion and finally returning to the starting point.