I saw a lot of materials supposing that the Bernoulli's equation explains the curvature of a soccer ball: since the ball is spinning, two sides of the ball would experience different velocities, and due to Bernoulli's theory, the side with slower velocity generates a higher pressure and push the ball to the other side.

However, when we first learnt the Bernoulli's equation, one of the fundamental criteria is that it must be applied on the same streamline. And in the above case, the streamlines on the two sides of the ball are separated. So how does the Bernoulli's theory explain the curving-ball phenomenon? Is that a misconception?

  • $\begingroup$ The Bernoulli is applicable for a streamlined flow, no turbulence. But in this case, the flow becomes turbulent. The phenomenon is known as Magnus effect en.m.wikipedia.org/wiki/Magnus_effect Bernoulli is not a correct explanation of this phenomenon. $\endgroup$ – Tojrah Apr 23 '19 at 10:33