Slowly winding the crank, set the rotor into rotation. Gradually, increase the speed of rotation of the rotor. Observe the behavior of the liquid.
How does it work
The spinning rotor sets the liquid particles, occurring within its reach, into motion. These, in turn, move the neighbouring particles and the whole liquid responds to the spinning movement of the rotor. The liquid produces a whirlpool. When we observe the ball inside, we can find out what is happening with an item that is placed near the whirlpool.
An even movement of the liquid, at a speed in which the value gradually decreases towards the walls of the vessel, we call a laminar flow. And the chaotic movement of the liquid, which appears after you stop spinning the crank is an example of a turbulent flow.
Whirlpools may form behind an object washed over by water. There are known instances of drowning as a result of being sucked in by a whirlpool near breakwaters on the seashore. When a whirlpool sucks you in, the best way to survive would be to dive and then to resurface just by the whirlpool.