A whirlpool

Device description:

The device shows the behavior produced by causing the particles to rotate.
http://cngsystem.pl/pl/realizacja/wir-wodny/

Phenomenon:

The rotating rotor sets in motion the liquid particles next to it. These in turn move adjacent ones so that eventually all the liquid reacts to the rotating impeller. A vortex is formed in the liquid. The regular movement of the liquid, with a speed that decreases towards the vessel walls, is called laminar flow, and the chaotic movement of the liquid that occurs when the handle is stopped turning is an example of turbulent movement. The participant's task is to set the liquid in motion with a crank, and then observe the phenomena occurring in the tank.

How to perform an experiment?

To observe a physical phenomenon, the user turns the crank and observes the liquid in the tank.