Let a ball follow the flow of water in the channel, which has been built on different levels and flows into the large barrel.
Using the different obstacles to dam up the Water channel, you can create swirls of water in front of the obstacles. Swirls will also form in the backwash created behind the obstacles.
When the depth and width of the channel are changed by the obstacles, it changes the speed and position of the water and the swirl is created. This is called turbulence. After a while, the larger swirls will often create smaller swirls of their own. The kinetic energy of the swirl will start to generate thermal energy after a while. The currents and swirls are constantly transported to new areas of the channel.