Decades-Old Feynman Sprinkler Problem Solved by Mathematicians

Research reveals reverse sprinklers rotate in opposite direction when taking in water, contributing to understanding of fluid dynamics.

The Feynman Sprinkler Problem, a long-standing physics puzzle, has been solved by a team of mathematicians through precise laboratory experiments and mathematical modeling.
The problem involves understanding how a sprinkler operates in reverse, meaning water flows into the device instead of out.
The research reveals that a reverse sprinkler rotates in the opposite direction when taking in water compared to when it expels water, and the explanation behind this phenomenon is both subtle and surprising.
The researchers found that the two internal jets collide but not directly head-on, and their mathematical model illustrated how this subtle collision effect generates forces that cause the sprinkler to rotate in reverse.
While the practical applications of understanding the workings of a reverse sprinkler may be limited, the findings contribute significantly to the fundamental understanding of fluid dynamics and could be beneficial for harnessing climate-friendly energy sources.