Rythms of a Saline Oscillator

Abstract

A small vase with a saline solution and a small hole in the bottom is partially submerged in a larger container filled with distilled water. Various periodic regimes of exchange of water between containers can be established. The motion starts with a jet of salt water falling into the distilled water. After sometime, the apparently stationary motion breaks up and a jet of distilled water starts going up into the salt water, and a periodic regime is established for some time. The time for the initial discharge is much longer than the following oscillations. Eventually, the oscillation becomes asymmetric but it can last for over a day. Distilled water accumulates on top of the small container and salt water on the bottom of the large container until the motion stops. The frequency of oscillation depends on the area ratios, the relative volumes of water and the size of the hole. When perturbed, different regimes can be observed. The behavior can be compared to a Rayleigh oscillator. We thank the support of UNAM through project PAPIME PE104907.