Abstract
“Salt ngering” the phenomenon of the double-difusive convection has been studied experimentally.
We prepared a system with vertical density variation, which contains salt and sugar
solutions, separatedone from the other. The “salt finngers” appear at the interface between these
layers of salt and sugar solutions. The “salt fingers” have been observedby means of shadowgraph
technique.
With the aid of a computer and the video-capture technique, it was possible for the first time
to conduct a detailed investigation of the phenomenon. The geometric characteristics of the “salt
fingers” such as form, length and width have been investigated.
The way in which these quantities depend on the salinity and sugar concentrations, as well as
the thickness of the salt and sugar layers has been verified experimentally. We also verified the
predicted form of dependence of the average “salt fingers” width on its vertical length.
Keywords: Double-difusive convection; Hydrodynamic instability; “Salt finngers”