Computational model for solution convection due to density difference

[streeters]

I am a corrosion engineer and I am trying to model localised corrosion, where saturated (dense) salt solutions flow over less dense solutions.

I am aware of the Rayleigh-Benard convection model, where hot water rises and cool water sinks (e.g. boiling water on a hob). Is there a well known model that deals with this effect using concentration variation rather than temperature?
I'm cautious of using RB and imposing unexpected thermal effects

 

[Illmatic1]

.There is a model known as the Stefan-Maxwell equations which deals with diffusion and convection of multiple components in a binary solution, such as the flow of salt solutions over less dense solutions. The Stefan-Maxwell equations describe the transport of mass for each species in the solution and can be used to model localised corrosion, as long as the driving force between the two solutions (i.e. the difference in concentration) is known.