[userid42]

Hello,

From what I understand, Boussinesq Approximation:


holds for (Please see attachment for more details).

I am interested in simulating the fluid flow of two fluids that have different densities (Densities differ between 1 to 10%) and viscosities at a constant temperature.

Per the above equations:
,
So I am looking at a ranging from 0.01 to 0.1.

Would the Boussinesq approximation still be valid for the cases that I am interested in? I have read multiple threads from CFD-Online, and what I understood is that the approximation is valid as long as , but no range is specified.

Could someone clarify this point? If you have tried simulating flows of this kind, how did you approach the problem?

Thank you very much for your time!