Boussinesq - natural convection
 

Boussinesq approximation is used to give density variation with temperature. Everyone says that Boussinesq can be used only for small temperature variation : 1. Can you gave me the value of that maximum temperature variation? (different lues in different papers) 2. What does "temperature variation" or "temperature difference" means? For exemple : Natural convection on a vertical plate uniformly heated. Is the temperature difference between the wall and the fluid or just the temperature difference in the fluid flow (I saw both definition). Thank you

Re: Boussinesq - natural convection
 

why don't use ideal gas.

Re: Boussinesq - natural convection
 

I use Incompressible Ideal Gas, but i try to find a paper where limit of Boussinesq is shown (5% for Beta*delta(T) that what I used to ear but I never read it on a paper). Incompressible Ideal Gas not so easy to use. Lot of different depending the operating density you use. It can be unphysical flow when Fluent computes the density as a mean value on all cells. More realistic when I give the operarting density but I don't know what I have to take as specified operating density. If someone have an idea.... (density at the ambiant temperature?)