[Javieryrazusta]

Hi!

I am studying Natural convection between a steel cylinder to -12.5 ° C (boundary condition:wall) and the atmosphere at standard conditions (pressure outlet boundary condition).

The mesh is in 2D.

I am doing the simulation in Steady and using air as Boussinesq with a thermal expansion coefficient value of 0.00333.
As the Rayleigh number is greater than 10^8 I lowered the gravity and I used the first order scheme. This way I get a convergent solution. I am slowly going to approach the gravity value of 9.81, but when the gravity is 6.5 , I don´t obtain converged solution.

I don´t Know where is the mistake.



Any idea what is wrong?
As I can solve it?

Thank you very much!