Hi mates,

I'm trying to make a very simple model for a pin losing heat through free convection to an environment. To account to for the buoyancy force, I have used the term "

**alpha*g*rho_air*(T-Tamb)**" (taken from a sample by FEATool).

For boundary conditions, I have used

**Temperature ** and

**Pressure ** for the vertical wall against warm plate.

For the top part I have used "

**Natural outflow**" with "

**convective heat flux**" and for the bottom part I have tried "

**convective heat flux**" and "

**Insulation**" with "

**Wall no slip**" and "

**Natural out flow**".

Neither of these conditions give me a stable answer. Anybody has any idea what's going wrong here? I have uploaded the file here as well.

pin_2D.fea
Thanks for your help beforehand.

PS: In the samples of FEATool for convection inside a box, I replaced the above-mentioned term with Pr.Ra for the Fy and it totally changed the results and velocity profile, but at least the model could converge.