[abu250feldman]

Hello everyone,

I am simulating a problem involving natural convection inside an enclosure with internal heat sources. The enclosure is filled with oil. The heat is dissipated through the enclosure walls (outer wall with heat transfer coefficient and ambient temp was defined on the external enclosure surfaces).
The main problem is that it takes a very long time for the oil temp. to reach SS (the time constant is app. 13000 sec). I have tried flow freezing but gets inconsistent results.

Is it possible to use flow freezing for natural convection (I used the periodic approach to allow the temp. field to effect the velocity field and vice versa)? What is the recommended approach for solving natural convection problems with very different time constants? Any help/advice will be appreciated.