[Ank]

Hey Guys,

I am simulating a single tube of 325 mm length and 25 mm diameter kept inside a closed box of 2 m X 2 m X 2 m dimensions filled with air. I am simulating air as the perfect gas (compressible model). The tube is kept at 350 K temperature and air is at 300 K.

I am using buoyantPimpleFoam solver in Openfoam 2.0.0. The pressure is atmospheric at the tube and at the walls of the container, the velocity is no slip everywhere.

The problem is with the convergence, I am getting a fluctuating residuals for velocity and pressure. The residuals varies from 1e-02 to 1e-04, but it is not converging. The velocity vectors seems ok everywhere but the temperature range is showing 299.97 to 350 K, which should not go below 300 K (ideally).
I am taking a time step of 1e-05, and the meshing is tetrahedral (unstructured). I am using k-epsilon model as well as have tried SSTkOmega.

Please help me if you have any idea about this, I have tried every boundary conditions I could.

Thanks in advance