[dpitz]

Hi,

I'm running a buoyant rotating flow in Fluent using an unsteady 2D axisymmetric model. My geometry is a cylinder with adiabatic side walls, heated outer cylindrical wall and cooled inner cylindrical wall. Even though the residual of the energy equation is small (<10^-8), the energy entering the cavity does not equal the energy leaving it (the difference between the heat transfers is sometimes 25% of the total energy).

To investigate the cause of the problem I tried to run a simple conduction problem, with no rotation and no gravity. The temperature profile in the radial direction is correct, but still the energy balance is not zero. For this simple case the heat transfer rate at the outer wall is 5.35 W and -4.93 W at the inner wall, using a 100x100 mesh refined near the walls. For such a simple case I would expect the energy balance to be very close to zero, which is not the case.

Does anyone know what is wrong?

Thank you.