Natural convection is not converging
 

Hi all,

for my master thesis i need to simulate a heatingsystem for a church. Therefore i simplified the construction to a big room with one block of heat source in the middle. There is a small heat flux loose through the walls an i already added the model S2S-Radiation (gray thermal radiation).

The velocity vectors make sense to me, but the block doesnt heat up the surrounding space.

I am using the version STAR-CCM+ 2022.1 Build 17.02.007.

The phsyics models are:

All y+ wall treatment
gas
gradients
gravity
gray thermal radiation
ideal gas
K-Omega Turbulence
Radiation (S2S)
RANS
Segregated Flow
Segregated Fluid temperature
Solution interpolation
SST (Menter) K-Omega
Steady
3D
Turbulent
View factors calculator
Wall distance

Any ideas what i could do?

Thank you in advance!

what are the boundary conditions? maybe the flow is because of the boundary conditions?
PS:I was once faced with a similar problem, as the coolant can't bring away the heat of batteries, then I used impress/weak contact to create interface between them and the problem is solved.