[mb_ing]

Hi everybody,
I want to simulate the free convection of a milling machine and its surrounding air. The machine itself is located in a hall modeled as a block around the machine (not visible in the pictures).
One aim is to get the Heat Transfer Coefficient of the machine surface.
Unfortunately, I just have the temperature of heating sources as boundary conditions on the surface (e.g.: Spindle). Therefore I have unrealistic local gradients between the regions with different temperatures and consequently problems with the HTC in these regions (see pictures). Additional information about the scene: HTC has a scaled color bar.
Does anybody know, how to create a smoother temperature distribution/boundary condition between the critical regions?
Thank you a lot in advance!