Hello SimScale community,
I’m a power engineering student and want to learn how to create heat transfer simulations.
To get started I thought of a rather simple problem: Radiative heat transfer in a vacuum.
By reading in the forum and the help articles I started a Conjugated Heat Transfer Simulation and toggled on Radiation in the global settings. After defining the radiative properties of the Volumes (4 light bulbs, 2 Al Plates and Glass plate) and the Surface Temperatures, I set the pressure to 1E-7 Pa (UHV) and wanted to start a first simulation (Radiation from the Bulbs to the Al, conduction within Al and afterwards radiation on to the glass surface).
Now the error “No contacts exist as part of the simulation setup” occures. And of course, because I want to simulate radiation in a simple model, my bodies are not in Contact.
How do I avoid this error? Is contact between the volumes needed?
Thanks in advance for your help 
Hey there, and welcome to the forum!
Can you please share the project URL here so I can have a look at what is happening?
Thanks for the link!
The error was most likely due to the disconnection between the solid bodies, and I assume it is solved now by the addition of the flow volume.
Sadly, we currently do not support vacuum modeling. Would an air flow region be valid for your case?
Yes I solved the initial problem by adding the flow volume. I tried to achieve vacuum conditions by putting air into the flow volume, but with a pressure of 1E-7 Pa. I guess thats the reason why the simulation is still failing, because air flow simulation under such pressure conditions lead to extremely small currents, which might be to much calculation effort.
Do you have any tipps for me how I could aproximate vacuum conditions?
I’m a little confused why vacuum conditions are not supported. It’s the most simple case for calculating energy transport processes, isn’t it?
Greetings
thanks my issue has been fixed.
