Is it possible to only set boundary condition only absorb inner radiation?

I have set a boundary condition which is a metal surface and i want to simulate its radiation from inner.

However, I also setted solar load at same time,

In the real life, the room is covered by other floors with 10 meters concrete so the heat exchanger wont absorb heat from sun.

But in this simulation i only buit the flow region model. Thus those heat exchanger absorbed a lot of heat from sun, the designed cooling facility becomes a sun heating facitlity, So i am wandering is it possible to make the surface only absorb one direction radiation.

Hello @weixuan_yu ,

I’m not sure if I understood the scenario, but it sounds like you would like to consider radiation in the simulation. If I understood correctly, there are several floors above the computational domain, essentially “blocking” the sunlight?

If that’s the case, wouldn’t turning solar load off help? You can still have “radiation” enabled.


Hello, Thank you for reply,
Here is the thing: those red region square in the picture, is the cooling panel. In the original design, that is a cooling facility, which is set to be a cold region for about 18℃.

Since I need to consider it absorb the heat through radiation , the radiation function is open.

However, I want to consider the solar load now.
In the real life , there are several floors above the model. It will block the solar radiation above. But in the simulation ,the sunshine is been absorbed by the cooling panel 100%, makes it with a very high temperature.

I want to ask if there is a way to add another layer, to block the solar radiation above.


The only wall boundary condition that is affected by external solar load is a “Derived heat flux” boundary condition (doc page). Is there any chance to set those boundaries with any other temperature configuration?


Hi, that boundary is designed to absorb heat (but from internal the room instead of the solar) and the whole simulation is about to get its energy absorption So i dont think i can do that.

Is there any way that i can cover it with another layer to prevent it from absorbing solar load?

Should be possible, yes. You can also set the contacts/boundaries of the “cover” to adiabatic, to prevent it from playing a role in the physics.


Sorry but how to do the “cover”?

That would require a CAD software.

Alright i got it here is the thing…

What I build i think is not construction but a model of air, So how it is possible to add a cover block by air, to cover another group of air. It doesn’t comply to the flow assumption correct?

In order to cover that air, I must add a solid part , but i only saw concrete, i didn’t saw insulative material, so I have to build like a model of concrete of several meters , too many pointless computing sources will be consumed this way.

Hi Weixuan,
I saw the recent post from @RicardoParis which sounds like a possible approach to the issue and then saw the comment about “i only saw concrete, i didn’t saw insulative material”.
So I did some research to assist.

I copied the project SimScale and looked at the solid materials available. You are right about concrete being available and there are other materials that have some insulating ability. However, you can create your own New special material and change the properties to suit.

As you can see from this image, my New special material is called ‘tytutu’.
It has unusual properties, so you can create your own specific insulating material :slight_smile:
I also confirmed this ability to create any New material, via the Simscale document, link attached below.


Hope this helps :slight_smile:

Kind regards