SimScale CAE Forum

Combined heat transfer in a bioreactor

Good morning my friends,

Could you please help me with the following error:

“Inconsistent definition of interface: this happens when one side of an interface is assigned to a boundary condition. You can avoid this by removing interface faces from boundary conditions.”

Description of my problem:

I’m trying to apply the Conjugate Heat Transfer Analysis analysis to a problem involving a water-containing bioreactor. I intend to understand how the heat distribution is given along it. I need to observe how natural convection currents behave near the wall and in general. The boundary conditions, initials and other settings are in my project titled “Natural Convection in a Bioreactor3”. [


I have already configured the problem but errors are still encountered. I wish you could take a look at my analysis, and see what I’m doing wrong. Is this type of analysis correct? Do I have to use another type of analysis, for example, the Convective Heat Transfer with Buoyancy? @jousefm, @vgon_alves

Hi @Pedro_Henrique,

I got your intention with this project, but the project link is not working and I want to take a look at this before to give you a feedback, because you may be having more than one inconsistency here.

I will be waiting for the new link, and thanks for tagging me.



1 Like

Good Morning,

Thank you for responding.

Follow the link:

Hi @Pedro_Henrique

The problem you encountered occurs when you have two bodies with touching interfaces and a certain boundary condition is assigned to only one side. This throws an error because otherwise it may result in physically impossible scenarios such as an infinite temperature gradient at the boundary.

To fix the problem, try either defining the boundary condition for both sides of the interface, or for a temperature boundary condition, replace it with a volume heat source instead of defining a surface heat flux/surface temperature boundary condition.

Edit: I just had a quick look at your model and you should also be careful because you have partial interfaces in your model; this means that two interfaces are not exactly the same size in which case simscale does not automatically assign them and you have to do so manually otherwise no heat transfer will occur between them. As a rule of thumb, when building your CAD model you should work hard to avoid partial interfaces as they are liable to cause you problems.


Thank you @ Roy_g for your contributions. I will review these partial interfaces.