Electronic Cooling Problem with Boundary Conditions

Hi There

I try to simulate different heat sink design with the same conditions to see the performace from the heat sink design. For this I was build an Case, an camber, heat sink and power components.

In my case the fan will place at the inlet (inlet is were the camber are).
If I try to start the simulation I get an error after 10min:
Maximum number of iterations exceeded when calculating temperature from a thermodynamic potential. This may be caused by low-quality mesh producing unrealistic pressure in a few cells or inappropriate boundary conditions, fluid properties or time step. Inspect fields for large values in the last time step.

I would guess it is a problem with my boundery condition (because I just was trying to set something which make possible3 sens :wink: (it is my first simulation))

Waht I want to simulate:

  • I have an Cannel with an inlet an an outlet for the air.
  • inside the cannel is an heat sink with some power components
  • At the inlet is an fan
  • at the outlet is nothing (free room)

I guess I do something wrong with the boundery conditions.
May be someone can help me.


Hello Sascha,

To learn how to find and solve mesh issues, please follow these articles:

Hi I stillhave a problem to start my simulation, I hope you can Help me.
Here is what I was try to do:

  • remove the corners at the heatsink → with this it was not able to finish the Mesh calculation (need more Cores)
  • reduce the size of the Simulation device and remove the corners… same result
  • let the coners and do the mesh calculation by reduce size… Mesh was able to calculated after increase the Mesh size
  • With this new Mesh I get the next error, but in this case I don’t see why

Here are the link, I hope ypu can help me:


Hi Sascha,

I will show this error to the dev team and find out what is the source.

In the meantime, could you please try to run your model in the Conjugate Heat Transfer v2 solver?

Thank you, I will try it.

I get one question at this point (just to get sure):
The possible contact specification and also the Boundary sepcification are different to Conjugate Heat Transfer (V1). For contact specification I was able to calculatet the new value (1/Thermal Resistor to Thermal Conductivity) ok. But at the boundary condition I’m a littel confusing because at the previus simulation I was able to the the output vilocity and pressure input, now it is exact the opposide, but any way I try some thing.
But one point, pressure outlet, the pressure I can specified mean the pressure at the output?
Like, if i have a case with a fan at the inlet, and the outlet is in a “normal” room like i my lab, then the pressure at this lab or environment are is 1bar, or?
Or is the indicated pressure the pressure with which the air comes out of the case?

I hope you get what I mean.

And Thank you for help.