Open Inner Region could not be created

Project Support
1

Hey

I’m trying to simulate a simple cooler for a Mosfet and have already spent 10h trying to understand what is going on and adjusting stuff. My problem is, that I always get an error if I try to create an open inner region.

Here is a picture of what the heatsink will look like in real live:

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For the simulation I used a half-cut as it is symmetric and I built a box around the Heatsink with a fan-housing shaped inlet on the top and an outlet which should be similar to reality where it will open to the air.

image
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Now the Problem is that the open inner region fails, unless I make a gap between the fan inlet on the top and the heatsink. I made the gap really small (0.01mm) but then the simulation failed, and the mesh is unnecessarily fine on this 0.01 plane. I may get the simulation working with a bigger gap, but then the air will move differently then it should. Has anyone a idea why the inner region fails with no gap in between, I mean it is still all connected. BTW I already tried redrawing it to make sure, that there are no small errors in the design, that could lead to that problem.

Thanks in advance,

Dave

2

Hi Dave and very interesting application!

@cfd_squad (@DaleKramer & @Retsam), could you please assist here and give our user some guidance?

All the best!

Jousef

3

Hey @dcarminati,
im not sure :confused:, but can you do a boolean operation at your cad model, to merge all bodys to one ?
Maybe we can avoid this clipping.

grafik
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I not sure if this fixes the problem.

Best regards
Kai

4

Hey @Kai_himself,

The whole housing already is one body and I need it to be separate from the heatsink as I will assign different materials for the conjugate heat transfer simulation afterwards, or am I misunderstanding your suggestion?

I can try if it fixes it for the open inner region, but I wont be able to do the simulation afterwards, at least I wouldn’t know how.

[UPDATE:] I just tried it and it wont even start the operation, it stays at the “Start” button, I uploaded the old model with separate bodies and it worked, so it is only a problem with merged model.

Thanks,
Dave