'Vacuum Chamber' simulation project by dheiny


#1

I created a new simulation project called 'Vacuum Chamber':

Copy of @pbonyhati's project - normal pressure outside, fixed faces.


More of my public projects can be found here.


#2

Hello David, I've got a question around the boundary conditions used:

I can see that you have applied 101350 Pa (or 1.0135 bar) to the outside of the model which is the normal athmospheric pressure on sea level.

How did you create the internal vacuum which causes the deformation?

thanks, Tillman



#3

Hi @tschmelzle,
modeling the vacuum is done basically the same way as it as the pressures are acting in reality.

When creating a vacuum, initially both sides (internal and external) are under atmospheric pressure, then the vacuum is created by removing the air from inside, resulting in zero internal and atmospheric external pressure. The zero internal pressure does not need to be modeled explicitly.

I hope this explained the setup from @dheiny well enough. If there are any additional questions I am happy to help!

Best,
Richard


#4

Hello Richard,
Thank you very much for your feedback! Much appreciated.

It is not 100% clear yet as I am not sure how to actually “remove the air”. In order to create the vacuum on the inside of the chamber do I simply assign the equivalent over-pressure to the outside of the chamber?
For example: To achieve a 0.5 bar vacuum on the inside of the chamber do I have to:

a) apply 0.5bar on the outside surface only OR
b) apply 1.5 bar to the outside surface of the chamber so that there will be:
- Inside: 1 bar (which does not have to be modelled explicitly)
- Outside: 1 bar + 0.5bar extra = 1.5 bar

regards, Tillman


#5

Hello @tschmelzle,
0.5 bar on the outside is sufficient (option a)) as by default the interior will have 0 bar.

Best,
Richard