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Pressure, Temperature, and Material Deformation Coupling

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Hi,

I'm very new to COMSOL and can't seem to figure out how to solve this problem or find any tutorials for it. I essentially have a sealed hollow box (filled with air) with thin walls. I am trying to model how changes in the external temperature and pressure affect the deformation of the thin wall and how both of those affect the temperature and pressure of the air inside the box (internal pressure is the most important parameter I need to model). I have a solid mechanics physics study that could succesfully model the deformation if I prescribed an internal pressure and external pressure, but did not seem to model changes in the internal pressure caused by the change in volume from the deformation. I then tried to add a Heat Transfer in Fluids model in an attempt to get pressure, but can only get temperature and again no pressure modeling. I then tried to couple the two using multi-physics. When I run the coupled study, I jut get the Temperature results and no deformation results or pressure results. Does anyone have any suggestions for how I can get the pressure to be a variable output and/or good tutorials that could help with coupling solid mechanics with fluid pressure and temperature changes? Am I using the wrong physics options?

Much thanks, Lyndie


3 Replies Last Post Jun 19, 2019, 2:22 a.m. EDT
Henrik Sönnerlind COMSOL Employee

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Posted: 5 years ago Jun 17, 2019, 9:56 a.m. EDT
Updated: 5 years ago Jun 17, 2019, 9:56 a.m. EDT

Hi Lyndie,

I think the following blog posts can help you:
https://www.comsol.com/blogs/computing-controlling-volume-cavity
https://www.comsol.com/blogs/modeling-hydrostatic-pressure-fluid-deformable-container

Regards,
Henrik

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Henrik Sönnerlind
COMSOL
Hi Lyndie, I think the following blog posts can help you: Regards, Henrik

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Posted: 5 years ago Jun 17, 2019, 11:43 p.m. EDT
Updated: 5 years ago Jun 18, 2019, 7:49 p.m. EDT

Hi Henrik,

Thank you! I think I was at least able to get it so the pressure can vary internally with just the static load (no thermal effects yet). However, I can't actually view the final pressure value or plot it. (I don't need the contact pressure, I need the pressure of the air inside the box. Any suggestions for how to extract the computed value/ plot what the presure is like?

Thanks, Lyndie

Hi Henrik, Thank you! I think I was at least able to get it so the pressure can vary internally with just the static load (no thermal effects yet). However, I can't actually view the final pressure value or plot it. (I don't need the contact pressure, I need the pressure of the air inside the box. Any suggestions for how to extract the computed value/ plot what the presure is like? Thanks, Lyndie

Henrik Sönnerlind COMSOL Employee

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Posted: 5 years ago Jun 19, 2019, 2:22 a.m. EDT
Updated: 5 years ago Jun 19, 2019, 2:22 a.m. EDT

Hi Lyndie,

Maybe I do not understand the question. If you have been able to apply the internal pressure as load, that same expression should be possible to evaluate during result presentation too. Any variable or expresssion can be evaluated.

Regards,
Henrik

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Henrik Sönnerlind
COMSOL
Hi Lyndie, Maybe I do not understand the question. If you have been able to apply the internal pressure as load, that same expression should be possible to evaluate during result presentation too. Any variable or expresssion can be evaluated. Regards, Henrik

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