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AcuSolve Multiphase simulation

Hi there!

I am trying to simulate a flow of humid air running through an helical pipe. As the air flows, it gets cooled from a negative heat flux on the walls of the pipe.

Any thoughts on how can I approach this problem? Currently, I am not able to run the simulation because I get an error 'Negative absolute pressure for humid air'.

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acupro

Which physics phenomena are you trying to capture with the simulation? Can you add the .inp file and .Log file?

Emanuel_22552

hi!

I am trying to simulate the dehumidification of the air passing through the pipe. Right now I am trying to impose a low temperature on the walls that should easily condensate the water.

Unable to find an attachment - read this blog

ydigit

There are several issues with your setup.

Why do you have a mesh motion with ALE? I guess that was unintentional.

Also any reason for the pressure offset?

Try running with these two adjustments (no mesh motion and no pressure offset) and report if it works...

Emanuel_22552

I changed the pressure offset and then switched the fluid to laminar instead of turbulent. Now it seems that it works.

My reasons to use a moving mesh is because I would like to simulate the centrifugal force that comes from the fluid passing through the helical tube.

I am adding the .inp file and the .log, let me know if my approach is wrong.. thanks!

Unable to find an attachment - read this blog

ydigit

Why are you using the pressure offset in the first case? I would remove it, unless you know why you introducing it. Also the current value of 10135 seems really odd (assuming you meant it 101325 = 1bar?).

Keep turbulence (default SA model) on, as that generally helps with convergence.

Mesh motion is needed when there is some explicit movement of a part (say FSI or rotating fan or flexible body). In your case I do not see a reason to enable mesh motion.