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-   -   Internal Static Pressure in a tank - ANSYS CFX (https://www.cfd-online.com/Forums/cfx/189108-internal-static-pressure-tank-ansys-cfx.html)

glik June 13, 2017 10:51

Internal Static Pressure in a tank - ANSYS CFX
 
1 Attachment(s)
Hello everyone,

I would like to make a tank for my internship.
My subject is "Numerical Simulation of a tank submitted to an earthquake".

I have some problems :

1) Inside my tank, I have water and air. But I have a problem with the interface when I had a horizontal acceleration to simulate the seism. Do I have to use "Free surface model" ? Or maybe it's the sizing mesh, but I have already do something about it.
I put a picture as attachment. In red the water, in blue air.

2) I can't add an internal pressure. In inizialization settings, I add it, but I can't see any changement in the post-proc.
Does someone have any idea ?

Thanks a lot

camposrf August 9, 2017 18:09

interface--> Definition
 
Quote:

Originally Posted by glik (Post 653021)
(...) I have a problem with the interface when I had a horizontal acceleration to simulate the seism. (...)

I had the same issue with the interface. I defined the volume fraction and obtain this:

https://www.cfd-online.com/Forums/at...tersurface.png

https://www.cfd-online.com/Forums/at...tkvfwater3.png


you can read more at my post
https://www.cfd-online.com/Forums/cf...f-command.html

glik August 16, 2017 12:07

Which condition did you use for the top ?
And with a thinner mesh it should be better ;)

camposrf August 17, 2017 09:16

approximation cases first before run
 
Quote:

Originally Posted by glik (Post 660926)
Which condition did you use for the top ?
And with a thinner mesh it should be better ;)

Quote:

Originally Posted by camposrf (Post 660117)
(...)it is a coarsed one. I have to do approximation cases first before run a detailed model “if I want the results this year” (joke):). Further more, it has a worst residuals convergence (0.01). The good news is that the time step is ok because it is a steady simulation.
I have to do this previous work because I do not have a powerful PC. I accept donations (is not a joke).

For the top I used opening as boundary condition at 0 KPa.

Yes, with a thinner mesh it will be better; I will use the refined one when I get some reliable results.

My priority is get rid of the common errors first. At the beginning I do a steady simulation, then the transient, and finish with the refined mesh.

camposrf August 17, 2017 09:25

Sloshing tutorial
 
I found these tutorial, maybe it could help you.

https://www.youtube.com/watch?v=oIFfPEWHkxw

https://www.youtube.com/watch?v=SwSbXwIKoto


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