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japanese student November 4, 2014 07:36

Pressure contour
 
2 Attachment(s)
Hello!
If you answer my questions, I appreciate your advices!

I study about the fluid dynamics in a bubble column.
The bubble dissolve into the liquid.

In CFD-POST, I got bad results of pressure contours(fig1).
In fig1, bubble(co2) dissolved.
I want to get like this(fig2).
In fig2, bubble(air) didn't resolve.

Why did I get that result?
I get that reslut when I study about the bubble which dissolves into liquid.
And which pressure contours do I have to use?

Thank you!

japanese student November 5, 2014 22:58

Please help my question.

japanese student November 12, 2014 22:54

detail settings
 
I couldn't get any advices of the Pressure contoure, so I give you detail settings.
If you give me some advices, I express my thanks!

The system:The bubble which dissolves in the liquid rises in the bubble column(2D).

The settings:
General; transient, gravity -9.8
Models; vof (Explicit), species transfer
Materials; water, co2
Phases; phase-1(mixture), phase-2(mixture)
Interactions; phase-1(co2)to phase-2(water) mass=5(kg/m3・s)
Boundary; inlet(0.14m/s), outflow
Solution method; NITA
time step; 5e-5

When the mass is much less(0.001kg/m3・s ect ....), the pressure contour is good.
Why is the pressure contour is bad, when the mass is big?


Thank you!

japanese student December 27, 2014 11:30

Hello,everyone!

I probably got the reason the pressure contour is strange.
I assume the fluid is the incompressible fluid, but the density has changed after the mass transfer across the liquid-gas interface occered.

So, I want to get how to make the density constant.

If you tell me some advices, I am very happy.

Thanks!


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