Hi
I built a model using Eulerian two-phase model with Population Balance Model in Fluent.
A cylindrical tank with the height 2 m and the diameter 1 m contained 80% water inside.
The pressure outlet was at top. Only air is allowed to flow back and no bin using PBM discrete method could flow back.
Initially, gas zone and water zone were patched 1 and 0 fraction of air, separately.
The air velocity inlet with a diameter 1 cm was located at the bottom.
The supersonic/initial gauge pressure was set 12000 Pa, and the reference pressure location of the operating pressure located at the top.
The air is set as a compressible ideal gas. The air velocity is 1 m/s.
I have three question:
1. Is it right to set the supersonic/initial gauge pressure as 12000 Pa ?
2. Is it right to set no bin flow back?
3. How to make the bubbles dissipate? It seems the bubbles never dissipate even they pass through the interface of air and water.
Could someone help, please?
Hi,
1. Is it right to set the supersonic/initial gauge pressure as 12000 Pa ?
Why??? If you have the air velocity or mass flow rate, an approximation of 0 Pa would work fine.
3. How to make the bubbles dissipate? It seems the bubbles never dissipate even they pass through the interface of air and water.
I had a similar problem with the ANSYS CFX, I decided to work on the boundary condition of the output.
In your case with Fluent, check this, especially as related to the air Backflow Volume Fraction.
I think I have some tutorials about this if you are interested.
Greetings
Thanks for your response!
>1. Is it right to set the supersonic/initial gauge pressure as 12000 Pa ?
>Why??? If you have the air velocity or mass flow rate, an approximation of 0 Pa >would work fine.
OK~ I'll set as 0 Pa.
>3. How to make the bubbles dissipate? It seems the bubbles never dissipate >even they pass through the interface of air and water.
>I had a similar problem with the ANSYS CFX, I decided to work on the boundary >condition of the output.
>In your case with Fluent, check this, especially as related to the air Backflow >Volume Fraction.
>I think I have some tutorials about this if you are interested.
>Greetings
Thank you! Some tutorials will be very helpful!
I am very interested!
Would you please attach them using File or Link buttons when replying or any other way?
Thank you so much!
I will try them. I found they are used for an incompressible flow.
I had tried PBM with an incompressible flow, and it soon diverged.
Then I had tried IAC with an incompressible flow, and it also soon diverged.
I used to get divergence as well. After I set the recommended Under Relaxation Factors, it all works fine. I'm using ANSYS-FLUENT v15.0.
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