Learning Forum

[cheza8]

Hi everyone, 

I am doing research for my master degree thesis. I am trying to create a gas liquid cyclone separator (the gas should be air and the liquids water and oil) with a tangential inlet.  I am trying to include ANSYS simulations of the vortex within the cyclone model.

I have drawn my cyclone model on spaceclaim and imported it onto ANSYS, I am looking for guidance for what parameters I should set along with boundary conditions.

I have tried to follow some tutorials here on the forum and on youtube, but most of them are about separation of solid particles from the main flow, none of them is about separation of gasses and liquids.

I am just a beginner, so I could really use some help.

Usually these are the steps I follow:

1) steady simulation, with gravity

2)In the model I set Multiphase ( air and water.. I'll try to add the oil later when all will begin to work) and Turbulent (k epsilon - RNG- Swirl dominated flow). 

3) In physics I set all the phases

4)Materials: air and water liquid

5)Boundary conditions: the inlet is a velocity inlet ( the phases are 0.5 air and 0.5 water, but I am not sure I'm doing this correctly) and liquid and gas outlets are pressure outlets ( again, I am not sure I am doing this correctly)

6)For solution methods I select second order equations

7) I do not perform an hybrid initialization

When I tried to perform transient simulations I had a lot of troubles with selecting the correct Timesteps for having the Courant Number smaller than one, but even in that case I didn't get a plausible solution; with steady simulation, again, I don't know exactly what I am doing so I can really use some help.

 

Hoping that someone could give me some advises, thank you!

 

[Karthik Remella]

Hello,

Can you please take a look at this tutorial and see if this helps you answer some of your questions?

https://www.youtube.com/watch?v=RO5IGUvgNoU

Thanks,

Karthik

[cheza8]

Hi, thanks for answering!

This was the first tutorial I followed, but , even if the Courant Number is smaller than 1, the residuals seem to never converge . By the way I didn't set the swirl dominated flow yet(following this tutorial I didn't think about it). I could try.

Now I am following this tutorial of Raeff Kobeissi, adapting it to my needs:

https://www.youtube.com/watch?v=LSoQDmz9tyM&list=LLBGaxoWSNtq1RF_bJru956A&index=2&t=0s

And these are the contours of air and water I get, but I don't know if they are physically acceptable:

[Karthik Remella]

Hello,

You say you are modifying the tutorial to suit your needs - have you followed the exact tutorial just to see if you are able to first replicate the results from the video? If so, what modifications have you made to your simulation?

Best,

Karthik

[cheza8]

Hi, 

I followed the exact tutorial of Raef Korbessi (the one I posted), with only two differences:

1st) For materials he sets air and sand, while I set air and water liquid

2nd) Among the models he sets also the Discrete phase, in order to model the sand particles. I thought that gas and liquid should be continous phases so I didn't set this model

 

In the end, in the boundary conditions I set the same inlet for gas and liquid (velocity inlet) and the same input velocity (0.15 m/s), while the outlets are both pressure outlets.

I didn't try the modeling with air and sand, because I don't need it.

 

[acvasc]

Hello Cheza8,

Were you able to model your separator? I am working on something very similar. Would you like to discuss about it?

best regards.

[chand101]

Hi. 

I am trying to model separation of a gas phase (air phase to be separated) from another gas phase(water vapor). I want to also include condensation of water vapor into liquid phase and dont want to include this in seperation . Is fluent capable of doing this? Please guide me on the correct multiphase model to choose

[geetdeokate]

hello can you please send me the tutorial you followed to do the separation analysis, I am also working on something similar, the video you have uploaded up has gone in private and hence I cannot have access to it. 

Thank you

[geetdeokate]

hello , I am working on simulation of vapor liquid separator, If you have completed your simulation could you please help me with a video of the process so that I can also simulate, Its my Masters project.

 

Thank you

[geetdeokate]

Hello Could you please upload the video again, it has gone in private.

Thank you

[Alexis OB]

Hello everyone, i hope you are all doing well. Could anyone guide me with the geometry ? I'm very new to this and i don't know how to get started; i've watched tons of tutorial videos on youtube and they aren't really helpful. 

[Alexis OB]

Hello everyone, i hope you are all doing well. Could anyone guide me with the geometry ? I'm very new to this and i don't know how to get started; i've watched tons of tutorial videos on youtube and they aren't really helpful. Thank you

[Laura Osorio Ojeda]

Hello, could you share your thesis with me?

[Rob]

It's quite an old thread and not all of the content will still be available. You may be better off starting a new thread, but I'll leave this open incase any of the previous posters are active.