Counter-current multiphase flow

Borsche · May 29, 2014, 18:06

I have found multiple threads asking this same question, with no answer given in any of them.

Does anyone know how to set up the boundary conditions for counter current multiphase flow? Where the inlet for one phase is the outlet for the other?

I am using the Eulerian model for multiphase flow. Essentially the system is a tube where solids enter from the top and gas from the bottom. Any help would be appreciated.
Thanks

coolgame2004 · October 4, 2014, 03:43

have you figured out it yet? I meet the same problem.

Quote:

Originally Posted by Borsche

I have found multiple threads asking this same question, with no answer given in any of them.

Does anyone know how to set up the boundary conditions for counter current multiphase flow? Where the inlet for one phase is the outlet for the other?

I am using the Eulerian model for multiphase flow. Essentially the system is a tube where solids enter from the top and gas from the bottom. Any help would be appreciated.
Thanks

Borsche · October 4, 2014, 14:28

No, I haven't! I have paused working on the problem. A colleague of mine is working on the same type of problem, and is using DEM for this purpose, but I would like do use the Euler-Euler approach.

CeesH · October 8, 2014, 23:31

I wouldn't mind helping, but with your current description, I don't see what the problem is. Set a velocity inlet for dispersed phase near the top, one for continuous phase near the bottom, and at least one pressure outlet somewhere.

Borsche · October 9, 2014, 00:56

The problem that we are having, is that we are unable to set one face to be the inlet of the dispersed phase and the outlet of the continuous phase. I cannot set the pressure outlet of one phase in the same face as the inlet of another.

CeesH · October 9, 2014, 01:10

Ok, so the geometry you are using is some kind of open-ended tube, in which it would be wrong to seperate the in- and outlet? I agree, that is a difficult problem, and I am not aware of any off-the-shelve solution for that. My suggestion would be to dive into user defined functions on this one, but I'm not completely sure as I have no experience with this type of geometry. You don't see any option to segregate in and outlet as with a spray dryer or so?

coolgame2004 · October 9, 2014, 08:22

I am trying to use the UDF to solve this problem. I found that the macro F_C0(cell,thread) might be helpful for solving this problem (my idea is that: at the inlet of the continuous phase, i.e. at the bottom gas inlet boundary, i hook a inlet solid boundary using DEFINE_PROFILE, which extracts the values of the cell nearby this boundary. those value includes the velocity, volume fraction etc of the solid). but to hook this macro F_C0(cell,thread), i need to compile the UDF rather than interpret it. now i have a problem to compile the UDF (i have been using the interpreted UDF before). these two days i try every best but failed~ the error is like this:
Error: open_udf_library: The system cannot find the file specified.
help me~

Quote:

Originally Posted by Borsche

The problem that we are having, is that we are unable to set one face to be the inlet of the dispersed phase and the outlet of the continuous phase. I cannot set the pressure outlet of one phase in the same face as the inlet of another.

coolgame2004 · October 9, 2014, 08:30

Thanks for you advice!
these days i do try to use the UDF to solve this problem. my idea is to use the F_C0(cell,thread) macro, but i haven't obtained useful results. i will get on with it.

Quote:

Originally Posted by CeesH

Ok, so the geometry you are using is some kind of open-ended tube, in which it would be wrong to seperate the in- and outlet? I agree, that is a difficult problem, and I am not aware of any off-the-shelve solution for that. My suggestion would be to dive into user defined functions on this one, but I'm not completely sure as I have no experience with this type of geometry. You don't see any option to segregate in and outlet as with a spray dryer or so?

rudofly · November 11, 2014, 09:36

Hi!

How is your progress on UDFs? I wonder why solids need to be able to exit the domain? What you want to simulate sounds a lot like a fluidized bed to me.

Best regards,

Rudi

coolgame2004 · August 31, 2015, 02:26

Quote:

Originally Posted by rudofly

Hi!

How is your progress on UDFs? I wonder why solids need to be able to exit the domain? What you want to simulate sounds a lot like a fluidized bed to me.

Best regards,

Rudi

Hi~
I 'am still get on with it.
you are right, the purpose of using such (inlet+outlet) boundary conditions is to model a gas-solid countercurrent FB.

Sincerely,
Richard

abc197 · December 6, 2015, 06:16

Hi guys,

Have you been able to figure this out? I have been working on the same problem. How about this approach- At the inlet of continuous phase, using mass flow rate of dispersed phase in -ve direction. This way, both phases are in opposite directions. Temperature values can be mentioned at continuous phase outlet, which is also the inlet for dispersed phase. Can this work? I would really welcome any other approach that might have worked in this problem.

May 29, 2014, 18:06	Counter-current multiphase flow	#1
Borsche New Member Boris Join Date: May 2014 Posts: 7 Rep Power: 12	I have found multiple threads asking this same question, with no answer given in any of them. Does anyone know how to set up the boundary conditions for counter current multiphase flow? Where the inlet for one phase is the outlet for the other? I am using the Eulerian model for multiphase flow. Essentially the system is a tube where solids enter from the top and gas from the bottom. Any help would be appreciated. Thanks

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October 4, 2014, 14:28		#3
Borsche New Member Boris Join Date: May 2014 Posts: 7 Rep Power: 12	No, I haven't! I have paused working on the problem. A colleague of mine is working on the same type of problem, and is using DEM for this purpose, but I would like do use the Euler-Euler approach.

October 8, 2014, 23:31		#4
CeesH Senior Member Cees Haringa Join Date: May 2013 Location: Delft Posts: 607 Rep Power: 0	I wouldn't mind helping, but with your current description, I don't see what the problem is. Set a velocity inlet for dispersed phase near the top, one for continuous phase near the bottom, and at least one pressure outlet somewhere.

October 9, 2014, 00:56		#5
Borsche New Member Boris Join Date: May 2014 Posts: 7 Rep Power: 12	The problem that we are having, is that we are unable to set one face to be the inlet of the dispersed phase and the outlet of the continuous phase. I cannot set the pressure outlet of one phase in the same face as the inlet of another.

October 9, 2014, 01:10		#6
CeesH Senior Member Cees Haringa Join Date: May 2013 Location: Delft Posts: 607 Rep Power: 0	Ok, so the geometry you are using is some kind of open-ended tube, in which it would be wrong to seperate the in- and outlet? I agree, that is a difficult problem, and I am not aware of any off-the-shelve solution for that. My suggestion would be to dive into user defined functions on this one, but I'm not completely sure as I have no experience with this type of geometry. You don't see any option to segregate in and outlet as with a spray dryer or so?

November 11, 2014, 09:36		#9
rudofly New Member Rudi Join Date: Jun 2014 Posts: 14 Rep Power: 12	Hi! How is your progress on UDFs? I wonder why solids need to be able to exit the domain? What you want to simulate sounds a lot like a fluidized bed to me. Best regards, Rudi

December 6, 2015, 06:16		#11
abc197 Member Ravi Agrawal Join Date: Dec 2012 Posts: 40 Rep Power: 13	Hi guys, Have you been able to figure this out? I have been working on the same problem. How about this approach- At the inlet of continuous phase, using mass flow rate of dispersed phase in -ve direction. This way, both phases are in opposite directions. Temperature values can be mentioned at continuous phase outlet, which is also the inlet for dispersed phase. Can this work? I would really welcome any other approach that might have worked in this problem.