Modelling Stirred Tank Reactor Agitated By Magnetic Rod Stirrer (No Baffles)

sr786 · July 14, 2023, 09:19

Hi,

I am looking to use OpenFOAM to model an unbaffled stirred tank reactor agitated by a magnetic rod stirrer (located as base of reactor) as shown in image. The system will consist of air-water, where the interface between the two phases will deform inducing a vortex. I've simulated this case before in ANSYS FLUENT.

As the case is quite complex (including rotating stirrer, multi-phase flow, etc) I need advice on how to go about setting up this case (i.e., a workflow).

I know I want to use a single reference frame (SRF) model for the rotation, and Volume of Fluid (VOF) to track free surface deformation.

Also, what advice would you give in regards to meshing tool. I know OpenFOAM has an inbuilt mesher (snappy hexmesh) which can produce hexes. How easy will it be to implement hexes for my geometry as previously I've used a tet mesh using ANSYS Mesher?

Geometry.png

alfa_8C · August 21, 2023, 02:52

Hi,
Have you solved this already? I have extensive experience with this and could guide you including OpenFOAM and snappy.

sr786 · August 21, 2023, 03:26

Hi,

I’ve managed to set up a single phase run (tank filled with water) using single reference frame to model stirrer rotation.

I haven’t used Snappyhexmesh but instead used Salome to generate an unstructured mesh. So far simulation results look okay, not progressed to multi-phase solver yet

alfa_8C · August 21, 2023, 05:41

I am not sure if simpleSRFFoam have coriolis forces implemented. I'd recommend to use MRF instead. Corresponding tutorials can be found.

MRF solvers are created at runtime and can be used for multi-phase too. I don't think this is possible for simpleSRFFoam.

sr786 · August 21, 2023, 11:25

Hi,

No worries and thank you for the advice. How would I implement a SRF using MRF in OpenFOAM.

I only have one cell zone defined which includes all the cells in the computational domain.

alfa_8C · August 26, 2023, 09:38

Hi, I can provide a sample case, but I cannot share a link here. Can you please provide an email address where to share the link to?

sr786 · August 26, 2023, 10:51

Hi I've forwarded it to you via PM.

Ruonin · April 10, 2024, 06:57

Hi,

hijacking a bit this thread to prevent creating duplicates.

I'm also interested in this kind of simulation for magnetic bar stirrers.

Were you successful in your simulation? Also, did you tracked/calculated the torque?

Best,
R

alfa_8C · April 10, 2024, 08:40

Hi,

I do these simulations with OpenFOAM and generally speaking these kind of simulations are pretty standard, in particular with MRF. So running them successfully shouldn't be e big deal.
In OpenFOAM, torque can be written out by the forces and moments function in the controlDict.

July 14, 2023, 09:19	Modelling Stirred Tank Reactor Agitated By Magnetic Rod Stirrer (No Baffles)	#1
sr786 Member sr786 Join Date: Jan 2023 Location: Leeds, UK Posts: 50 Rep Power: 3	Hi, I am looking to use OpenFOAM to model an unbaffled stirred tank reactor agitated by a magnetic rod stirrer (located as base of reactor) as shown in image. The system will consist of air-water, where the interface between the two phases will deform inducing a vortex. I've simulated this case before in ANSYS FLUENT. As the case is quite complex (including rotating stirrer, multi-phase flow, etc) I need advice on how to go about setting up this case (i.e., a workflow). I know I want to use a single reference frame (SRF) model for the rotation, and Volume of Fluid (VOF) to track free surface deformation. Also, what advice would you give in regards to meshing tool. I know OpenFOAM has an inbuilt mesher (snappy hexmesh) which can produce hexes. How easy will it be to implement hexes for my geometry as previously I've used a tet mesh using ANSYS Mesher? Geometry.png

August 21, 2023, 11:25		#5
sr786 Member sr786 Join Date: Jan 2023 Location: Leeds, UK Posts: 50 Rep Power: 3	Hi, No worries and thank you for the advice. How would I implement a SRF using MRF in OpenFOAM. I only have one cell zone defined which includes all the cells in the computational domain. Last edited by sr786; August 21, 2023 at 17:04.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Issue with implementing kOmegaSST model in steady state stirred tank simulation	WJPeace1	OpenFOAM Running, Solving & CFD	0	July 12, 2023 12:44
Modelling stirred tank reactors	Nishant	FLUENT	4	January 24, 2011 12:45
Stirred Tank Reactor Modelling	alice	FLUENT	2	January 23, 2011 14:59
sliding mesh for stirred tank modelling	Gopal Kasat	FLUENT	0	June 24, 2005 05:38
CFX 5.5.1 stirred tank and LES problem	Nishant	CFX	2	September 13, 2002 07:11

August 21, 2023, 02:52		#2
alfa_8C Member Antonio Liggieri Join Date: Aug 2010 Posts: 76 Rep Power: 14	Hi, Have you solved this already? I have extensive experience with this and could guide you including OpenFOAM and snappy.

August 21, 2023, 03:26		#3
sr786 Member sr786 Join Date: Jan 2023 Location: Leeds, UK Posts: 50 Rep Power: 3	Hi, I’ve managed to set up a single phase run (tank filled with water) using single reference frame to model stirrer rotation. I haven’t used Snappyhexmesh but instead used Salome to generate an unstructured mesh. So far simulation results look okay, not progressed to multi-phase solver yet

August 21, 2023, 05:41		#4
alfa_8C Member Antonio Liggieri Join Date: Aug 2010 Posts: 76 Rep Power: 14	I am not sure if simpleSRFFoam have coriolis forces implemented. I'd recommend to use MRF instead. Corresponding tutorials can be found. MRF solvers are created at runtime and can be used for multi-phase too. I don't think this is possible for simpleSRFFoam.

August 26, 2023, 09:38		#6
alfa_8C Member Antonio Liggieri Join Date: Aug 2010 Posts: 76 Rep Power: 14	Hi, I can provide a sample case, but I cannot share a link here. Can you please provide an email address where to share the link to?

August 26, 2023, 10:51		#7
sr786 Member sr786 Join Date: Jan 2023 Location: Leeds, UK Posts: 50 Rep Power: 3	Hi I've forwarded it to you via PM.

April 10, 2024, 06:57		#8
Ruonin Member Join Date: Apr 2011 Posts: 56 Rep Power: 15	Hi, hijacking a bit this thread to prevent creating duplicates. I'm also interested in this kind of simulation for magnetic bar stirrers. Were you successful in your simulation? Also, did you tracked/calculated the torque? Best, R

April 10, 2024, 08:40		#9
alfa_8C Member Antonio Liggieri Join Date: Aug 2010 Posts: 76 Rep Power: 14	Hi, I do these simulations with OpenFOAM and generally speaking these kind of simulations are pretty standard, in particular with MRF. So running them successfully shouldn't be e big deal. In OpenFOAM, torque can be written out by the forces and moments function in the controlDict.