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

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?


Attachment 95378

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

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

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.

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.

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?

Hi I've forwarded it to you via PM.

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

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.