2 Way CFD DEM Coupling

- December 22, 2023 at 1:11 pm
  Ani94
  Subscriber
  Hello Everyone,
  
  I am trying to simulate 2 way coupling of Fluent-Rocky DEM using Workbench. I am facing few issues while performing simulation.
  1. I first created a case setup in fluent and initialized it and saved it as .cas file.
  2. Later in Rocky window i dragged and dropped fluent setup to Rocky setup, linking them using 'unresolved 2 way coupling' option.
  3. I uploaded the geometry in rocky geometry.
  4. Created particles, setup boundary conditions.
  5. After solver setup, I started simulation, which opened the fluent and both fluent and Rocky started solving simultaneously.
  6. After calculation was complete, when I tried post processing it i was able to see simulation of particles in the domain.
  Issue 1: But then why workbench is still not showing the calculation as complete. Workbench workflow is as shown below:
  Issue 2:
  While I was going through the documentation of Rocky DEM, It mentioned as highlighted in below image:
  1.     Where I can upload the .dat file in rocky?
  2.     Is this related to the issue I am facing?
  3.     Whatever procedure I am following is okay?
  I would like to know, how can I resolve both the issues? Any help regarding this will be appreciated. Thanks !!!
- December 22, 2023 at 2:09 pm
  
  Rob
  Forum Moderator
  
  There should be some more tutorials/help/training coming with/soon after 2024R1 which will help.
  The approach I always take is to set up & run as much of the Fluent model as I want and then use the case file as the starting point in Rocky: neither code is used inside Workbench. When you set up the coupling from Rocky there are options to link the case file and load an initial data set.
  Note, particles that are big relative to the CFD geometry and mesh may cause some stability problems. There's an option to help with this, but I can't remember what it is.
- December 27, 2023 at 11:03 am
  
  Ani94
  Subscriber
  
  Hey Rob,
  Thank you so much for replying.
  The approach of solving the fluent first as much as we need followed by linking it to Rocky and solving it will be used in One way Coupling right?
  In my case I am trying to simulate particle drying in which both will have to exchange and solve simultaneously. Thats where i am encountering the issue as fluent solution window is not showing any result even after completing calculations.
- January 2, 2024 at 11:56 am
  
  Rob
  Forum Moderator
  
  OK, particle drying may be a little more complex as I can't remember how Rocky handles that. If you're looking at a bulk flow with little particle load, then you can set the Fluent model up with all the parts that Rocky needs and then run it without coupling to get the initial data set. Then set up Rocky (standalone) and attach Fluent via the coupling along with the initial data file. If the system is tightly coupled then the Fluent data you load into Rocky would be the initialised condition.