What does it mean by ‘Warning: zone of type interior found between different solids!’?

- January 2, 2019 at 12:34 pm
  
  Donghyun Yim
  Subscriber
  
  Hi,
  
  When I initialize the solution on fluent solve, the following message appears.
  
  Warning: zone of type interior found between different solids!
  
  Material of cell zone 14 is sus, while material of cell zone 13 is polymide.
  
  This will adversely affect the solution.
  
  It is recommended that you fix this issue via the TUI command
  
  /mesh/modify-zones/slit-interior-between-diff-solids
  
  Unless I enter the above command it diverges, but when I enter that command it converges.
  
  I got the final solution, but I am curious of why that warning appeared.
  
  Thanks,
  
  Donghyun
- January 2, 2019 at 12:49 pm
  
  Keyur Kanade
  Ansys Employee
  
  'interior' is nothing but the interior cells. for any boundary usually we have 'wall' type. so it it is 'interior' then solver will treat as 'interior' rather than 'wall'.
  
  if this helps you, please mark this post as 'is solution' to help others on forum.
- January 2, 2019 at 1:00 pm
  
  Donghyun Yim
  Subscriber
  
  So that warning message implies the absence of wall between different interiors (or solids), and that command splits them.
  
  If so, do I need to modify mesh before solve in order to prevent that warning?
  
  Thanks,
  
  Donghyun
- January 2, 2019 at 1:19 pm
  
  Keyur Kanade
  Ansys Employee
  
  no need to modify mesh.
  
  select face between two solids in meshing and give named selection.
  
  if you already have different named selection for this then please select this named selection in fluent and change its type to wall.
  
  https://www.youtube.com/watch?v=-6Z2v8geroQ
- January 2, 2019 at 1:53 pm
  
  Donghyun Yim
  Subscriber
  
  If the type of face between two faces is set to be wall, no thermal energy exchange or uds exchange occurs across the wall. (as I understood)
  
  So its type needs to be 'interface', not 'wall', doesn't it?
  
  Thank for your kind reply,
  
  Donghyun
- January 3, 2019 at 3:58 am
  
  Keyur Kanade
  Ansys Employee
  
  you can set it as interface depending your configuration.
- November 30, 2023 at 11:05 am
  
  Ayushman Srivastava
  Subscriber
  
  warning: zone of type interior found between different fluids!
  Material of cell zone 8 is helium, while material of cell zone 9 is air.
  This will adversely affect the solution.
- November 30, 2023 at 11:56 am
  
  Rob
  Forum Moderator
  
  Yes, that's a problem.
- November 30, 2023 at 2:58 pm
  
  Ayushman Srivastava
  Subscriber
  
  Please tell me how to resolve this problem.. i am facing the problem of floating point exception. Residual curves git diverged ... Please help me resolve this problem
- November 30, 2023 at 3:43 pm
  
  Rob
  Forum Moderator
  
  You have helium & air in connected fluid zones. That's not permitted without using some additional models. So, why have you got helium & air in connected fluid zones?
- November 30, 2023 at 5:30 pm
  
  Ayushman Srivastava
  Subscriber
  
  I have a shock tube. driver section of the shock tube is filled with helium at 0.9 MPa and the driven section is filled with air at atmospheric pressure. the diaphragm is there which separates the driver and driven section with each other. diaphragm ruptures and helium and air mixes with each other. shock wave then generates. How to remove that warning message and how to stop residual curves from diverging?
- December 1, 2023 at 9:42 am
  
  Rob
  Forum Moderator
  
  You'll need a species model, the tube is then a mixture of helium & air. To initialise the system you patch air & helium into the respective regions. Have a look at the species models tutorials in Help.
- December 1, 2023 at 1:06 pm
  
  Ayushman Srivastava
  Subscriber
  
  I patched the driver , driven sections in the cell zone condition. I was compelled to choose a mixture_template (helium+air) for the driver and driven section to avoid any warning or error. Simulation was running smoothly. Is it right way to run the simulation? As i wanted only helium in the driver section and air in the driven section, I dont know whether it is right to select the mixture_template.
  But when i selected helium in the driver section and air in the driven section after turning ON the species transport model, a warning and error appeared. residuals were diverging.
- December 1, 2023 at 1:17 pm
  
  Rob
  Forum Moderator
  
  Divergence is a different issue, and mostly likely linked to the mesh or solver settings.
  As you have two materials mixing you must use the species model. The cell zone contains the "mixture-template" and when you initialise you then need to patch species to suit.
- December 1, 2023 at 1:21 pm
  
  Ayushman Srivastava
  Subscriber
  
  my question is "After initializing, how to patch the driver with helium and the driven section with air after turning ON species transport model?"
- December 1, 2023 at 2:20 pm
  
  Rob
  Forum Moderator
  
  After you initialise, you should see a button with "Patch" on it.