How to impose a mass flowrate or pressure drop without boundaires

- September 22, 2023 at 12:51 pm
  
  AnthonyB08
  Subscriber
  
  Hi all,
  
  How can I impose a pressure drop or mass flowrate for my following fluid domain? Would I use a profile UDF?
  
  I am trying to simulate a representative elementary unit of a packing element.
  A gas will flow upward by induced flow rate or pressure drop. The faces on the top, bottom, right, and left are periodic while the front and back are wall conditions.
  
  -Thanks
- September 22, 2023 at 2:53 pm
  
  Rob
  Forum Moderator
  
  I don't think you can use periodic as there aren't one pair of "ends" to the section. Similarly periodic & symmetry doesn't look practical. You may need to model a slightly larger section and use symmetry planes to the sides.
  Gas going up, are you planning on liquid going down?
- September 22, 2023 at 2:55 pm
  
  AnthonyB08
  Subscriber
  
  Many sources use this method in ansys for REU. No single phase. Is a pressure drop implementation just a source term?
- September 22, 2023 at 3:04 pm
  
  Rob
  Forum Moderator
  
  Pressure drop would be boundary conditions. You can use porous media or source terms on the cell zones, but I don't think that's what you want here.
- September 22, 2023 at 3:06 pm
  
  AnthonyB08
  Subscriber
  
  CFD-based study on structured packing geometry - ScienceDirect
  
  This was done in ANSYS with 4 periodic boundary conditions and a pressure gradient applied in the z -direction.