Implementation of coupled boundary condition for UDS in Fluent

- March 9, 2020 at 2:38 pm
  
  MarkusP
  Subscriber
  
  Dear community members,
  
  I am currently simulating a transient fluid-solid problem where a UDS transport equation needs to be solved in both fluid and solid zones. Fluent offers the boundary condition option "Coupled" for the boundary between fluid and solid zones.
  
  Does anyone know how this coupled boundary condition for UDS is implemented in Fluent, i.e. which equation(s) is (are) applied?
  
  Many thanks in advance!
  
  Best regards,
  Markus
- March 9, 2020 at 4:09 pm
  
  DrAmine
  Ansys Employee
  
  Same way as for temperature scalar property solved in two adjacent fluid solid zones. The value has to be the same at the boundary.
- March 9, 2020 at 4:26 pm
  
  MarkusP
  Subscriber
  
  Thanks, Amine.
  
  What about the boundary fluxes (heat or UDS)? Don't they also have to be the same on both sides of the boundary (for conservation reasons)?
  
  I did not find the equations for the coupled boundary condition (UDS) anywhere in the documentation. Can I find these equations anywhere else?
  
  Best regards,
  Markus
- March 10, 2020 at 5:51 am
  
  DrAmine
  Ansys Employee
  
  No you cannot find it elsewhere. Yes as for the temperature the heat flux on one side will correspond to the other side. So what ever is true for temperature is true for any other scalar