Do I need to use UDF to define source term in governing equations?

- May 18, 2019 at 3:18 pm
  
  Weiqiang Liu
  Subscriber
  
  Hi all,
  
  I am doing a soot combustion simulation with fluent. The local soot mass concentration is defined as an UDS. There are source terms in continuity and enthalpy equations due to soot oxidation. In the literature I am referencing, the author mentioned all the source terms are defined by UDF. However, according to my modeling experience, I just need to define reaction first and then assign this reaction to particular cell zones.
  
  Do I really need to define source terms additionally with UDF in this case?
  
  I put the geometry of this case below:
  
  Soot combustion happens in the cake and porous wall region.
  
  Best.
  
  Weiqiang
- May 20, 2019 at 4:39 am
  
  DrAmine
  Ansys Employee
  
  If it is soot defined by YES2not the soot model in Fluent you will require Source terms either by UDF or via Expressions
- May 20, 2019 at 2:00 pm
  
  Weiqiang Liu
  Subscriber
  
  Yes, it's soot defined by myself. Thanks very much
  
  Best.
  
  Weiqiang