UDF : Modified DES

- March 12, 2021 at 12:53 pm
  
  Bibill
  Subscriber
  
  Dear all,nI would like to modify the distance function causes the model to behave as RANS in a Detached Eddy Simulation. Is there a possibility to impose our own distance function by means of a UDF ?.Thanks in advance !n
- March 12, 2021 at 12:58 pm
  
  Aitor
  Subscriber
  
  Unfortunately, it is not possible. Why do you want to modify the distance function?n
- March 12, 2021 at 1:04 pm
  
  Bibill
  Subscriber
  
  Thank you Aitor for your answer !I'd like to solve with LES only in a part of the fluid domain, defined by an in-house criterion, and with RANS otherwise.n
- March 12, 2021 at 1:17 pm
  
  Aitor
  Subscriber
  
  In that case, I recommend you to use SBES modeln4.14. Stress-Blended Eddy Simulation (SBES) (ansys.com)nThis is essentially an improvement of the DES model, and you can modify the blending function by means of User-Defined Functions (UDF).nIf the RANS - LES interface is known and the geometry is simple, Embedded Large Eddy Simulations (ELES) are also a good choice.n4.16. Embedded Large Eddy Simulation (ELES) (ansys.com)n
- March 12, 2021 at 1:23 pm
  
  YasserSelima
  Subscriber
  
  search the udf manual for define_trans_flength macron
- March 12, 2021 at 4:50 pm
  
  Bibill
  Subscriber
  
  Thank you very much !! These are the pieces of answer I was looking for !n
- March 13, 2021 at 11:58 am
  
  YasserSelima
  Subscriber
  
  You are welcome! Good Luck!n

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