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How to use custom viscosity models as UDF

    • allenpvar
      Subscriber

      Hey,


      I am attempting to understand how to use UDF's in PolyFlow. According to the manual, UDF can be used to define value parameters (for material data) or boundary conditions.


      These can be functions of the following quantities:



      • Fields: such as the velocity, the temperature, or the pressure

      • Additional quantities: local compression rate, local shear rate, local stretch rate etc.

      • Evolution parameter S (EVOL-based functions)


      The manual also mentions that we can use the parameters listed in the Additional quantities to derive generalized Newtonian viscosity models as seen in the screenshot below,



      How do I use these custom generalized Newtonian viscosity model in Polyflow? 


      The manual only explains how to use the PMAT button in Polyflow to define a UDF within a field inside an existing shear rate dependence viscosity model or temperature dependence viscosity model



      I am using Polyflow within Ansys workbench, so I have read that you need to save it as a UDF file and import it by right clicking Setup and importing it. Next you have to enable it for use by right clicking Solution > Preferences > Polyflow and click the the Use a UDF checkbox.


      I must be doing something wrong, can you please advice, how I can use a custom generalized Newtonian viscosity model ?


      Thank you

    • Benjamin Ducoeur
      Ansys Employee

      Hi,


      Please look in the help : https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/prod_page.html?pn=Polyflow&lang=en


      In the section "Polyflow Examples Files", you will find example 12.   It is an example about UDF applied to a viscosity law.


      Hope this helps.

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