Fluids

Fluids

Define_profile is not working for surface_volume ratio for porous media

    • pavankonchada123
      Subscriber

      I am trying to use below udf for surfacearea_volume in ansys fluent for porous media in reactions but Iam not able to see any udf in drop down

      DEFINE_PROFILE(Surface_area_Volume_ratio,t,i)
      {
      #if !RP_HOST  
       cell_t c;
        real x[ND_ND];
        real void_fraction,solid_volume;
        begin_c_loop(c,t)
          {
              if(C_DPMS_CONCENTRATION(c,t)>0)
              {
              solid_volume = C_DPMS_CONCENTRATION(c,t)/2300;
            void_fraction = (1-solid_volume)/solid_volume;
            F_PROFILE(c,t,i) = M_PI*pow((6*C_VOLUME(c,t)*void_fraction/M_PI),0.66666)/C_VOLUME(c,t);
              }
            else
               F_PROFILE(c,t,i) =0;  
              }
          
        end_c_loop(c,t)
         #endif    
      }

    • pavankonchada123
      Subscriber

      And also tried to use expression but it is saying expression is not single valued

      void_fraction1 :

      (1 - (DPMConcentration*1[m^3/kg] / 2300)) / (DPMConcentration*1[m^3/kg] / 2300)

      surface_volume:

      3.14*1[m^-1] / (CellVolume*1[m^-3]) * (6 * CellVolume*1[m^-3]*void_fraction1 / 3.14) ^ 0.666

    • DrAmine
      Ansys Employee

      What do you want to modifiy? Probably it requires a single valued expression and not a field.

    • pavankonchada123
      Subscriber

      Surface to volume ratio for reaction in porous media.

      Can you let me know which macro should I use define profile is not working

    • DrAmine
      Ansys Employee

      That input cannot be provided via a profile it requires a single valued input. 

    • pavankonchada123
      Subscriber

      But my value depends on void fraction on each cell of domain. Is there any way I can define different values on different cells with voidfraction as variable

    • DrAmine
      Ansys Employee

       

      Built-in capability: I need to say no. You require more efforts to do that. For that reason, I think we should enhance this and allows the value to be a field input. I will discuss this with my colleagues.

       

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