Fluids

Fluids

In order to include uds properly

    • Austin_p
      Subscriber

      I 'm trying to use UDS which is written in the ansys fluent guide 2.7.3

      /**********************************************************************/
      /*    UDF that implements a simplified advective term in the          */
      /*    scalar transport equation                                       */
      /**********************************************************************/
      
      #include "udf.h"
      
      DEFINE_UDS_FLUX(my_uds_flux,f,t,i)
      {
        cell_t  c0,  c1 = -1;
        Thread *t0, *t1 = NULL;
      
        real NV_VEC(psi_vec), NV_VEC(A), flux = 0.0;
      
        c0 = F_C0(f,t);
        t0 = F_C0_THREAD(f,t);
        F_AREA(A, f, t);
      
        /* If face lies at domain boundary, use face values; */
        /* If face lies IN the domain, use average of adjacent cells. */
      
       if (BOUNDARY_FACE_THREAD_P(t)) /*Most face values will be available*/
          {
            real dens;
      
            /* Depending on its BC, density may not be set on face thread*/
            if (NNULLP(THREAD_STORAGE(t,SV_DENSITY)))
              dens = F_R(f,t);   /* Set dens to face value if available */
            else
              dens = C_R(c0,t0); /* else, set dens to cell value */
      
            NV_DS(psi_vec,  =, F_U(f,t), F_V(f,t), F_W(f,t), *, dens);
      
            flux = NV_DOT(psi_vec, A); /* flux through Face */
          }
        else
          {
            c1 = F_C1(f,t);       /* Get cell on other side of face */
            t1 = F_C1_THREAD(f,t); 
      
            NV_DS(psi_vec,  =, C_U(c0,t0),C_V(c0,t0),C_W(c0,t0),*,C_R(c0,t0));
            NV_DS(psi_vec, +=, C_U(c1,t1),C_V(c1,t1),C_W(c1,t1),*,C_R(c1,t1));
      
            flux = NV_DOT(psi_vec, A)/2.0; /* Average flux through face */
          }
      
        /* ANSYS FLUENT will multiply the returned value by phi_f (the scalar's
           value at the face) to get the "complete'' advective term.  */
      
        return flux;
      }
      

      However, I cannot get the result of UDS as you can see in following residual graph.

    • DrAmine
      Ansys Employee
      First of all you do not require UDF to be able to run with UDS. So please do not use the UDF and run again: moreover it seems that you are missing the UDS residula: so pretty sure it shows zero values in the Console residuals: so check its inflow/outflow/wall BC settings.
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