[brucelqs]

Hi all, I have encountered a problem. After I implanted the anisotropic conductivity UDF in the fluent fuel cell module, and clicked the "Calculate" button, the program did not run, and the following error message popped up when I exited the software "Error at Node 0: No anisotropic UDS diffusivity option" has been selected for difflayer". I tried to add the anisotropic conductivity of UDS-0 (i.e. electron potential) within the source code and through UDF, but both failed. Please help me, I don't know where the problem is.

Here is the code I use inside the source code (pemfc_user.c):

DEFINE_ANISOTROPIC_DIFFUSIVITY(aniso_econd, c, t, i, dmatrix)
{
  anisotropic_elec_cond(c, t, i, dmatrix);
    
  if (pem_initialized && User_Defined_Non_Iso_Econd)
  {
    int zt = get_fc_zone_type(t->id);

    if (zt == adl_zone || zt == cdl_zone || zt == amp_zone || zt == cmp_zone)
    {
      /*--- In this section, users can redefine the "dmatrix" that was computed above for GDL andd MPL only ---*/
        real por, ip, tp, tri, trp;
        por = C_POR(c, t);
        ip = 1. - (3. * por / (2. + por)) * 0.962 * exp(0.367 * (1. - por)) * pow(1. - por, -0.016);
        tp = 1. - (3. * por / (2. + por)) * 0.962 * exp(0.889 * (1. - por)) * pow(1. - por, -0.00715);
        tri = sqrt(ip);
        trp = sqrt(tp);
        real x[3][3];
        static const real diff[3] = { 23000.,23000.,23000. }; //diff is inherent conductivity
        x[1][0] = x[0][1] = 0.0;
        x[2][0] = x[0][2] = 0.0;
        x[2][1] = x[1][2] = 0.0;
        x[2][2] = x[0][0] = tri;
        x[1][1] = trp;

        dmatrix[0][0] = diff[0] * x[0][0] * x[0][0] 
            + diff[1] * x[1][0] * x[1][0]   
            + diff[2] * x[2][0] * x[2][0];  //XX direction,x[1][0]=0,x[2][0]=0
        dmatrix[1][1] = diff[0] * x[0][1] * x[0][1] 
            + diff[1] * x[1][1] * x[1][1]   
            + diff[2] * x[2][1] * x[2][1];  //YY direction,x[0][1]=0,x[2][1]=0
        dmatrix[1][0] = diff[0] * x[0][1] * x[0][0]
            + diff[1] * x[1][1] * x[1][0]
            + diff[2] * x[2][1] * x[2][0];  //dmatrix[1][0]=0
        dmatrix[0][1] = dmatrix[1][0];  //dmatrix[0][1]=0
        dmatrix[2][2] = diff[0] * x[0][2] * x[0][2] 
            + diff[1] * x[1][2] * x[1][2]   
            + diff[2] * x[2][2] * x[2][2];  //ZZ direction,x[0][2]=0,x[1][2]=0
        dmatrix[0][2] = diff[0] * x[0][0] * x[0][2]
            + diff[1] * x[1][0] * x[1][2]
            + diff[2] * x[2][0] * x[2][2];  //dmatrix[0][2]=0
        dmatrix[2][0] = dmatrix[0][2];  //dmatrix[2][0]=0
        dmatrix[1][2] = diff[0] * x[0][1] * x[0][2]
            + diff[1] * x[1][1] * x[1][2]
            + diff[2] * x[2][1] * x[2][2];  //dmatrix[1][2]=0
        dmatrix[2][1] = dmatrix[1][2];  //dmatrix[2][1]=0
    }
  }

  return;
}

I turned on the "Anisotropic E-cond. in GDL/MPL" option in the module, hooked the UDF in the material of GDL and MPL, I tried using the "orthotropic" option, the anisotropic conductivity option was able to calculate correctly , but it fails after loading the UDF.

Below is a screenshot from the software:
1.jpg

2.jpg

3.png