Page:4SIGHT manual- a computer program for modelling degradation of underground low level waste concrete vaults (IA 4sightmanualcomp5612snyd).pdf/129

54. Ion transport.

⟨Function declarations 23⟩ $+\equiv$
 void ion-diffusion (void);

55. ion-diffusion.

void ion-diffusion ()
{ 
  int i, j, k
  real cation_flux [10][NUM_SURFACES], anion.flux [10][NUM_SURFACES], upper_limit=$5.0\cdot 10^{+04}$,
      lower_limit = 5.0\codt10^{+03}, max_flux_ratio;
  real tmp.cation [10][NUM_SURFACES], tmp.anion [10][NUM_SURFACES];
  $\Delta X$[FIRST_CELL] = (real) (FIRST.CELL+1) - sulfate-depth;
  max_flux.ratio = 0.0;
  for(i = 0; i < num-cations ; i++) {
    for(k=FIRST.CELL + 1; k < NUM.SURFACES - 1; k++) {
      cation_flux [i].c[k] = cation[i].$\eta$ * (\xi[k] * cation [i].c[k + 1]- cation[i].c[k])/\$DeltaX$[k]-$\eta$[k-1]* (cation[i].c[k]-cation[i].c[k-1])/$\Delta X$[k-1])/(0.5 * ($\Delta X$[k] + $\Delta X$[k-1]));
      cation_flux[i][k]-=(1./$\phi '^{n}$[k])*v[k]*((cation[i].c[k+1]-cation[i].c[k-1])/($\Delta X$[k]+($\Delta X$[k-1]));
      if(cation[i].c[k]>0.0)
        max_flux_ratio=MAX(max_flux_ration,$\Delta T$*cation_flux[i][k]/cation[i].c[k]);
    }
 }
 for( j=0; j < num_anions; j++) {
   for (k = FIRST_CELL_1; k < NUM_SURFACES-1; k++) {
     anion_flux[j][k]=anion[j].$\eta$*($\xi$[k] *(anion[j].c[k+1]- anion[j].c[k])/$\Delta X$[k]-$\eta$[k-1]*(anion[j].c[k]-anion[j].c[k-1]/$\Delta X$[k-1])/(0.5*($\Delta X$[k]+$\Delta X$[k-1]));
     anion_flux[j][k]-=(1.$\phi '^{n}$v[k] *((anion[j].c[k+1]-anion[j].c[k-1])/(\Delta X)[k]+$\Delta X$[k-1])));
     if (anion[j].c[k]>0.0)
       max_flux_ratio = MAX (max_flux_ratio, $\Delta T$ * anion_flux[j][k]/anion[j].c[k]);
   }
 }
 if(max_flux_ration > upper_limt) $\Delta T$*= upper_limit/max_flux_ratio;
 if(max_flux_ration < lower_limt) $\Delta T$*= upper_limit/max_flux_ratio;
 for(k= FIRST_CELL+1; k<NUM_SURFACES-1;k++) {
   for(i=0; i< num_cations; i++) cation[i].c[k]+=$\delta T$*cation_flux[i][k];
   for(j=0; j< num_cations; j++) cation[j].c[k]+=$\delta T$*cation_flux[j][k];
 }
 k=NUM_SURFACES-1;
 for(i=0;i<num_cations;i++) cation[i].c[k]=cation[i].c[k-1]
 for(j=0;j<num_cations;j++) cation[j].c[k]=cation[j].c[k-1]
 for(i=0;i< num_cations; i++)
   for(k=FIRST_CELL; k < NUM_SURFACES; k++)
     cation[i].moles[k]=cation[i].c[k] * litre[k]*$\Delta X$[k];
 for(j=0;i< num_anions; j++)
   for(k=FIRST_CELL; k < NUM_SURFACES; k++)
     anion[i].moles[k]=anion[i].c[k] * litre[k]*$\Delta X$[k];
  }