Viscosite_turbulente_WALE.cpp

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#include <Viscosite_turbulente_WALE.h>
#include <Discretisation_base.h>
#include <Champ_Face_base.h>
#include <Pb_Multiphase.h>
#include <Domaine_VF.h>
#include <Param.h>
 
Implemente_instanciable(Viscosite_turbulente_WALE, "Viscosite_turbulente_WALE", Viscosite_turbulente_LES_base);
// XD type_diffusion_turbulente_multiphase_wale type_diffusion_turbulente_multiphase_deriv wale BRACE LES WALE type.
 
Sortie& Viscosite_turbulente_WALE::printOn(Sortie& os) const { return os; }
 
Entree& Viscosite_turbulente_WALE::readOn(Entree& is)
{
  mod_const_ = 0.5; // par default
  Param param(que_suis_je());
  param.ajouter("cw", &mod_const_); // XD_ADD_P floattant
  // XD_CONT WALE's model constant. By default it is se to 0.5.
  param.lire_avec_accolades_depuis(is);
 
  if (mod_const_ < 0.) Process::exit("The WALE's constant must be positive !");
  else Cerr << "LES WALE model used with constant CW = " << mod_const_ << finl;
 
  return Viscosite_turbulente_LES_base::readOn(is);
}
 
/*
 *                                               (Sij_d * Sij_d)^1.5
 *    visc_SGS = (Cw * delta)^2 * ---------------------------------------------------,
 *                                  (Sij_bar * Sij_bar)^2.5 + (Sij_d * Sij_d)^1.25
 *
 *    avec
 *
 *        Sij_d = 0.5 * (gij_bar^2 + gji_bar^2) -1/3 gkk_bar^2,
 *        gij_bar = du_i / dx_j,
 *        gij_bar^2 = gik_bar * gkj_bar,
 *        Sij_bar = 0.5 * (du_i / dx_j + du_j / dx_i)
 */
void Viscosite_turbulente_WALE::eddy_viscosity(DoubleTab& nu_t) const
{
  if (est_egal(mod_const_, 0., 1.e-15)) nu_t = 0.;
  else
    {
      const Domaine_VF& domaine_VF = ref_cast(Domaine_VF, pb_->domaine_dis());
      const Champ_Face_base& vit = ref_cast(Champ_Face_base, pb_->equation(0).inconnue());
 
      // Nota bene : en PolyMAC_MPFA, grad_u__ contient (nf.grad)u_i aux faces, puis (d_j u_i) aux elements
      const DoubleTab& grad_u__ = pb_->get_champ("gradient_vitesse").valeurs();
 
      const IntTab& face_voisins = domaine_VF.face_voisins(), &elem_faces = domaine_VF.elem_faces();
      const int nb_elem_tot = domaine_VF.nb_elem_tot(), dim = Objet_U::dimension, N = vit.valeurs().line_size();
      const bool is_poly = pb_->discretisation().is_poly_family();
      const int nb_faces_tot = is_poly ? domaine_VF.nb_faces_tot() : 0;
      assert (N == nu_t.dimension(1));
 
      DoubleTrav num_sur_denom(nb_elem_tot, nu_t.dimension(1));
      num_sur_denom = 0.;
 
      DoubleTrav grad_u(nb_elem_tot, dim, dim, N), gij_bar2(dim, dim, N), Sij_d(dim, dim, N);
      grad_u = 0., gij_bar2 = 0., Sij_d = 0.;
 
      // remplir grad_u en 4 dimension
      // XXX : attention faut remplir grad_u ici pas plus tard !!!
      for (int elem = 0; elem < nb_elem_tot; elem++)
        for (int i = 0; i < dim; i++) // variable : du, dv, dw
          for (int j = 0; j < dim; j++) // par rappor a : dx, dy, dz
            for (int n = 0; n < N; n++) // phase
              grad_u(elem, i, j, n) = is_poly ? grad_u__(nb_faces_tot + elem * dim + j, n * dim + i) : grad_u__(nb_faces_tot + elem, N * (dim * i + j) + n);
 
      // Arrays utiles
      ArrOfDouble gkk_bar2(N), Sij_d2(N), Sij_bar(N), Sij_bar2(N);;
 
      for (int elem = 0; elem < nb_elem_tot; elem++)
        {
          //Calcul du terme Sij_d
          for (int i = 0; i < dim; i++)
            for (int j = 0; j < dim; j++)
              for (int n = 0; n < N; n++)
                {
                  gij_bar2(i, j, n) = 0.;
                  for (int k = 0; k < dim; k++)
                    gij_bar2(i, j, n) += grad_u(elem, i, k, n) * grad_u(elem, k, j, n);
                }
 
          gkk_bar2 = 0.;
          for (int k = 0; k < dim; k++)
            for (int n = 0; n < N; n++)
              gkk_bar2(n) += gij_bar2(k, k, n);
 
          for (int i = 0; i < dim; i++)
            for (int j = 0; j < dim; j++)
              for (int n = 0; n < N; n++)
                {
                  Sij_d(i, j, n) = 0.5 * (gij_bar2(i, j, n) + gij_bar2(j, i, n));
                  if (i == j)
                    Sij_d(i, j, n) -= gkk_bar2(n) / 3.; // Terme derriere le tenseur de Kronecker
                }
 
          // Calcul de Sij_d2 et Sij_bar2
          Sij_d2 = 0., Sij_bar = 0., Sij_bar2 = 0.;
 
          for (int i = 0; i < dim; i++)
            for (int j = 0; j < dim; j++)
              for (int n = 0; n < N; n++)
                {
                  Sij_d2(n) += Sij_d(i, j, n) * Sij_d(i, j, n);
 
                  // Sij_bar et Sij_bar2
                  Sij_bar(n) = 0.5 * (grad_u(elem, i, j, n) + grad_u(elem, j, i, n));
                  if (i == j)
                    {
                      const int face1 = elem_faces(elem, i), face2 = elem_faces(elem, i + dim), elem1 = face_voisins(face1, 0), elem2 = face_voisins(face2, 1);
 
                      if (elem1 >= 0 && elem2 >= 0)
                        Sij_bar(n) = ((grad_u(elem1, i, i, 0) + grad_u(elem, i, i, 0) + grad_u(elem2, i, i, 0))) / 3.;
                    }
                  Sij_bar2(n) += Sij_bar(n) * Sij_bar(n);
                }
 
          for (int n = 0; n < N; n++)
            {
              const double num = pow(Sij_d2(n), 1.5), denom = pow(Sij_bar2(n), 2.5) + pow(Sij_d2(n), 1.25);
              num_sur_denom(elem, n) = num != 0. ? (num / denom) : 0.;
            }
        }
 
      for (int i = 0; i < nu_t.dimension(0); i++)
        for (int n = 0; n < nu_t.dimension(1); n++)
          nu_t(i, n) = mod_const_ * mod_const_ * l_(i) * l_(i) * num_sur_denom(i, n);
 
      nu_t.echange_espace_virtuel();
    }
}