Schema_Euler_Semi_Implicite.cpp

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#include <Schema_Euler_Semi_Implicite.h>
 
Implemente_instanciable(Schema_Euler_Semi_Implicite,"Schema_euler_semi_implicite|Scheme_euler_semi_implicit",Schema_Euler_Implicite);
// XD Schema_euler_semi_implicite schema_implicite_base Schema_euler_semi_implicite INHERITS_BRACE Semi-implicit Euler
// XD_CONT time-integration scheme (parent of Schema_Cahn_Hilliard).
// XD attr theta floattant theta REQ Semi-implicit weight (0 = fully explicit, 1 = fully implicit).
 
Sortie& Schema_Euler_Semi_Implicite::printOn(Sortie& s) const
{
  s << "----------> Coefficient theta for semi-implicit scheme = " << theta_ << finl;
  return  Schema_Euler_Implicite::printOn(s);
}
 
Entree& Schema_Euler_Semi_Implicite::readOn(Entree& s)
{
  Schema_Euler_Implicite::readOn(s);
  Cout << finl;
  Cout << "Semi-implicit Euler time scheme (theta interpolation) is chosen."<< finl;
  Cout << "----------> Coefficient theta for semi-implicit scheme = " << theta_ << finl;
 
  return s;
}
 
void Schema_Euler_Semi_Implicite::set_param(Param& param) const
{
  Schema_Euler_Implicite::set_param(param);
  param.ajouter("theta", &theta_, Param::REQUIRED);
}
 
/*! @brief Renvoie TRUE si le schéma semi-implicite est totalement explicite (important, car theta = 0 pose problème)
 * @return (bool)
 */
bool Schema_Euler_Semi_Implicite::is_explicit()
{
  return abs(theta_) < 1.e-16;
}
 
int Schema_Euler_Semi_Implicite::faire_un_pas_de_temps_pb_couple(Probleme_Couple& pbc, int& ok)
{
  Cerr << "[Schema_Euler_Semi_Implicite] Coupled problems are not taken into account yet." << finl;
  exit();
  return 1;
}
 
int Schema_Euler_Semi_Implicite::faire_un_pas_de_temps_eqn_base(Equation_base& eqn)
{
  DoubleTab& passe = eqn.inconnue().passe();
  DoubleTab& present = eqn.inconnue().valeurs();
  DoubleTab& futur = eqn.inconnue().futur();
  int compteur = 0, ok = 1;
  bool convergence_eqn = false;
  passe = present;
  // futur=present;
  // sert pour la pression et les couplages
  eqn.domaine_Cl_dis().imposer_cond_lim(eqn.inconnue(),temps_courant()+pas_de_temps());
  //present=futur;
 
  // Cas semi-implicite
  if (!is_explicit())
    {
      compteur=0;
      Cout << finl;
      while ((!convergence_eqn)&&(compteur<nb_ite_max))
        {
          compteur++;
          Cout<<"==================================================================================" << finl;
          Cout<<"Schema_Euler_Semi_Implicite: Implicit iteration " << compteur << " on the "<<eqn.que_suis_je() << " equation of the problem "<< eqn.probleme().le_nom()<< " :" <<finl;
          Cout<<"==================================================================================" << finl;
          const DoubleTab& inut=futur;
          // On résout pour un demi-pas de temps
          convergence_eqn=le_solveur->iterer_eqn(eqn, inut, present, theta_*dt_, compteur, ok);
          if (!ok) return 0; //si echec total
          futur=present;
          eqn.domaine_Cl_dis().imposer_cond_lim(eqn.inconnue(),temps_courant()+pas_de_temps());
          present=futur;
        }
      DoubleTrav passe_with_theta(passe);
      passe_with_theta = passe;
      passe_with_theta *= (1 - theta_);
      present -= passe_with_theta;
      present/=theta_;
      update_critere_statio(present, eqn);
      present = passe;
    }
  else
    {
      Cout<<"==================================================================================" << finl;
      Cout<<"Schema_Euler_Semi_Implicite: Explicit case on the "<<eqn.que_suis_je() << " equation of the problem "<< eqn.probleme().le_nom()<< " :" <<finl;
      Cout<<"==================================================================================" << finl;
 
      DoubleTrav dudt(futur); // just for initializing the array structure ... Trav is highly recommanded!! Otherwise we allocate at each time step!!
 
      eqn.inconnue().avancer();
      eqn.derivee_en_temps_inco(dudt);
      eqn.inconnue().reculer();
 
      // Un+1=Un+dt_*dU/dt
      futur = dudt;
      futur *= dt_;
      futur += present;
 
      eqn.domaine_Cl_dis().imposer_cond_lim(eqn.inconnue(), temps_courant() + pas_de_temps());
      update_critere_statio(dudt, eqn);
 
    }
 
  return 1;
}