Schema_Euler_explicite.cpp

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#include <Schema_Euler_explicite.h>
#include <Equation_base.h>
 
Implemente_instanciable(Schema_Euler_explicite,"Schema_euler_explicite|Scheme_euler_explicit",TRUSTSchema_RK<Ordre_RK::UN>);
// XD euler_scheme schema_temps_base schema_euler_explicite INHERITS_BRACE This is the Euler explicit scheme.
 
Sortie& Schema_Euler_explicite::printOn(Sortie& s) const { return  TRUSTSchema_RK<Ordre_RK::UN>::printOn(s); }
 
Entree& Schema_Euler_explicite::readOn(Entree& s) { return TRUSTSchema_RK<Ordre_RK::UN>::readOn(s) ; }
 
/*! @brief Performs an explicit Euler time step on the equation passed as parameter.
 *
 */
int Schema_Euler_explicite::faire_un_pas_de_temps_eqn_base(Equation_base& eqn)
{
  DoubleTab& present = eqn.inconnue().valeurs(); // Un
  DoubleTab& futur = eqn.inconnue().futur();   // Un+1
  DoubleTrav dudt(futur); // just for initializing the array structure ... Trav is highly recommanded!! Otherwise we allocate at each time step!!
 
  /*
   * The strategy done in the explicit schemes is to prescribe CL at time n+1
   *  at the begining of the time step, turning the wheel (avancer/reculer) to use
   *  it in derivee_en_temps_inco (so that valeurs() points to futur() only for BC).
   *
   * It influences only two cases
   *     - Time dependent BCs (champ_fonc_txyz ou ICoCo) or function (champ_fonc_fonction) => Here it only shifts the
   *        applied BC by one time step, but does not change the order of the scheme
   *
   *     - Coupled cases (paroi contact) => Here it is mandatory to have the equality of the fluxes at the coupled boundary
   *
   *     See the out files of docond/docond_vef
   */
 
  // Boundary conditions applied on Un+1:
  eqn.domaine_Cl_dis().imposer_cond_lim(eqn.inconnue(), temps_courant() + pas_de_temps());
 
  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;
}