Simple.h

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#ifndef Simple_included
#define Simple_included
 
#include <TRUSTTabs_forward.h>
#include <Simpler_Base.h>
 
class Operateur_Grad ;
 
//Description
 
//Ref. International Journal For Numerical Methods In Fluids Vol. 12 P. 81-92
// C. T. Shaw
 
// A = (M/dt + C(Uk) + D)
// Bt et -B designent respectivement les operateurs gradient et divergence
 
// Une solution (U,P) est recherchee sous la forme suivante :
// U = U* + u'
// P = P* + p'
// ou (U*,P*) est solution de l'equation de q.d.m. et (u',p') est une correction apportee
// a celle-ci pour satisfaire l equation de continuite
 
// (U*,P*) satisfait l equation de q.d.m. :
//        A[Uk-1]U*k = -BtP* + Sv + Ss + (M/dt)Uk-1                -> U*k
//
// En retranchant cette equation a l equation de q.d.m pour (U,P) on a une equation sur  u' et p'
//        A[Uk-1]u' = -Btp'
 
// En ne conservant que la partie diagonale (Da) de A la relation s ecrit :
//        u' = -Da-1Btp'
 
//Le champ complet U satisfait l equation de continuite ce qui donne la relation :
//        -Bu' = BU*
// soit (BDa-1Bt)p' = BU*                                         -> p' puis u'
 
// En fin d iteration la solution s ecrit :
//        U = U* + beta_u u'
//        P = P* + beta_p p'
// beta_u et beta_p sont des coefficients de relaxation compris entre 0 et 1.
// En pratique on applique une relaxation uniquement pour la pression
 
// L algorithme peut etre repete jusqu a convergence du systeme ||Uk-Uk-1|| < seuil_convergence_implicite_
// en pratique on peut ne faire qu une seule iteration (seuil_convergence_implicite_ = 1e6)
 
 
class Simple : public Simpler_Base
{
  Declare_instanciable_sans_constructeur(Simple);
 
public :
 
  Simple();
  bool iterer_eqn(Equation_base& equation, const DoubleTab& inconnue, DoubleTab& result, double dt, int numero_iteration, int& ok) override;
  void iterer_NS(Equation_base&, DoubleTab& current, DoubleTab& pression, double, Matrice_Morse&, double, DoubleTrav&,int nb_iter,int& converge, int& ok) override;
  bool iterer_eqs(LIST(OBS_PTR(Equation_base)) eqs, int compteur, int& ok) override;
 
  /* memoization de iterer_eqs: public pour que la puissance iteree de TRUST-NK puisse la partager */
  using list_of_eq_ptr_t = std::vector<intptr_t>;  // a list of pointers to equations.
  std::map<list_of_eq_ptr_t, Matrice_Bloc> mbloc;
 
protected :
 
  DoubleTab Ustar_old;        //U* = alpha_ U*_new + (1-alpha_)*U*_old   en pratique alpha = 1
  double alpha_,beta_;  //beta_ coefficient de relaxation pour la pression  P = P* + beta_*P'  0<beta_<=1
  int with_d_rho_dt_;
 
  Entree& lire(const Motcle&, Entree&) override;
  void calculer_correction_en_vitesse(const DoubleTrav& correction_en_pression, DoubleTrav& gradP, DoubleTrav& correction_en_vitesse,const Matrice_Morse& matrice, const Operateur_Grad& gradient );
 
};
 
void diviser_par_rho_np1_face(Equation_base& eqn, DoubleTab& tab);
 
#endif