Eval_Puiss_Th_DG_Elem.h

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#ifndef Eval_Puiss_Th_DG_Elem_included
#define Eval_Puiss_Th_DG_Elem_included
 
#include <Evaluateur_Source_Elem.h>
#include <Champ_Uniforme.h>
#include <Equation_base.h>
#include <Champ_Don_base.h>
#include <TRUST_Ref.h>
#include <TRUSTTab.h>
#include <Champ_Elem_DG.h>
#include <Domaine_DG.h>
#include <BasisFunction.h>
 
/**
 * @brief Evaluator computing the volumetric heat source contribution for DG element unknowns.
 *
 * For each element e, this evaluator computes the projection of the volumetric heat
 * power density Q onto each basis function phi_i:
 *   S(i) = integral of Q(x) * phi_i(x) dV
 * using a fixed order-5 quadrature rule. The power field Q is expected to be
 * pre-evaluated at the quadrature points and stored in the puissance array
 * (shape: nb_elem x nb_pts_integ_max), as set up by associer_champs().
 *
 * calculer_terme_source() is templated on Type_Double to allow both scalar and
 * small-vector output types
 *
 * @sa Terme_Puissance_Thermique_DG_Elem, Evaluateur_Source_Elem
 */
class Eval_Puiss_Th_DG_Elem: public Evaluateur_Source_Elem
{
public:
  void mettre_a_jour() override { }
  void associer_champs(const Champ_Don_base&);
 
  template <typename Type_Double>
  inline void calculer_terme_source(const int, Type_Double&) const;
 
protected:
  OBS_PTR(Champ_Don_base) la_puissance;
  DoubleTab puissance;
};
 
/**
 * @brief Computes the heat source projection onto the local DG basis for element e.
 *
 * @details Evaluates the integral S(fb) = integral of Q * phi_fb over element e
 * using a fixed order-5 quadrature. The integrand at each quadrature point k is:
 *   product(k) = puissance(e, k) * fbase(fb, k)
 * where puissance contains Q pre-sampled at quadrature points and fbase contains
 * the basis function values from eval_bfunc().
 *
 * @tparam Type_Double Output type (typically a fixed-size array of nb_bfunc values).
 * @param e  Element index.
 * @param S  Output array of size nb_bfunc, filled with the projected source values.
 */
template <typename Type_Double>
inline void Eval_Puiss_Th_DG_Elem::calculer_terme_source(const int e, Type_Double& S) const
{
  const Champ_Elem_DG& ch = ref_cast(Champ_Elem_DG, la_zcl->inconnue());
  const Nom& nom_inc = ch.le_nom();
 
  const Domaine_DG& dom = ref_cast(Domaine_DG, le_dom.valeur());
 
  int order = Option_DG::Get_order_for(nom_inc);
 
  const BasisFunction& bfunc = dom.get_basisFunction(order);
  const int nb_bfunc = bfunc.nb_bfunc();
 
  const Quadrature_base& quad = dom.get_quadrature(5);
  int nb_pts_integ_max = quad.nb_pts_integ_max();
 
  DoubleTab product(nb_pts_integ_max);
 
  DoubleTab fbase(nb_bfunc, nb_pts_integ_max);
  bfunc.eval_bfunc(quad, e, fbase);
 
  for (int fb = 0; fb < nb_bfunc; fb++)
    {
      for (int k = 0; k < quad.nb_pts_integ(e) ; k++)
        product(k) = puissance(e,k) * fbase(fb, k);
 
      S(fb) = quad.compute_integral_on_elem(e, product);
    }
}
 
#endif /* Eval_Puiss_Th_DG_Elem_included */