Exemple #1
0
// Custom function to calculate drag coefficient.
double integrate_over_wall(MeshFunction* meshfn, int marker)
{
  Quad2D* quad = &g_quad_2d_std;
  meshfn->set_quad_2d(quad);

  double integral = 0.0;
  Element* e;
  Mesh* mesh = meshfn->get_mesh();

  for_all_active_elements(e, mesh)
  {
    for(int edge = 0; edge < e->nvert; edge++)
    {
      if ((e->en[edge]->bnd) && (e->en[edge]->marker == marker))
      {
        update_limit_table(e->get_mode());
        RefMap* ru = meshfn->get_refmap();

        meshfn->set_active_element(e);
        int eo = quad->get_edge_points(edge);
        meshfn->set_quad_order(eo, H2D_FN_VAL);
        scalar *uval = meshfn->get_fn_values();
        double3* pt = quad->get_points(eo);
        double3* tan = ru->get_tangent(edge);
        for (int i = 0; i < quad->get_num_points(eo); i++)
          integral += pt[i][2] * uval[i] * tan[i][2];
      }
    }
  }
  return integral * 0.5;
}
Exemple #2
0
//------------------------------------------------------------------------------
// Compute marked boundary length 
//
double CalculateBoundaryLength(Mesh* mesh, int bdryMarker)
{
  // Variables declaration.
  Element* e;
  double length = 0;
  RefMap rm;
  rm.set_quad_2d(&g_quad_2d_std);
  Quad2D * quad = rm.get_quad_2d();
  int points_location;
  double3* points;
  int np;
  double3* tangents;

  // Loop through all boundary faces of all active elements.
  for_all_active_elements(e, mesh) {
    for(int edge = 0; edge < e->nvert; ++edge) {
      if ((e->en[edge]->bnd) && (e->en[edge]->marker == bdryMarker)) {
        rm.set_active_element(e);
        points_location = quad->get_edge_points(edge);
        points = quad->get_points(points_location);
        np = quad->get_num_points(points_location);
        tangents = rm.get_tangent(edge, points_location);
        for(int i = 0; i < np; i++) {
          // Weights sum up to two on every edge, therefore the division by two must be present.
          length +=  0.5 * points[i][2] * tangents[i][2];
        }
      }
    }
  }
  return length;
} // end of CalculateBoundaryLength()