Example #1
0
int main(int argc, char* argv[])
{
  // Load the mesh.
  MeshSharedPtr mesh(new Mesh);
  MeshReaderH2D mloader;
  mloader.load("domain.mesh", mesh);

  // Initial mesh refinements.
  mesh->refine_towards_boundary(BDY_OBSTACLE, 2, false);
  mesh->refine_towards_boundary(BDY_TOP, 2, true);     // '4' is the number of levels,
  mesh->refine_towards_boundary(BDY_BOTTOM, 2, true);  // 'true' stands for anisotropic refinements.
  mesh->refine_all_elements();

  // Initialize boundary conditions.
  EssentialBCNonConst bc_left_vel_x(BDY_LEFT, VEL_INLET, H, STARTUP_TIME);
  Hermes::Hermes2D::DefaultEssentialBCConst<double> bc_other_vel_x(Hermes::vector<std::string>(BDY_BOTTOM, BDY_TOP, BDY_OBSTACLE), 0.0);
  Hermes::Hermes2D::EssentialBCs<double> bcs_vel_x(Hermes::vector<EssentialBoundaryCondition<double> *>(&bc_left_vel_x, &bc_other_vel_x));
  Hermes::Hermes2D::DefaultEssentialBCConst<double> bc_vel_y(Hermes::vector<std::string>(BDY_LEFT, BDY_BOTTOM, BDY_TOP, BDY_OBSTACLE), 0.0);
  Hermes::Hermes2D::EssentialBCs<double> bcs_vel_y(&bc_vel_y);
  Hermes::Hermes2D::EssentialBCs<double> bcs_pressure;

  // Spaces for velocity components and pressure.
  SpaceSharedPtr<double> xvel_space(new H1Space<double>(mesh, &bcs_vel_x, P_INIT_VEL));
  SpaceSharedPtr<double> yvel_space(new H1Space<double>(mesh, &bcs_vel_y, P_INIT_VEL));
#ifdef PRESSURE_IN_L2
  SpaceSharedPtr<double> p_space(new L2Space<double> (mesh, P_INIT_PRESSURE));
#else
  SpaceSharedPtr<double> p_space(new H1Space<double> (mesh, &bcs_pressure, P_INIT_PRESSURE));
#endif

  // Calculate and report the number of degrees of freedom.
  int ndof = Space<double>::get_num_dofs(Hermes::vector<SpaceSharedPtr<double> >(xvel_space, yvel_space, p_space));

  // Define projection norms.
  NormType vel_proj_norm = HERMES_H1_NORM;
#ifdef PRESSURE_IN_L2
  NormType p_proj_norm = HERMES_L2_NORM;
#else
  NormType p_proj_norm = HERMES_H1_NORM;
#endif

  // Solutions for the Newton's iteration and time stepping.
  MeshFunctionSharedPtr<double> xvel_prev_time(new ConstantSolution<double> (mesh, 0.0));
  MeshFunctionSharedPtr<double> yvel_prev_time(new ConstantSolution<double> (mesh, 0.0));
  MeshFunctionSharedPtr<double> p_prev_time(new ConstantSolution<double> (mesh, 0.0));

  // Initialize weak formulation.
  WeakFormNSNewton wf(STOKES, RE, TAU, xvel_prev_time, yvel_prev_time);
  UExtFunctionSharedPtr<double> fn_0(new CustomUExtFunction(0));
  UExtFunctionSharedPtr<double> fn_1(new CustomUExtFunction(1));
  wf.set_ext(Hermes::vector<MeshFunctionSharedPtr<double> >(xvel_prev_time, yvel_prev_time));
  wf.set_u_ext_fn(Hermes::vector<UExtFunctionSharedPtr<double> >(fn_0, fn_1));

  // Initialize the Newton solver.
  Hermes::Hermes2D::NewtonSolver<double> newton;
  newton.set_weak_formulation(&wf);
  Hermes::vector<SpaceSharedPtr<double> > spaces(xvel_space, yvel_space, p_space);
  newton.set_spaces(spaces);

  // Initialize views.
  Views::VectorView vview("velocity[m/s]", new Views::WinGeom(0, 0, 750, 240));
  Views::ScalarView pview("pressure[Pa]", new Views::WinGeom(0, 290, 750, 240));
  vview.set_min_max_range(0, 1.6);
  vview.fix_scale_width(80);
  //pview.set_min_max_range(-0.9, 1.0);
  pview.fix_scale_width(80);
  if(HERMES_VISUALIZATION)
    pview.show_mesh(true);

  // Project the initial condition on the FE space to obtain initial
  // coefficient vector for the Newton's method.
  double* coeff_vec = new double[Space<double>::get_num_dofs(Hermes::vector<SpaceSharedPtr<double> >(xvel_space, yvel_space, p_space))];
  OGProjection<double> ogProjection;

  ogProjection.project_global(Hermes::vector<SpaceSharedPtr<double> >(xvel_space, yvel_space, p_space),
    Hermes::vector<MeshFunctionSharedPtr<double> >(xvel_prev_time, yvel_prev_time, p_prev_time),
    coeff_vec, Hermes::vector<NormType>(vel_proj_norm, vel_proj_norm, p_proj_norm));

  newton.set_max_allowed_iterations(max_allowed_iterations);
  newton.set_tolerance(NEWTON_TOL, Hermes::Solvers::ResidualNormAbsolute);
  newton.set_sufficient_improvement_factor_jacobian(1e-2);
  //newton.set_jacobian_constant();

  // Time-stepping loop:
  char title[100];
  int num_time_steps = T_FINAL / TAU;
  for (int ts = 1; ts <= num_time_steps; ts++)
  {
    current_time += TAU;
    Hermes::Mixins::Loggable::Static::info("Time step %i, time %f.", ts, current_time);

    // Update time-dependent essential BCs.
    newton.set_time(current_time);

    // Perform Newton's iteration and translate the resulting coefficient vector into previous time level solutions.
    try
    {
      newton.solve(coeff_vec);
    }
    catch(Hermes::Exceptions::Exception& e)
    {
      e.print_msg();
    }
    Hermes::vector<MeshFunctionSharedPtr<double> > tmp(xvel_prev_time, yvel_prev_time, p_prev_time);
    Hermes::Hermes2D::Solution<double>::vector_to_solutions(newton.get_sln_vector(), 
      Hermes::vector<SpaceSharedPtr<double> >(xvel_space, yvel_space, p_space), tmp);

    // Show the solution at the end of time step.
    if(HERMES_VISUALIZATION)
    {
      sprintf(title, "Velocity, time %g", current_time);
      vview.set_title(title);
      vview.show(xvel_prev_time, yvel_prev_time);
      sprintf(title, "Pressure, time %g", current_time);
      pview.set_title(title);
      pview.show(p_prev_time);
    }
  }

  delete [] coeff_vec;

  return 0;
}
Example #2
0
int main(int argc, char* argv[])
{
#ifdef THREAD_TESTING
  HermesCommonApi.set_integral_param_value(numThreads, 8);
#endif
  // Load the mesh.
  MeshSharedPtr mesh(new Mesh);
  Hermes::vector<MeshSharedPtr> meshes;
  meshes.push_back(mesh);
  MeshReaderH2DXML mloader;
  mloader.load("agrosMesh.msh", meshes);

  // Perform initial mesh refinements.
  for (int i = 0; i < INIT_REF_NUM; i++)
    mesh->refine_all_elements();

  // Initialize boundary conditions.
  DefaultEssentialBCConst<complex> bc_essential("4", P_SOURCE);
  EssentialBCs<complex> bcs(&bc_essential);

  // Create an H1 space with default shapeset.
  SpaceSharedPtr<complex> space(new H1Space<complex> (mesh, &bcs, P_INIT));
  adaptivity.set_space(space);

  // Initialize the weak formulation.
  CustomWeakFormAcoustics wf("0", RHO, SOUND_SPEED, OMEGA);

  // Initialize coarse and reference mesh solution.
  MeshFunctionSharedPtr<complex>  sln(new Solution<complex>), ref_sln(new Solution<complex>);

  // Initialize refinement selector.
  H1ProjBasedSelector<complex> selector(CAND_LIST);

  Hermes::Hermes2D::NewtonSolver<complex> newton;
  newton.set_weak_formulation(&wf);

  // 2 Adaptivity steps:
  int as = 1;
  bool done = false;
  do
  {
    // Construct globally refined reference mesh and setup reference space.
    Mesh::ReferenceMeshCreator refMeshCreator(mesh);
    MeshSharedPtr ref_mesh = refMeshCreator.create_ref_mesh();

    Space<complex>::ReferenceSpaceCreator refSpaceCreator(space, ref_mesh);
    SpaceSharedPtr<complex> ref_space = refSpaceCreator.create_ref_space();

    // Perform Newton's iteration.
    try
    {
      newton.set_space(ref_space);
      newton.solve();
    }
    catch(Hermes::Exceptions::Exception& e)
    {
      e.print_msg();
      throw Hermes::Exceptions::Exception("Newton's iteration failed.");
    };

    // Translate the resulting coefficient vector into the Solution<complex> sln->
    Hermes::Hermes2D::Solution<complex>::vector_to_solution(newton.get_sln_vector(), ref_space, ref_sln);

    // Project the fine mesh solution onto the coarse mesh.
    OGProjection<complex> ogProjection; ogProjection.project_global(space, ref_sln, sln);
    
    // Calculate element errors and total error estimate.
    errorCalculator.calculate_errors(sln, ref_sln);
    adaptivity.adapt(&selector);
  }
  while (as++ < 2);
  return 0;
}