boundary_conditions.templates.hpp

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#include <deal.II/base/vectorization.h>
 
#include <meltpooldg/compressible_flow/boundary_conditions.hpp>
#include <meltpooldg/species_transport/boundary_conditions.hpp>
 
namespace MeltPoolDG::CompressibleFlow
{
  template <int dim, typename number>
  template <typename DofReadView, typename DofWriteView>
  void
  MeltPoolDG::CompressibleFlow::BoundaryConditions<dim, number>::apply_slip_wall_boundary(
    DofReadView                                                    w_m,
    DofWriteView                                                   w_p,
    const dealii::Tensor<1, dim, dealii::VectorizedArray<number>> &normal) const
  {
    // homogeneous Neumann
    w_p.density()      = w_m.density();
    w_p.grad_density() = -(w_m.grad_density());
 
    // homogeneous Neumann
    VectorizedArrayType rho_u_dot_n = 0;
    for (unsigned int d = 0; d < dim; ++d)
      rho_u_dot_n += w_m.momentum(d) * normal[d];
    // symmetry
    for (unsigned int d = 0; d < dim; ++d)
      {
        w_p.momentum(d) = w_m.momentum(d) - 2. * rho_u_dot_n * normal[d];
        w_p.grad_momentum(d) =
          w_m.grad_momentum(d) - 2. * scalar_product(w_m.grad_momentum(d), normal) * normal;
      }
    // homogeneous Neumann
    w_p.grad_total_energy() = -(w_m.grad_total_energy());
    w_p.total_energy()      = w_m.total_energy();
  }
 
  template <int dim, typename number>
  template <typename DofReadView, typename DofWriteView>
  void
  MeltPoolDG::CompressibleFlow::BoundaryConditions<dim, number>::apply_no_slip_wall_boundary(
    DofReadView  w_m,
    DofWriteView w_p) const
  {
    // homogeneous Neumann
    w_p.density()      = w_m.density();
    w_p.grad_density() = -(w_m.grad_density());
 
    // Dirichlet
    for (unsigned int d = 0; d < dim; ++d)
      {
        w_p.momentum(d)      = 0.;
        w_p.grad_momentum(d) = w_m.grad_momentum(d);
      }
    // homogeneous Neumann
    w_p.grad_total_energy() = -(w_m.grad_total_energy());
    w_p.total_energy()      = w_m.total_energy();
  }
 
  template <int dim, typename number>
  template <typename DofReadView, typename DofWriteView, typename DirichletValueInterpretation>
  void
  MeltPoolDG::CompressibleFlow::BoundaryConditions<dim, number>::apply_inflow_boundary(
    const dealii::types::boundary_id                           boundary_id,
    const dealii::Point<dim, dealii::VectorizedArray<number>> &q_point,
    DofReadView                                                w_m,
    DofWriteView                                               w_p,
    const BoundaryType                                         bc_value_type) const
  {
    w_p.density()      = get_boundary_value(boundary_id,
                                       bc_value_type,
                                       q_point,
                                       DirichletValueInterpretation::density);
    w_p.grad_density() = w_m.grad_density();
 
    for (unsigned int d = 0; d < dim; ++d)
      {
        w_p.momentum(d)      = get_boundary_value(boundary_id,
                                             bc_value_type,
                                             q_point,
                                             DirichletValueInterpretation::velocity + d);
        w_p.grad_momentum(d) = w_m.grad_momentum(d);
      }
 
    w_p.total_energy() =
      get_boundary_value(boundary_id, bc_value_type, q_point, DirichletValueInterpretation::energy);
    w_p.grad_total_energy() = w_m.grad_total_energy();
  }
 
  template <int dim, typename number>
  template <typename DofReadView, typename DofWriteView>
  void
  MeltPoolDG::CompressibleFlow::BoundaryConditions<dim, number>::
    apply_subsonic_outflow_with_fixed_pressure_boundary(
      const dealii::types::boundary_id                           boundary_id,
      const dealii::Point<dim, dealii::VectorizedArray<number>> &q_point,
      DofReadView                                                w_m,
      DofWriteView                                               w_p) const
  {
    // homogeneous Neumann
    w_p.density()      = w_m.density();
    w_p.grad_density() = -(w_m.grad_density());
 
    // Dirichlet
    auto p_dyn = dealii::VectorizedArray<number>(0.);
    for (unsigned int i = 0; i < dim; ++i)
      p_dyn += w_m.momentum(i) * w_m.momentum(i);
 
    p_dyn /= (w_m.density() * 2.);
    const dealii::VectorizedArray<number> pressure =
      get_boundary_value(boundary_id, BoundaryType::subsonic_outflow_fixed_pressure, q_point, 0);
 
    // consider equation of state for computation of inner energy from given pressure
    const dealii::VectorizedArray<number> inner_energy = w_m.inner_energy_from_pressure(pressure);
 
    w_p.total_energy()      = inner_energy + p_dyn;
    w_p.grad_total_energy() = w_m.grad_total_energy();
  }
 
  template <int dim, typename number>
  template <typename DofReadView, typename DofWriteView>
  void
  MeltPoolDG::CompressibleFlow::BoundaryConditions<dim, number>::
    apply_subsonic_outflow_with_fixed_energy_boundary(
      const dealii::types::boundary_id                           boundary_id,
      const dealii::Point<dim, dealii::VectorizedArray<number>> &q_point,
      DofReadView                                                w_m,
      DofWriteView                                               w_p) const
  {
    // homogeneous Neumann
    w_p.density()      = w_m.density();
    w_p.grad_density() = -(w_m.grad_density());
    for (unsigned int i = 0; i < dim; ++i)
      {
        w_p.momentum(i)      = w_m.momentum(i);
        w_p.grad_momentum(i) = -(w_m.grad_momentum(i));
      }
 
    // Dirichlet
    w_p.total_energy() =
      get_boundary_value(boundary_id, BoundaryType::subsonic_outflow_fixed_energy, q_point, 0);
    w_p.grad_total_energy() = w_m.grad_total_energy();
  }
 
  template <int dim, typename number>
  template <typename DofReadView, typename DofWriteView>
  void
  MeltPoolDG::CompressibleFlow::BoundaryConditions<dim, number>::
    apply_combined_inflow_no_slip_wall_boundary(
      const dealii::types::boundary_id                           boundary_id,
      const dealii::Point<dim, dealii::VectorizedArray<number>> &q_point,
      DofReadView                                                w_m,
      DofWriteView                                               w_p) const
  {
    dealii::VectorizedArray<number> is_inflow =
      get_boundary_value(boundary_id,
                         BoundaryType::combined_inflow_no_slip_wall,
                         q_point,
                         CombinedInflowNoSlipWallValueInterpretation<dim>::inside_flow);
 
    apply_inflow_boundary<DofReadView,
                          DofWriteView,
                          CombinedInflowNoSlipWallValueInterpretation<dim>>(
      boundary_id, q_point, w_m, w_p, BoundaryType::combined_inflow_no_slip_wall);
 
    auto inflow_density  = w_p.density();
    auto inflow_momentum = w_p.momentum();
    auto inflow_energy   = w_p.total_energy();
 
    auto inflow_grad_density  = w_p.grad_density();
    auto inflow_grad_momentum = w_p.grad_momentum();
    auto inflow_grad_energy   = w_p.grad_total_energy();
 
    apply_no_slip_wall_boundary(w_m, w_p);
 
    auto apply_mask = [](auto mask, auto true_value, auto false_value) -> auto {
      return dealii::compare_and_apply_mask<dealii::SIMDComparison::equal>(
        mask, dealii::VectorizedArray<number>(1.0), true_value, false_value);
    };
 
    w_p.density() = apply_mask(is_inflow, inflow_density, w_p.density());
    for (unsigned int d = 0; d < dim; ++d)
      w_p.grad_density()[d] = apply_mask(is_inflow, inflow_grad_density[d], w_p.grad_density()[d]);
 
    w_p.total_energy() = apply_mask(is_inflow, inflow_energy, w_p.total_energy());
    for (unsigned int d = 0; d < dim; ++d)
      w_p.grad_total_energy()[d] =
        apply_mask(is_inflow, inflow_grad_energy[d], w_p.grad_total_energy()[d]);
 
    for (unsigned int d = 0; d < dim; ++d)
      {
        w_p.momentum(d) = apply_mask(is_inflow, inflow_momentum[d], w_p.momentum(d));
        for (unsigned int d2 = 0; d2 < dim; ++d2)
          w_p.grad_momentum(d)[d2] =
            apply_mask(is_inflow, inflow_grad_momentum[d][d2], w_p.grad_momentum(d)[d2]);
      }
  }
 
 
  template <int dim, typename number>
  template <typename DofReadView, typename DofWriteView>
  void
  MeltPoolDG::CompressibleFlow::BoundaryConditions<dim, number>::
    set_conserved_variables_boundary_value_and_gradient(
      const dealii::Point<dim, dealii::VectorizedArray<number>>     &q_point,
      const dealii::Tensor<1, dim, dealii::VectorizedArray<number>> &normal,
      dealii::types::boundary_id                                     boundary_id,
      const DofReadView                                             &w_m,
      const DofWriteView                                            &w_p) const
  {
    if (const BoundaryType boundary_type = get_boundary_type(boundary_id);
        boundary_type == BoundaryType::slip_wall)
      {
        apply_slip_wall_boundary(w_m, w_p, normal);
      }
    else if (boundary_type == BoundaryType::no_slip_wall)
      {
        apply_no_slip_wall_boundary(w_m, w_p);
      }
    else if (boundary_type == BoundaryType::inflow)
      {
        apply_inflow_boundary(boundary_id, q_point, w_m, w_p);
      }
    else if (boundary_type == BoundaryType::subsonic_outflow_fixed_pressure)
      {
        apply_subsonic_outflow_with_fixed_pressure_boundary(boundary_id, q_point, w_m, w_p);
      }
    else if (boundary_type == BoundaryType::subsonic_outflow_fixed_energy)
      {
        apply_subsonic_outflow_with_fixed_energy_boundary(boundary_id, q_point, w_m, w_p);
      }
    else if (boundary_type == BoundaryType::combined_inflow_no_slip_wall)
      {
        apply_combined_inflow_no_slip_wall_boundary(boundary_id, q_point, w_m, w_p);
      }
    else
      {
        std::cout << "ID: " << boundary_id << std::endl;
        std::cout << "Condition:" << boundary_type << std::endl;
        AssertThrow(false,
                    dealii::ExcMessage("Unknown boundary id, did "
                                       "you set a boundary condition for "
                                       "this part of the domain boundary?"));
      }
  }
 
  template <int dim, typename number>
  template <int n_species, typename DofReadView, typename DofWriteView>
  void
  MeltPoolDG::CompressibleFlow::BoundaryConditions<dim, number>::
    set_partial_density_boundary_value_and_gradient(
      const dealii::Point<dim, dealii::VectorizedArray<number>> &q_point,
      dealii::types::boundary_id                                 boundary_id,
      const DofReadView                                         &w_m,
      const DofWriteView                                        &w_p) const
  {
    if (const BoundaryType boundary_type = get_boundary_type(boundary_id);
        boundary_type == BoundaryType::inflow)
      {
        // For inflow boundary conditions we assume that the partial densities are given and we set
        // them as Dirichlet values.
 
        // Remember for compressible flow we only need to prescribe n_species - 1 partial densities.
        std::array<dealii::VectorizedArray<number>, n_species - 1> dirichlet_boundary_values;
 
        for (unsigned int species = 0; species < n_species - 1; ++species)
          {
            dirichlet_boundary_values[species] =
              get_boundary_value(boundary_id,
                                 BoundaryType::inflow,
                                 q_point,
                                 CompressibleFlow::n_conserved_variables<dim, 1> + species);
          }
 
 
        SpeciesTransport::set_boundary_value_and_gradient(
          w_p, w_m, SpeciesTransport::BoundaryConditionType::dirichlet, dirichlet_boundary_values);
      }
    else if (boundary_type == BoundaryType::combined_inflow_no_slip_wall)
      {
        VectorizedArrayType mask =
          get_boundary_value(boundary_id,
                             BoundaryType::combined_inflow_no_slip_wall,
                             q_point,
                             CombinedInflowNoSlipWallValueInterpretation<dim>::inside_flow);
 
        std::array<dealii::VectorizedArray<number>, n_species - 1> dirichlet_boundary_values;
        for (unsigned int species = 0; species < n_species - 1; ++species)
          {
            dirichlet_boundary_values[species] =
              get_boundary_value(boundary_id,
                                 BoundaryType::combined_inflow_no_slip_wall,
                                 q_point,
                                 CombinedInflowNoSlipWallValueInterpretation<dim>::mass_fractions +
                                   species);
          }
 
        SpeciesTransport::set_boundary_value_and_gradient(
          w_p, w_m, SpeciesTransport::BoundaryConditionType::dirichlet, dirichlet_boundary_values);
 
        std::vector<dealii::VectorizedArray<number>> w_p_partial_densities(n_species - 1);
        for (unsigned int species = 0; species < n_species - 1; ++species)
          w_p_partial_densities[species] = w_p.partial_density(species);
 
        std::vector<dealii::Tensor<1, dim, dealii::VectorizedArray<number>>>
          w_p_partial_density_gradients(n_species - 1);
        for (unsigned int species = 0; species < n_species - 1; ++species)
          w_p_partial_density_gradients[species] = w_p.grad_partial_density(species);
 
        SpeciesTransport::set_boundary_value_and_gradient<n_species - 1,
                                                          dealii::VectorizedArray<number>,
                                                          DofReadView,
                                                          DofWriteView>(
          w_p, w_m, SpeciesTransport::BoundaryConditionType::neumann);
 
        for (unsigned int species = 0; species < n_species - 1; ++species)
          {
            w_p.partial_density(species) =
              dealii::compare_and_apply_mask<dealii::SIMDComparison::equal>(
                mask,
                dealii::VectorizedArray<number>(1.0),
                w_p_partial_densities[species],
                w_p.partial_density(species));
 
            for (unsigned int d = 0; d < dim; ++d)
              w_p.grad_partial_density(species)[d] =
                dealii::compare_and_apply_mask<dealii::SIMDComparison::equal>(
                  mask,
                  dealii::VectorizedArray<number>(1.0),
                  w_p_partial_density_gradients[species][d],
                  w_p.grad_partial_density(species)[d]);
          }
      }
    else
      {
        // For all other boundary conditions we assume homogeneous Neumann for the partial
        // densities.
        SpeciesTransport::set_boundary_value_and_gradient<n_species - 1,
                                                          dealii::VectorizedArray<number>,
                                                          DofReadView,
                                                          DofWriteView>(
          w_p, w_m, SpeciesTransport::BoundaryConditionType::neumann);
      }
  }
} // namespace MeltPoolDG::CompressibleFlow