fixed_length.hpp

 
#ifndef __FIXED_LENGTH_MODEL_HPP__
#define __FIXED_LENGTH_MODEL_HPP__
 
#include <Kokkos_Core_fwd.hpp>
#include <Kokkos_Macros.hpp>
#include <common/common.hpp>
#include <common/traits.hpp>
#include <mc/alias.hpp>
#include <mc/macros.hpp>
#include <mc/prng/prng_extension.hpp>
#include <mc/traits.hpp>
#include <models/utils.hpp>
#include <string_view>
 
namespace Models
{
  struct FixedLength
  {
    using uniform_weight = std::true_type;
    using Self = FixedLength;
    using FloatType = double;
 
    using Config = Kokkos::View<const FloatType*, ComputeSpace>;
 
    enum class particle_var : int // NOLINT
    {
      length = 0,
      l_max,
      __COUNT__
    };
 
    MODEL_CONSTANT std::size_t n_var = INDEX_FROM_ENUM(particle_var::__COUNT__);
 
    MODEL_CONSTANT std::size_t n_c = 1;
 
    MODEL_CONSTANT std::string_view name = "fixed-length";
    using SelfParticle = MC::ParticlesModel<Self::n_var, Self::FloatType>;
    using SelfContribs = MC::ParticlesContribs<Self::n_c, Self::FloatType>;
 
    MODEL_CONSTANT FloatType l_dot_max = 20e-6 / 3600.; // m
    MODEL_CONSTANT FloatType l_max_m = 2e-6;            // m
    MODEL_CONSTANT FloatType l_min_m = l_max_m / 2.;    // m
    MODEL_CONSTANT FloatType k = 1e-3;                  // m
    MODEL_CONSTANT FloatType d_m = 0.6e-6;              // m
    MODEL_CONSTANT FloatType lin_density
        = c_linear_density(static_cast<FloatType>(1000), d_m);
 
    MODEL_CONSTANT FloatType phi_s_max
        = _get_phi_s_max<FloatType>(lin_density, l_dot_max); // kgS/s
 
    MC::ContribIndexBounds static get_bounds();
 
    static Self::Config get_config(const ExecInfo& info, std::size_t n);
 
    static bool use_contribs;
 
    KOKKOS_INLINE_FUNCTION static void init(const MC::pool_type& random_pool,
                                            std::size_t idx,
                                            const SelfParticle& arr,
                                            const Config& params);
 
    KOKKOS_INLINE_FUNCTION static MC::Status
    update(const MC::pool_type& random_pool,
           FloatType d_t,
           std::size_t idx,
           const SelfParticle& arr,
           const SelfContribs& arr_contribs,
           std::size_t position_index,
           const MC::LocalConcentration& c);
 
    KOKKOS_INLINE_FUNCTION static void
    division(const MC::pool_type& random_pool,
             std::size_t idx,
             std::size_t idx2,
             const SelfParticle& arr,
             const SelfParticle& buffer_arr);
 
    KOKKOS_INLINE_FUNCTION static double
    mass(std::size_t idx, const SelfParticle& arr)
    {
      return GET_PROPERTY(Self::particle_var::length) * lin_density;
    }
 
    static std::vector<std::string_view>
    names()
    {
      return {
 
        "length",
      };
    }
 
    static std::vector<std::size_t>
    get_number()
    {
 
      return { INDEX_FROM_ENUM(particle_var::length) };
    }
 
    static std::vector<std::string_view>
    species()
    {
      return { "S" };
    }
  };
 
  CHECK_MODEL(FixedLength)
 
  KOKKOS_INLINE_FUNCTION void
  FixedLength::init([[maybe_unused]] const MC::pool_type& random_pool,
                    std::size_t idx,
                    const SelfParticle& arr,
                    const Config& config)
  {
    auto gen = random_pool.get_state();
    const auto linit = config(idx);
    random_pool.free_state(gen);
    GET_PROPERTY(particle_var::length) = linit;
    GET_PROPERTY(particle_var::l_max) = l_max_m;
    // GET_PROPERTY(particle_var::phi_s) = 0.;
  }
 
  KOKKOS_INLINE_FUNCTION MC::Status
  FixedLength::update([[maybe_unused]] const MC::pool_type& random_pool,
                      FloatType d_t,
                      std::size_t idx,
                      const SelfParticle& arr,
                      const SelfContribs& arr_contribs,
                      const std::size_t position_index,
                      const MC::LocalConcentration& c)
  {
    auto& l = GET_PROPERTY(Self::particle_var::length);
    const auto l_max = GET_PROPERTY(Self::particle_var::l_max);
    const auto s = static_cast<FloatType>(GET_CONCENTRATION(0));
    auto& c_phi_s = GET_CONTRIBS(0);
    //    static auto f_c = use_contribs;
    //
    auto f_c = false;
    const FloatType g = (f_c) ? s / (k + s) : FloatType{ 1 };
    const FloatType phi_s = phi_s_max * g;
    const FloatType ldot = l_dot_max * g;
    //    auto gen = random_pool.get_state();
    const auto alpha = 0.F; // Kokkos::sqrt(2.F * 1e-17 * d_t) * gen.normal();
                            //   random_pool.free_state(gen);
 
    l += d_t * ldot + alpha;
    c_phi_s = -phi_s;
    return check_div(l, l_max);
  }
 
  KOKKOS_INLINE_FUNCTION void
  FixedLength::division([[maybe_unused]] const MC::pool_type& random_pool,
                        std::size_t idx,
                        std::size_t idx2,
                        const SelfParticle& arr,
                        const SelfParticle& buffer_arr)
  {
 
    // const FloatType new_current_length
    //     = GET_PROPERTY(particle_var::length) / 2.F;
 
    const FloatType new_current_length
        = GET_PROPERTY(particle_var::length)
          - GET_PROPERTY(particle_var::l_max) / 2.F;
 
    GET_PROPERTY(particle_var::length) = new_current_length;
    GET_PROPERTY(particle_var::l_max) = l_max_m;
 
    GET_PROPERTY_FROM(idx2, buffer_arr, particle_var::length)
        = new_current_length;
    GET_PROPERTY_FROM(idx2, buffer_arr, particle_var::l_max) = l_max_m;
  }
 
} // namespace Models
 
#endif