compute_step_health Subroutine

   subroutine compute_step_health(mesh, flow, params, fields, transport, kinetic_energy, cfl_value, max_velocity)
      type(mesh_t), intent(in) :: mesh
      type(flow_mpi_t), intent(in) :: flow
      type(case_params_t), intent(in) :: params
      type(flow_fields_t), intent(in) :: fields
      type(transport_properties_t), intent(in) :: transport
      real(rk), intent(out) :: kinetic_energy
      real(rk), intent(out) :: cfl_value
      real(rk), intent(out) :: max_velocity

      integer :: c, lf, f, ierr
      real(rk) :: rho_cell, vmag, local_ke, global_ke
      real(rk) :: local_umax, global_umax
      real(rk) :: local_cfl_rate, global_cfl_rate, cell_outward_flux

      local_ke = zero
      local_umax = zero
      local_cfl_rate = zero

      do c = flow%first_cell, flow%last_cell
         rho_cell = params%rho
         if (params%enable_variable_density .and. allocated(transport%rho)) then
            if (c <= size(transport%rho)) rho_cell = max(transport%rho(c), tiny_safe)
         end if
         vmag = sqrt(dot_product(fields%u(:, c), fields%u(:, c)))
         local_umax = max(local_umax, vmag)
         local_ke = local_ke + 0.5_rk * rho_cell * mesh%cells(c)%volume * vmag * vmag

         if (allocated(fields%face_flux)) then
            cell_outward_flux = zero
            do lf = 1, mesh%ncell_faces(c)
               f = mesh%cell_faces(lf, c)
               cell_outward_flux = cell_outward_flux + abs(fields%face_flux(f))
            end do
            if (mesh%cells(c)%volume > tiny_safe) then
               local_cfl_rate = max(local_cfl_rate, 0.5_rk * cell_outward_flux / mesh%cells(c)%volume)
            end if
         end if
      end do

      call MPI_Allreduce(local_ke, global_ke, 1, MPI_DOUBLE_PRECISION, MPI_SUM, flow%comm, ierr)
      if (ierr /= MPI_SUCCESS) call fatal_error('main', 'MPI failure reducing step kinetic energy')
      call MPI_Allreduce(local_umax, global_umax, 1, MPI_DOUBLE_PRECISION, MPI_MAX, flow%comm, ierr)
      if (ierr /= MPI_SUCCESS) call fatal_error('main', 'MPI failure reducing step max velocity')
      call MPI_Allreduce(local_cfl_rate, global_cfl_rate, 1, MPI_DOUBLE_PRECISION, MPI_MAX, flow%comm, ierr)
      if (ierr /= MPI_SUCCESS) call fatal_error('main', 'MPI failure reducing step CFL rate')

      kinetic_energy = global_ke
      max_velocity = global_umax
      cfl_value = global_cfl_rate * params%dt
   end subroutine compute_step_health