adjoint_scalar_convection_source_term.f90

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! this is a such a dumb name
module adjoint_scalar_convection_source_term
  use num_types, only: rp
  use field_list, only: field_list_t
  use field, only: field_t
  use scratch_registry, only: neko_scratch_registry
  use json_module, only: json_file
  use source_term, only: source_term_t
  use coefs, only: coef_t
  use field_math, only: field_subcol3
  use operators, only: grad
  implicit none
  private
 
  ! I don't know how to name this term, but when you have a passive
  ! scalar you get an extra term in the adjoint velocity equation, which comes
  ! from the convective term in the passive scalar equation.
  ! Maybe this should be called just `adjoint_scalar_convection`?
  ! but it does come in a source term...
 
  ! In any case,
  ! it's a source term acting on the adjoint velocity equations, of the form:
  ! \f$\nabla s s_adj\f$
  type, public, extends(source_term_t) :: &
       adjoint_scalar_convection_source_term_t
     type(field_t), pointer :: s_adj => null()
     type(field_t), pointer :: s => null()
   contains
     procedure, pass(this) :: init => &
          adjoint_scalar_convection_source_term_init_from_json
     procedure, pass(this) :: init_from_components => &
          adjoint_scalar_convection_source_term_init_from_components
     procedure, pass(this) :: free => adjoint_scalar_convection_source_term_free
     procedure, pass(this) :: compute_ => &
          adjoint_scalar_convection_source_term_compute
  end type adjoint_scalar_convection_source_term_t
 
contains
  subroutine adjoint_scalar_convection_source_term_init_from_json(this, &
       json, fields, coef, variable_name)
    class(adjoint_scalar_convection_source_term_t), intent(inout) :: this
    type(json_file), intent(inout) :: json
    type(field_list_t), intent(in), target :: fields
    type(coef_t), intent(in), target :: coef
    character(len=*), intent(in) :: variable_name
 
    ! this is a bit weird... because I don't think this should come from the
    ! JSON.
    ! Maybe we should think of all these source terms as only "appendable"
    !
    ! Because we'll never have the whole case here, so we'll never be able
    ! init from components anyway...
 
 
  end subroutine adjoint_scalar_convection_source_term_init_from_json
 
 
  subroutine adjoint_scalar_convection_source_term_init_from_components(this,&
       f_x, f_y, f_z, s, s_adj, coef)
    class(adjoint_scalar_convection_source_term_t), intent(inout) :: this
    type(field_t), pointer, intent(in) :: f_x, f_y, f_z
    type(field_list_t) :: fields
    type(coef_t) :: coef
    real(kind=rp) :: start_time
    real(kind=rp) :: end_time
    type(field_t), intent(in), target :: s, s_adj
 
    ! I wish you didn't need a start time and end time...
    ! but I'm just going to set a super big number...
    start_time = 0.0_rp
    end_time = 100000000.0_rp
 
    call this%free()
 
    ! this is copying the fluid source term init
    ! We package the fields for the source term to operate on in a field list.
    call fields%init(3)
    call fields%assign(1, f_x)
    call fields%assign(2, f_y)
    call fields%assign(3, f_z)
 
    call this%init_base(fields, coef, start_time, end_time)
 
    ! point everything in the correct places
    this%s_adj => s_adj
    this%s => s
 
  end subroutine adjoint_scalar_convection_source_term_init_from_components
 
  subroutine adjoint_scalar_convection_source_term_free(this)
    class(adjoint_scalar_convection_source_term_t), intent(inout) :: this
 
    call this%free_base()
  end subroutine adjoint_scalar_convection_source_term_free
 
  subroutine adjoint_scalar_convection_source_term_compute(this, t, tstep)
    class(adjoint_scalar_convection_source_term_t), intent(inout) :: this
    real(kind=rp), intent(in) :: t
    integer, intent(in) :: tstep
    type(field_t), pointer :: fu, fv, fw
    integer :: temp_indices(3)
    type(field_t), pointer :: dsdx, dsdy, dsdz
 
 
    call neko_scratch_registry%request_field(dsdx, temp_indices(1))
    call neko_scratch_registry%request_field(dsdy, temp_indices(2))
    call neko_scratch_registry%request_field(dsdz, temp_indices(3))
 
    fu => this%fields%get(1)
    fv => this%fields%get(2)
    fw => this%fields%get(3)
 
    ! we basically just need the term
    ! \f$\nabla s s_adj\f$
    ! TODO
    ! In principle, this should have to option to be evaluated on the dealiased
    ! mesh!
 
    ! So should the Brinkman term actually....
 
    call grad(dsdx%x, dsdy%x, dsdz%x, this%s%x, this%coef)
 
    ! TODO
    ! So in principal, the derivatives could have kinks now.
    ! I don't think a gsop will remedy this (or even whether it's a good idea)
    ! But I want to leave this todo as a reminder.
 
    call field_subcol3(fu, this%s_adj, dsdx)
    call field_subcol3(fv, this%s_adj, dsdy)
    call field_subcol3(fw, this%s_adj, dsdz)
 
    ! free the scratch
    call neko_scratch_registry%relinquish_field(temp_indices)
  end subroutine adjoint_scalar_convection_source_term_compute
 
end module adjoint_scalar_convection_source_term