!-------------------------------------------------------------------------------

!                      Code_Saturne version 2.0.4n!                      --------------------------

!     This file is part of the Code_Saturne Kernel, element of the
!     Code_Saturne CFD tool.

!     Copyright (C) 1998-2008 EDF S.A., France

!     contact: saturne-support@edf.fr

!     The Code_Saturne Kernel is free software; you can redistribute it
!     and/or modify it under the terms of the GNU General Public License
!     as published by the Free Software Foundation; either version 2 of
!     the License, or (at your option) any later version.

!     The Code_Saturne Kernel is distributed in the hope that it will be
!     useful, but WITHOUT ANY WARRANTY; without even the implied warranty
!     of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
!     GNU General Public License for more details.

!     You should have received a copy of the GNU General Public License
!     along with the Code_Saturne Kernel; if not, write to the
!     Free Software Foundation, Inc.,
!     51 Franklin St, Fifth Floor,
!     Boston, MA  02110-1301  USA

!-------------------------------------------------------------------------------
!-------------------------------------------------------------------------------
subroutine usaste &
!================

 ( idbia0 , idbra0 ,                                              &
   ndim   , ncelet , ncel   , nfac   , nfabor , nfml   , nprfml , &
   nnod   , lndfac , lndfbr , ncelbr ,                            &
   nideve , nrdeve , nituse , nrtuse ,                            &
   ifacel , ifabor , ifmfbr , ifmcel , iprfml , maxelt , lstelt , &
   ipnfac , nodfac , ipnfbr , nodfbr , idfstr ,                   &
   idevel , ituser , ia     ,                                     &
   xyzcen , surfac , surfbo , cdgfac , cdgfbo , xyznod , volume , &
   rdevel , rtuser , ra     )



!===============================================================================
! Purpose:
! -------

!    User subroutine dedicated the Fluid-Structure external coupling
!    with Code_Aster :
!          Here one defines the boundary faces coupled
!          with Code_Aster and the fluid forces components
!          which are given to structural calculations

!    Boundary faces identification
!    =============================

!    Boundary faces may be identified using the 'getfbr' subroutine.
!    The syntax of this subroutine is described in the 'usclim' subroutine,
!    but a more thorough description can be found in the user guide.

!-------------------------------------------------------------------------------
! Arguments
!__________________.____._____.________________________________________________.
! name             !type!mode ! role                                           !
!__________________!____!_____!________________________________________________!
! idbia0           ! i  ! <-- ! number of first free position in ia            !
! idbra0           ! i  ! <-- ! number of first free position in ra            !
! ndim             ! i  ! <-- ! spatial dimension                              !
! ncelet           ! i  ! <-- ! number of extended (real + ghost) cells        !
! ncel             ! i  ! <-- ! number of cells                                !
! nfac             ! i  ! <-- ! number of interior faces                       !
! nfabor           ! i  ! <-- ! number of boundary faces                       !
! nfml             ! i  ! <-- ! number of families (group classes)             !
! nprfml           ! i  ! <-- ! number of properties per family (group class)  !
! nnod             ! i  ! <-- ! number of vertices                             !
! lndfac           ! i  ! <-- ! size of nodfac indexed array                   !
! lndfbr           ! i  ! <-- ! size of nodfbr indexed array                   !
! ncelbr           ! i  ! <-- ! number of cells with faces on boundary         !
! nideve, nrdeve   ! i  ! <-- ! sizes of idevel and rdevel arrays              !
! nituse, nrtuse   ! i  ! <-- ! sizes of ituser and rtuser arrays              !
! ifacel(2, nfac)  ! ia ! <-- ! interior faces -> cells connectivity           !
! ifabor(nfabor)   ! ia ! <-- ! boundary faces -> cells connectivity           !
! ifmfbr(nfabor)   ! ia ! <-- ! boundary face family numbers                   !
! ifmcel(ncelet)   ! ia ! <-- ! cell family numbers                            !
! iprfml           ! ia ! <-- ! property numbers per family                    !
!  (nfml, nprfml)  !    !     !                                                !
! maxelt           ! i  ! <-- ! max number of cells and faces (int/boundary)   !
! lstelt(maxelt)   ! ia ! --- ! work array                                     !
! ipnfac(nfac+1)   ! ia ! <-- ! interior faces -> vertices index (optional)    !
! nodfac(lndfac)   ! ia ! <-- ! interior faces -> vertices list (optional)     !
! ipnfbr(nfabor+1) ! ia ! <-- ! boundary faces -> vertices index (optional)    !
! nodfbr(lndfbr)   ! ia ! <-- ! boundary faces -> vertices list (optional)     !
! idfstr(nfabor)   ! ia ! <-- ! boundary faces -> structure definition         !
! idevel(nideve)   ! ia ! <-- ! integer work array for temporary development   !
! ituser(nituse)   ! ia ! <-- ! user-reserved integer work array               !
! ia(*)            ! ia ! --- ! main integer work array                        !
! xyzcen           ! ra ! <-- ! cell centers                                   !
!  (ndim, ncelet)  !    !     !                                                !
! surfac           ! ra ! <-- ! interior faces surface vectors                 !
!  (ndim, nfac)    !    !     !                                                !
! surfbo           ! ra ! <-- ! boundary faces surface vectors                 !
!  (ndim, nfabor)  !    !     !                                                !
! cdgfac           ! ra ! <-- ! interior faces centers of gravity              !
!  (ndim, nfac)    !    !     !                                                !
! cdgfbo           ! ra ! <-- ! boundary faces centers of gravity              !
!  (ndim, nfabor)  !    !     !                                                !
! xyznod           ! ra ! <-- ! vertex coordinates (optional)                  !
!  (ndim, nnod)    !    !     !                                                !
! volume(ncelet)   ! ra ! <-- ! cell volumes                                   !
! rdevel(nrdeve)   ! ra ! <-> ! real work array for temporary development      !
! rtuser(nrtuse)   ! ra ! <-- ! user-reserved real work array                  !
! ra(*)            ! ra ! --- ! main real work array                           !
!__________________!____!_____!________________________________________________!

!     Type: i (integer), r (real), s (string), a (array), l (logical),
!           and composite types (ex: ra real array)
!     mode: <-- input, --> output, <-> modifies data, --- work array
!===============================================================================

implicit none

!===============================================================================
! Common blocks
!===============================================================================

include "paramx.h"
include "cstnum.h"
include "optcal.h"
include "entsor.h"
include "pointe.h"
include "albase.h"
include "period.h"
include "parall.h"
include "alaste.h"

!===============================================================================

! Arguments

integer          idbia0 , idbra0
integer          ndim   , ncelet , ncel   , nfac   , nfabor
integer          nfml   , nprfml
integer          nnod   , lndfac , lndfbr , ncelbr
integer          nbstru
integer          nideve , nrdeve , nituse , nrtuse

integer          ifacel(2,nfac) , ifabor(nfabor)
integer          ifmfbr(nfabor) , ifmcel(ncelet)
integer          iprfml(nfml,nprfml)
integer          maxelt, lstelt(maxelt)
integer          ipnfac(nfac+1), nodfac(lndfac)
integer          ipnfbr(nfabor+1), nodfbr(lndfbr)
integer          idfstr(nfabor)
integer          idevel(nideve), ituser(nituse)
integer          ia(*)

double precision xyzcen(ndim,ncelet)
double precision surfac(ndim,nfac), surfbo(ndim,nfabor)
double precision cdgfac(ndim,nfac), cdgfbo(ndim,nfabor)
double precision xyznod(ndim,nnod), volume(ncelet)
double precision rdevel(nrdeve), rtuser(nrtuse), ra(*)

! Local variables

integer          idebia, idebra
integer          ifac
integer          ilelt, nlelt

!===============================================================================

!===============================================================================
! 1.  INITIALIZATION

!===============================================================================

idebia = idbia0
idebra = idbra0

!===============================================================================
! 2.  Definition of external structures
!===============================================================================

!    Here one fills array IDFSTR(NFABOR)
!    For each boundary face IFAC, IDFSTR(IFAC) is the number of the structure
!    the face belongs to (if IDFSTR(IFAC) = 0, the face IFAC doesn't
!    belong to any structure.)
!    When using external coupling with Code_Aster, structure number necessarily
!    needs to be negative (as shown in following examples).

!    The number of "external" structures with Code Aster is automatically
!    defined with the maximum absolute value of IDFSTR table, meaning that
!    external structure numbers must be defined sequentially with negative values
!    beginning with integer value '-1'.


!    In following example, boundary faces with color 2 and which abscissa X < 2.0
!    belong to external structure '-1'.
!    Boundary faces with color 2 and which abscissa X > 2.0 belong to external
!    structure '-2'. The total number of external structures coupled with Code_Aster
!    equals 2.

!    Boundary faces identification
!    =============================

!    Boundary faces may be identified using the 'getfbr' subroutine.
!    The syntax of this subroutine is described in the 'usclim' subroutine,
!    but a more thorough description can be found in the user guide.

!================================================================================

CALL GETFBR('2 and X < 2.0',NLELT,LSTELT)
!==========

do ilelt = 1, nlelt

  ifac = lstelt(ilelt)

  idfstr(ifac) = -1

enddo


CALL GETFBR('2 and X > 2.0',NLELT,LSTELT)
!==========

do ilelt = 1, nlelt

  ifac = lstelt(ilelt)

  idfstr(ifac) = -2

enddo

! --- The movement of external structure called '-1' is blocked in Z direction.

asddlf(3,1) = 0

! --- The movement of external structure called '-2' is blocked in Z direction.

asddlf(3,2) = 0

! --- Activation of Code_Saturne/Code_Aster synchronized chronological output.
!     (ISYNCP = 1 : Synchronized output, ISYNCP = 0: Non synchronized output)

isyncp = 1

!----
! Formats
!----

!----
! End
!----
return

