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

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

!     Copyright (C) 1998-2009 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 cfdttv &
!================

 ( idbia0 , idbra0 ,                                              &
   ndim   , ncelet , ncel   , nfac   , nfabor , nfml   , nprfml , &
   nnod   , lndfac , lndfbr , ncelbr ,                            &
   nvar   , nscal  , nphas  , ncepdp , ncesmp ,                   &
   nideve , nrdeve , nituse , nrtuse , iwarnp ,                   &
   ifacel , ifabor , ifmfbr , ifmcel , iprfml ,                   &
   ipnfac , nodfac , ipnfbr , nodfbr ,                            &
   icepdc , icetsm , itypsm ,                                     &
   idevel , ituser , ia     ,                                     &
   xyzcen , surfac , surfbo , cdgfac , cdgfbo , xyznod , volume , &
   dt     , rtp    , rtpa   , propce , propfa , propfb ,          &
   coefa  , coefb  , ckupdc , smacel ,                            &
   wcf    ,                                                       &
   wflmas , wflmab , viscb  , w1     , w2     , w3     ,          &
   w4     , w5     , w6     ,                                     &
   rdevel , rtuser , ra     )

!===============================================================================
! FONCTION :
! ----------

! CALCUL DE LA CONTRAINTE LIEE AU CFL POUR L'ALGO COMPRESSIBLE

!-------------------------------------------------------------------------------
! 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         !
! nvar             ! i  ! <-- ! total number of variables                      !
! nscal            ! i  ! <-- ! total number of scalars                        !
! nphas            ! i  ! <-- ! number of phases                               !
! ncepdp           ! i  ! <-- ! number of cells with head loss                 !
! ncesmp           ! i  ! <-- ! number of cells with mass source term          !
! nideve, nrdeve   ! i  ! <-- ! sizes of idevel and rdevel arrays              !
! nituse, nrtuse   ! i  ! <-- ! sizes of ituser and rtuser arrays              !
! iwarnp           ! i  ! <-- ! verbosity                                      !
! 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)  !    !     !                                                !
! 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)     !
! icepdc(ncelet    ! te ! <-- ! numero des ncepdp cellules avec pdc            !
! icetsm(ncesmp    ! te ! <-- ! numero des cellules a source de masse          !
! itypsm           ! te ! <-- ! type de source de masse pour les               !
! (ncesmp,nvar)    !    !     !  variables (cf. ustsma)                        !
! 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                                   !
! dt(ncelet)       ! ra ! <-- ! time step (per cell)                           !
! rtp, rtpa        ! ra ! <-- ! calculated variables at cell centers           !
!  (ncelet, *)     !    !     !  (at current and previous time steps)          !
! propce(ncelet, *)! ra ! <-- ! physical properties at cell centers            !
! propfa(nfac, *)  ! ra ! <-- ! physical properties at interior face centers   !
! propfb(nfabor, *)! ra ! <-- ! physical properties at boundary face centers   !
! coefa, coefb     ! ra ! <-- ! boundary conditions                            !
!  (nfabor, *)     !    !     !                                                !
! ckupdc           ! tr ! <-- ! tableau de travail pour pdc                    !
!  (ncepdp,6)      !    !     !                                                !
! smacel           ! tr ! <-- ! valeur des variables associee a la             !
! (ncesmp,nvar)    !    !     !  source de masse                               !
!                  !    !     ! pour ivar=ipr, smacel=flux de masse            !
! wcf(ncelet)      ! tr ! --> ! contrainte compressible                        !
! wflmas(nfac)     ! tr ! --- ! tab de trav aux faces internes                 !
! wflmab(nfabor    ! tr ! --- ! tab de trav aux faces de bord                  !
! viscb(nfabor     ! tr ! --- ! tab de trav aux faces de bord                  !
! w1..6 (ncelet    ! tr ! --- ! tableaux de travail                            !
! rdevel(nrdeve)   ! ra ! <-> ! real work array for temporary development      !
! rtuser(nrtuse)   ! ra ! <-> ! user-reserved real work array                  !
! ra(*)            ! ra ! --- ! main real work array                           !
!__________________!____!_____!________________________________________________!

!     TYPE : E (ENTIER), R (REEL), A (ALPHANUMERIQUE), T (TABLEAU)
!            L (LOGIQUE)   .. ET TYPES COMPOSES (EX : TR TABLEAU REEL)
!     MODE : <-- donnee, --> resultat, <-> Donnee modifiee
!            --- tableau de travail
!===============================================================================

implicit none

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

include "paramx.h"
include "numvar.h"
include "cstnum.h"
include "cstphy.h"
include "optcal.h"
include "entsor.h"
include "parall.h"
include "ppppar.h"
include "ppthch.h"
include "ppincl.h"

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

! Arguments

integer          idbia0 , idbra0
integer          ndim   , ncelet , ncel   , nfac   , nfabor
integer          nfml   , nprfml
integer          nnod   , lndfac , lndfbr , ncelbr
integer          nvar   , nscal  , nphas
integer          ncepdp , ncesmp
integer          nideve , nrdeve , nituse , nrtuse , iwarnp

integer          ifacel(2,nfac) , ifabor(nfabor)
integer          ifmfbr(nfabor) , ifmcel(ncelet)
integer          iprfml(nfml,nprfml)
integer          ipnfac(nfac+1), nodfac(lndfac)
integer          ipnfbr(nfabor+1), nodfbr(lndfbr)
integer          icepdc(ncepdp)
integer          icetsm(ncesmp), itypsm(ncesmp,nvar)
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 dt(ncelet), rtp(ncelet,*), rtpa(ncelet,*)
double precision propce(ncelet,*)
double precision propfa(nfac,*), propfb(nfabor,*)
double precision coefa(nfabor,*), coefb(nfabor,*)
double precision ckupdc(ncepdp,6), smacel(ncesmp,nvar)
double precision wcf(ncelet)
double precision wflmas(nfac), wflmab(nfabor), viscb(nfabor)
double precision w1(ncelet), w2(ncelet), w3(ncelet)
double precision w4(ncelet), w5(ncelet), w6(ncelet)
double precision rdevel(nrdeve), rtuser(nrtuse), ra(*)

! Local variables

integer          idebia, idebra, ifinia, ifinra
integer          ifac  , iel   , iphas , ivar  , iscal
integer          init
integer          iw7   , iw8   , iw9   , iw10  , iw11  , iw12
integer          iviscf, icoefu, ixam

!===============================================================================
!===============================================================================
! 0.  INITIALISATION
!===============================================================================

idebia = idbia0
idebra = idbra0

iphas   = 1

iscal  = irho(iphas)
ivar   = isca(iscal)

!===============================================================================
! 1. MEMOIRE
!===============================================================================

call memcft                                                       &
!==========
 ( idebia , idebra ,                                              &
   ndim   , ncelet , ncel   , nfac   , nfabor , nfml   , nprfml , &
   nnod   , lndfac , lndfbr , ncelbr ,                            &
   nvar   , nscal  , nphas  ,                                     &
   iw7    , iw8    , iw9    , iw10   , iw11   , iw12   ,          &
   iviscf , icoefu , ixam   ,                                     &
   ifinia , ifinra )

idebia = ifinia
idebra = ifinra

!===============================================================================
! 2. CALCUL DE LA CONDITION CFL ASSOCIEE A LA MASSE VOLUMIQUE
!===============================================================================

! ---> Calcul du "flux de masse" associe a la masse volumique

do ifac = 1, nfac
  wflmas(ifac) = 0.d0
enddo
do ifac = 1, nfabor
  wflmab(ifac) = 0.d0
enddo

call cfmsfl                                                       &
!==========
 ( idebia , idebra ,                                              &
   ndim   , ncelet , ncel   , nfac   , nfabor , nfml   , nprfml , &
   nnod   , lndfac , lndfbr , ncelbr ,                            &
   nvar   , nscal  , nphas  , ncepdp , ncesmp ,                   &
   nideve , nrdeve , nituse , nrtuse , iscal  ,                   &
   ifacel , ifabor , ifmfbr , ifmcel , iprfml ,                   &
   ipnfac , nodfac , ipnfbr , nodfbr ,                            &
   icepdc , icetsm , itypsm ,                                     &
   idevel , ituser , ia     ,                                     &
   xyzcen , surfac , surfbo , cdgfac , cdgfbo , xyznod , volume , &
   dt     , rtp    , rtpa   , propce , propfa , propfb ,          &
   coefa  , coefb  , ckupdc , smacel ,                            &
   wflmas , wflmab ,                                              &
   w1     , w2     , w3     , w4     , w5     , w6     ,          &
   ra(iw7), ra(iw8), ra(iw9), ra(iw10) , ra(iw11) , ra(iw12) ,    &
   ra(iviscf) , viscb , ra(icoefu) , ra(ixam) ,                   &
   rdevel , rtuser ,                                              &
   ra     )

! ---> Sommation sur les faces (depend de si l'on explicite ou non
!                               le terme de convection)

init = 1
call divmas(ncelet,ncel,nfac,nfabor,init,nfecra,                  &
               ifacel,ifabor,wflmas,wflmab,w1)

do ifac = 1, nfac
  wflmas(ifac) = max(0.d0,wflmas(ifac))
enddo
do ifac = 1, nfabor
  wflmab(ifac) = max(0.d0,wflmab(ifac))
enddo
call divmas(ncelet,ncel,nfac,nfabor,init,nfecra,                  &
               ifacel,ifabor,wflmas,wflmab,w2)


! ---> Calcul du coefficient CFL/Dt

do iel = 1, ncel
  wcf(iel) = max( -dble(iconv(ivar))*w1(iel)/volume(iel),         &
       max( dble(1-iconv(ivar))*w2(iel)/volume(iel), 0.d0 ) )
enddo

!--------
! FORMATS
!--------

!----
! FIN
!----

return

end subroutine
