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

!                      Code_Saturne version 4.0.2
!                      --------------------------
! This file is part of Code_Saturne, a general-purpose CFD tool.
!
! Copyright (C) 1998-2015 EDF S.A.
!
! This program 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.
!
! This program 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
! this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
! Street, Fifth Floor, Boston, MA 02110-1301, USA.

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

!===============================================================================
! Function:
! ---------

!> \file cs_user_boundary_conditions.f90
!>
!> \brief User subroutine which fills boundary conditions arrays
!> (\c icodcl, \c rcodcl) for unknown variables.
!>
!>
!-------------------------------------------------------------------------------
! Arguments
!______________________________________________________________________________.
!  mode           name          role                                           !
!______________________________________________________________________________!
!> \param[in]     nvar          total number of variables
!> \param[in]     nscal         total number of scalars
!> \param[out]    icodcl        boundary condition code:
!>                               - 1 Dirichlet
!>                               - 2 Radiative outlet
!>                               - 3 Neumann
!>                               - 4 sliding and
!>                                 \f$ \vect{u} \cdot \vect{n} = 0 \f$
!>                               - 5 smooth wall and
!>                                 \f$ \vect{u} \cdot \vect{n} = 0 \f$
!>                               - 6 rough wall and
!>                                 \f$ \vect{u} \cdot \vect{n} = 0 \f$
!>                               - 9 free inlet/outlet
!>                                 (input mass flux blocked to 0)
!>                               - 13 Dirichlet for the advection operator and
!>                                    Neumann for the diffusion operator
!> \param[in]     itrifb        indirection for boundary faces ordering
!> \param[in,out] itypfb        boundary face types
!> \param[out]    izfppp        boundary face zone number
!> \param[in]     dt            time step (per cell)
!> \param[in,out] rcodcl        boundary condition values:
!>                               - rcodcl(1) value of the dirichlet
!>                               - rcodcl(2) value of the exterior exchange
!>                                 coefficient (infinite if no exchange)
!>                               - rcodcl(3) value flux density
!>                                 (negative if gain) in w/m2 or roughness
!>                                 in m if icodcl=6
!>                                 -# for the velocity \f$ (\mu+\mu_T)
!>                                    \gradt \, \vect{u} \cdot \vect{n}  \f$
!>                                 -# for the pressure \f$ \Delta t
!>                                    \grad P \cdot \vect{n}  \f$
!>                                 -# for a scalar \f$ cp \left( K +
!>                                     \dfrac{K_T}{\sigma_T} \right)
!>                                     \grad T \cdot \vect{n} \f$
!_______________________________________________________________________________

subroutine cs_user_boundary_conditions &
 ( nvar   , nscal  ,                                              &
   icodcl , itrifb , itypfb , izfppp ,                            &
   dt     ,                                                       &
   rcodcl )

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

!===============================================================================
! Module files
!===============================================================================

use paramx
use numvar
use optcal
use cstphy
use cstnum
use entsor
use parall
use period
use ihmpre
use ppppar
use ppthch
use coincl
use cpincl
use ppincl
use ppcpfu
use atincl
use atsoil
use ctincl
use elincl
use cs_fuel_incl
use mesh
use field
use turbomachinery
use iso_c_binding
use cs_c_bindings

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

implicit none

! Arguments

integer          ifac, nvar, nscal, ilelt, nlelt

integer          icodcl(nfabor,nvarcl)
integer          itrifb(nfabor), itypfb(nfabor)
integer          izfppp(nfabor)

double precision dt(ncelet)
double precision rcodcl(nfabor,nvarcl,3)
double precision xnod(3), norm_u, norm_x1, u(3), x1(3)
double precision ang, mb, d, omegap, vtan


integer, allocatable, dimension(:) :: lstelt

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

!===============================================================================
! Initialization
!===============================================================================

allocate(lstelt(nfabor))  ! temporary array for boundary faces selection


   call getfbr('Object', nlelt, lstelt)

!Angle of attack [deg]
ang=10.0d0
mb=tan(ang*3.14159/180)
!Rotation direction
u(1)=1
u(2)=0
u(3)=mb
norm_u = sqrt(u(1)**2+u(2)**2+u(3)**2)
!Veloc rotation [rad/s]
omegap=3.866
   
  do ilelt = 1, nlelt

   ifac = lstelt(ilelt)

   itypfb(ifac)   = iparoi

   xnod(1) = cdgfbo(1, ifac)
   xnod(2) = cdgfbo(2, ifac)
   xnod(3) = cdgfbo(3, ifac)
! x1 = Normal to the plano P X U (To impose tangencial vel)   
   x1(1) = xnod(2)*u(3)
   x1(2) = -(xnod(1)*u(3)- xnod(3)*u(1))
   x1(3) = -xnod(2)*u(1)
   norm_x1 = sqrt(x1(1)**2 + x1(2)**2 + x1(3)**2)
   ! Distance to the rotation axis
   d=norm_x1/norm_u
   ! Tang veloc
   vtan=omegap*d
   
   icodcl(ifac,iu )  = 5
   rcodcl(ifac,iu,1) = vtan*(x1(1)/norm_x1)
   icodcl(ifac,iv )  = 5
   rcodcl(ifac,iv,1) = vtan*(x1(2)/norm_x1)
   icodcl(ifac,iw )  = 5
   rcodcl(ifac,iw,1) = vtan*(x1(3)/norm_x1)
  enddo

deallocate(lstelt)  ! temporary array for boundary faces selection

return
end subroutine cs_user_boundary_conditions