Local variables

! Local variables
 
integer          ifac, iel, ii
integer          inod
integer          ilelt, nlelt
 
double precision delta, deltaa
 
integer, allocatable, dimension(:) :: lstelt

Initialization and finalization

The following initialization block needs to be added for the following examples:

! Allocate a temporary array for boundary faces selection

allocate(lstelt(nfabor))

At the end of the subroutine, it is recommended to deallocate the work array:

! Deallocate the temporary array
deallocate(lstelt)
 

In theory Fortran 95 deallocates locally-allocated arrays automatically, but deallocating arrays in a symetric manner to their allocation is good pratice, and avoids using a different logic C and Fortran.

Assign boundary conditions to boundary faces

One may use selection criteria to filter boundary case subsets.
Loop on faces from a subset.
Set the boundary condition for each face.

Calculation of displacement at current time step

deltaa = sin(3.141596d0*(ntcabs-1)/50.d0)

delta = sin(3.141596d0*ntcabs/50.d0)

Example 1

Example : For boundary faces of color 4 assign a fixed velocity

 
call getfbr('4', nlelt, lstelt)
!==========
 
do ilelt = 1, nlelt
 
  ifac = lstelt(ilelt)
  ! Element adjacent a la face de bord
  iel = ifabor(ifac)
 
  ialtyb(ifac) = ivimpo
  rcodcl(ifac,iuma,1) = 0.d0
  rcodcl(ifac,ivma,1) = 0.d0
  rcodcl(ifac,iwma,1) = (delta-deltaa)/dt(iel)
 
enddo
 

Example 2

Example: For boundary face of color 5 assign a fixed displacement on nodes

 
call getfbr('5', nlelt, lstelt)
!==========
 
do ilelt = 1, nlelt
 
  ifac = lstelt(ilelt)
 
  do ii = ipnfbr(ifac), ipnfbr(ifac+1)-1
    inod = nodfbr(ii)
    if (impale(inod).eq.0) then
      disale(1,inod) = 0.d0
      disale(2,inod) = 0.d0
      disale(3,inod) = delta
      impale(inod) = 1
    endif
  enddo
 
enddo
 

Example 3

Example : For boundary faces of color 6 assign a sliding boundary

 
call getfbr('6', nlelt, lstelt)
!==========
 
do ilelt = 1, nlelt
 
  ifac = lstelt(ilelt)
 
  ialtyb(ifac) = igliss
 
enddo

Example 4

Example : Prescribe elsewhere a fixed boundary

 
call getfbr('not (4 or 5 or 6)', nlelt, lstelt)
!==========
 
do ilelt = 1, nlelt
 
  ifac = lstelt(ilelt)
 
  ialtyb(ifac) = ibfixe
 
enddo