[Nek5000-users] **ERROR**: Failed in HMHOLTZ

[nek5000-users at lists.mcs.anl.gov]

Here my usr-file. For some tests I'm using a fixed driving force ffz 
and calculate my u_bar in every timestep (subroutine calc_ubar).

The calculation also works if I'm only setting p94 to zero (projection 
of the velocity)...

What do you mean by "what happens if you integrate for say 1 
flow-through time"??


C-----------------------------------------------------------------------
C  nek5000 user-file template
C
C  user specified routines:
C     - userbc : boundary conditions
C     - useric : initial conditions
C     - uservp : variable properties
C     - userf  : local acceleration term for fluid
C     - userq  : local source term for scalars
C     - userchk: general purpose routine for checking errors etc.
C
C-----------------------------------------------------------------------
      subroutine uservp (ix,iy,iz,eg)
      include 'SIZE'
      include 'TOTAL'
      include 'NEKUSE'

      integer e,f,eg
c     e = gllel(eg)

      udiff  = 0.0
      utrans = 0.0

      return
      end
c-----------------------------------------------------------------------
      subroutine userf  (ix,iy,iz,eg)
c
c     Note: this is an acceleration term, NOT a force!
c     Thus, ffx will subsequently be multiplied by rho(x,t).
c
      include 'SIZE'
      include 'TOTAL'
      include 'NEKUSE'

      integer e,f,eg
c     e = gllel(eg)

      ffx = 0.0
      ffy = 0.0
      ffz = 0.05

      return
      end
c-----------------------------------------------------------------------
      subroutine userq  (ix,iy,iz,eg)
      include 'SIZE'
      include 'TOTAL'
      include 'NEKUSE'

      integer e,f,eg
c     e = gllel(eg)

      qvol   = 0.0
      source = 0.0

      return
      end
c-----------------------------------------------------------------------
      subroutine userchk
      include 'SIZE'
      include 'TOTAL'
      include 'ZPER'  ! for nelx,nely,nelz

      call calc_ubar(vz,1.0)

      return
      end
c-----------------------------------------------------------------------
      subroutine userbc (ix,iy,iz,iside,ieg)
      include 'SIZE'
      include 'TOTAL'
      include 'NEKUSE'

      ux   = 0.0
      uy   = 0.0
      uz   = 0.0
      temp = 0.0

      return
      end
c-----------------------------------------------------------------------
      subroutine useric (ix,iy,iz,ieg)
      include 'SIZE'
      include 'TOTAL'
      include 'NEKUSE'

      ux   = 0.0
      uy   = 0.0
      uz   = (1-(y-0.5)**2)
      temp = 0.0

      return
      end
c-----------------------------------------------------------------------
      subroutine usrdat   ! This routine to modify element vertices
      include 'SIZE'
      include 'TOTAL'

      return
      end
c-----------------------------------------------------------------------
      subroutine usrdat2  ! This routine to modify mesh coordinates
      include 'SIZE'
      include 'TOTAL'

      return
      end
c-----------------------------------------------------------------------
      subroutine usrdat3
      include 'SIZE'
      include 'TOTAL'

      return
      end
c-----------------------------------------------------------------------
      subroutine calc_ubar(u,idir)  ! driving force for Ubar = 1

      include 'SIZE'
      include 'TOTAL'

      common /uforce/ utldo(ldim)

      n=nx1*ny1*nz1*nelv

      if (istep.eq.0) f_new=param(71)  ! Update forcing for Ubar = 2

      ubar    = glsc2(u,bm1,n)/volvm1

      open(unit=10,file='u_bar.out')
      write(10,*) ubar,ISTEP,TIME

      return
      end