[Nek5000-users] Replace velocity fields in perturbation mode

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

Hi Andrea,

Looking at SOLN, I see the following variables
that might also need attention:

PRLAGP

VGRADT1P, VGRADT2P

though the latter two seem to be related only to
thermal problems.

My guess is that it's the pressure lag that you're
missing, which would be consistent with the variance
in the TORDER behavior that you're reporting.

Paul



On Mon, 15 Oct 2012, nek5000-users at lists.mcs.anl.gov wrote:

> Hi Nek's,
>
> I am using Nek  in perturbation mode. At a certain time step i need to
> replace the velocity field with a different  one.
>
> In usrchk I replace (vxp,vyp,vzp) with my field (vxb,vyb,vzb). I also
> reset vxlagp,vylagp,vzlagp and the extrapolation terms exxp1,exyp1,exzp1
> and exxp2,exyp2,exzp2.
>
>               call opcopy(vxp,vyp,vzp,vxb,vyb,vzb)
>               call opzero(exx1p,exy1p,exz1p)
>               call opzero(exx2p,exy2p,exz2p)
>               do i=1,lorder-1
>                  call opzero(vxlagp(1,i,1),vylagp(1,i,1), vzlagp(1,i,1))
>               enddo
>
> It works well if I set Torder=1, but for Torder=2 it seems that there are
> data contamination from previous time steps, so I think I'm missing some
> variables which i need to modify.
>
> Andrea
>