[Nek5000-users] Outflow divergence

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

Howdy neks,

I updated my divergence-for-outflow code from the latest repo of the jet 
example case (since I have a suspicion the old one is messing with my 
simulation upstream of the outflow) and found the following issue:
"
       if (ifsplit) then
          do i=1,ntot2
             dd = dist(i,1,1,1)*dist(i,1,1,1)
             dd = min(dmax2,dd)
             if (dist(i,1,1,1).ge.0) usrdiv(i,1,1,1) = cdiv*(1.-dd/dmax2)
             if (dist(i,1,1,1).ge.0) nd = nd+1
          enddo
"
This seems to add user divergence linearly in the outflow elements (from 
zero at the farthest distance from the outfow face to some value at it), 
which is intended, but also adds divergence everywhere else (dd&dist are 
zero in all non-outflow elements). This of course causes undesired 
acceleration in domain parts where I'd like to keep a constant flow 
rate, say.

Was the intention: "if (dist(i,1,1,1).gt.0) usrdiv(i,1,1,1) = 
cdiv*(1.-dd/dmax2)"?
How is "ifsplit true" treated differently from "false" in this regard?

Thanks,
Markus