[Nek5000-users] WARNING: DIV(V)-QTL too large

nek5000-users at lists.mcs.anl.gov nek5000-users at lists.mcs.anl.gov
Tue Jan 12 07:43:58 CST 2016


dear developers ,

I'm doing a rotator-stator type of simulation using Pn-Pn method (lx1=8
lxd=12 ).  Annular mesh has been created using genbox (box file is
attached). Inner radius is considered as the hub and outer radius is the
case (or the sidewalls of the disk ). I use following settings  in rea file

3                     p27  TORDER
20.00000         p93 Number of prev pressure solns saved
5.000000         p94 start projecting vel. after p94 step
5.000000         p95 start projecting pr after p95 step
4.000000         p99    dealiasing:if <0 disable
1.000000         p101   No. of additional filter modes
 5.000000E-02     p103   weight of stabilizing filter (.01)

Hub and rotor (z=0) rotating in a constant angular velocity. Stator (z=0.2)
and side walls are stationary. singularities among rotor and stationary
components are resolved using a method which is very similar to vortex
example (using an exponential ramp instead of a polynomial ramp) .  After
3000-4000 iterations , CFL number reached around 0.48 and I got following
warning


               L1/L2 DIV(V)    :  -1.6903E-16   1.0198E-01
               L1/L2 QTL       :   0.0000E+00   0.0000E+00
               L1/L2 DIV(V)-QTL:  -1.6903E-16   1.0198E-01
               WARNING: DIV(V)-QTL too large!

I'm not using any inlets or outlets in my simulation. I'm not sure the
reason for this warning.  can anybody give me a little advice regarding
this situation.  I can provide more details on request.


Desanga
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/nek5000-users/attachments/20160112/aaaa0a53/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 3da.box
Type: application/octet-stream
Size: 1363 bytes
Desc: not available
URL: <http://lists.mcs.anl.gov/pipermail/nek5000-users/attachments/20160112/aaaa0a53/attachment.obj>


More information about the Nek5000-users mailing list