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

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

You¹ll get a WARNING because the difference in divergence is quite large.
Is your simulation blowing up? I guess in your case it is related to
temporal/spatial resolution. Try to use a smaller time step and/or
increased resolution.

Cheers,
Stefan

Am 1/24/16, 1:43 AM schrieb "nek5000-users-bounces at lists.mcs.anl.gov on
behalf of nek5000-users at lists.mcs.anl.gov" unter
<nek5000-users-bounces at lists.mcs.anl.gov on behalf of
nek5000-users at lists.mcs.anl.gov>:

>dear neks,
>
>nobody is replying me???
>
>Thanks
>> On 12 Jan 2016, at 13:43, Desanga Fernando <desanga at gmail.com> wrote:
>> 
>> 
>> 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 
>>  
>> <3da.box>
>
>_______________________________________________
>Nek5000-users mailing list
>Nek5000-users at lists.mcs.anl.gov
>https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users