Re: [Nektar-users] extracting isosurfaces on runtime

8 Mar 2017

      Hi Douglas,

thanks for the suggestion, it works this way. The solver writes out
partitioned vtu files.

However, isocontour module does not seem to work properly in parallel
unfortunately. This is also the case when I run it with FieldConvert
directly. The extracted data is some strange collection of triangular
surfaces. I attached a snapshot showing that.

Best,
Asim

On Tue, Mar 7, 2017 at 11:26 PM, Serson, Douglas <d.serson14@imperial.ac.uk>
wrote:
...
Hi Asim,
I am not sure if isocontours will work with this filter, but here are a
few things that could help you:
- You can specify more than one module in the "Modules" parameter, and
they will be executed in sequence.
- The parameters for each module should also be in "Modules",
separated by ":", e.g. isocontour:fieldstr=Q:fieldvalue=1000
- I think the isocontour module only works with .dat and .vtu outputs.
Considering this, you could try
<FILTER TYPE="FieldConvert">
       <PARAM NAME="OutputFile">Q_214_iso2000.vtu</PARAM>
       <PARAM NAME="OutputFrequency">10</PARAM>
       <PARAM NAME="Modules"> QCriterion isocontour:fieldvalue=1000:fieldid=4
</PARAM>
     </FILTER>
where you should check the correct fieldid for the Q field (it should be 4
for 3D simulations).
Cheers,
Douglas
------------------------------
*From:* nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@
imperial.ac.uk> on behalf of Asım Önder <asim.onder@gmail.com>
*Sent:* 07 March 2017 07:04:41
*To:* nektar-users
*Subject:* [Nektar-users] extracting isosurfaces on runtime
Dear all,
Is there any way to make isocontour module work in filter mode for derived
quantities, e.g., Q field?
I tried the following in config.xml file for a run using
IncNavierStokesSolver solver:
<FILTER TYPE="FieldConvert">
       <PARAM NAME="OutputFile">Q_214.fld</PARAM>
       <PARAM NAME="OutputFrequency">10</PARAM>
       <PARAM NAME="Modules"> QCriterion </PARAM>
     </FILTER>
<FILTER TYPE="FieldConvert">
       <PARAM NAME="OutputFile">Q_214_iso2000.fld</PARAM>
       <PARAM NAME="OutputFrequency">10</PARAM>
       <PARAM NAME="Modules"> isocontour </PARAM>
       <PARAM NAME="fieldstr"> Q </PARAM>
       <PARAM NAME="fieldvalue"> 1000 </PARAM>
     </FILTER>
The first filter works, and writes out the 3D Q field. However, second one
does not work as Q is not defined as a field in the solver.
Is there any possibility to address this other than extending the related
solver to contain the calculation of the field?
Thanks,
Asim
-- 
Asim