[vtkusers] FLUENT CellDataToPointData inconsistencies

Thu Jan 13 10:07:01 EST 2011

Sorry about that, it seems that I didn't check to see the maximum file size
for the university web servers. Here is another pair of links that should
work.

http://dl.dropbox.com/u/689267/oneram6_fine_sep_2.cas
http://dl.dropbox.com/u/689267/oneram6_fine_sep_2.dat

Thanks for looking at them, this is really vexing me. What is most
frustrating, is that if I load the files into ensight, then convert them to
ensight files then load them into VTK it works fine, I am wondering if
Ensight assumes something about the files that VTK doesn't that allows it to
give me the no slip condition I am after.

Thanks,

Kevin

On Wed, Jan 12, 2011 at 2:20 PM, Frederic DANESI <frederic.danesi at dinccs.com
> wrote:

> Hi Kevin,
>
>
>
> I was hoping to give it a try, but I am unable to load your files (internal
> server error).
>
> However, it seems to me that what you’re getting from vtk is correct: if
> you have only celldata as input, then you have already lost the point data
> on the boundary (wall), since pointdata ßà celldata conversion implies
> that an average value is computed … so either your .cas file does not
> enclosed point data, or the FLUENTReader does not read them … provide me
> with your files, and I will try as soon as I can.
>
>
>
> HTH,
>
> Fred.
>
>
>
> Cordialement,
>
> F.Danesi
>
> --
>
> Responsable Développement Informatique et Travail Collaboratif
>
> Centre Technique DINCCS (Centre Technique Dédié à l’Ingénierie Numérique,
> la Conception Collaborative et la Simulation)
>
> MICADO / DINCCS
>
> Pôle de Haute Technologie, BP 90005
>
> 08005 Charleville-Mézières Cedex
>
> Tel. : +33 (0) 3.24.41.69.55 / +33 (0) 6.62.76.13.32
>
> Email : frederic.danesi at dinccs.com
>
> Web : www.afmicado.com / www.dinccs.com
>
>
>
> -----
>
>
>
> *DISCLAIMER :*
>
> This email and any files transmitted with it are confidential and intended
> solely for the use of the individual or entity to whom they are addressed.
> If you have received this email in error please notify the system manager.
> This message contains confidential information and is intended only for the
> individual named. If you are not the named addressee you should not
> disseminate, distribute or copy this e-mail. Please notify the sender
> immediately by e-mail if you have received this e-mail by mistake and delete
> this e-mail from your system. If you are not the intended recipient you are
> notified that disclosing, copying, distributing or taking any action in
> reliance on the contents of this information is strictly prohibited.
>
>
>
> *De :* vtkusers-bounces at vtk.org [mailto:vtkusers-bounces at vtk.org] *De la
> part de* Kevin Hoopes
> *Envoyé :* mercredi 12 janvier 2011 20:16
> *À :* vtkusers at vtk.org
> *Objet :* [vtkusers] FLUENT CellDataToPointData inconsistencies
>
>
>
>
>
> Hello,
>
>
>
> This is my first post to this list after being a casual observer for a
> while. Let me describe my problem. I have a data set that I produced in
> FLUENT that I am trying to load into a program that I wrote in VTK. As I am
> sure everyone knows FLUENT is a Computational Fluid Dynamics analysis
> package. One of the tenets of CFD that I exploit in my program is what is
> called the no slip condition. That the velocity will be zero at the wall or
> obstacle. The problem is that when I load my FLUENT data into VTK convert it
> to point data and then write it as a vtu file and then examine it in
> ParaView there are no points that have zero velocity, the points are there,
> there is just nowhere where its zero. But at the same time, if I export the
> data from FLUENT in ensight format and then read it into VTK or ParaView, it
> works as expected. Also, if I load the FLUENT data into the EnSight program
> it also works. Tecplot also works. Both of these programs show the zero
> velocity condition at the wall. So In summary here is my problem
>
>
>
> FLUENT file -> CellDataToPointData -> Examine in VTK = No zero velocity
> locations (this is done in my main program, the attached is but a sample of
> what I am trying to do)
>
> FLUENT file -> CellDataToPointData -> write to VTU -> ParaView examination
> = No zero velocity locations (this is what the attached program does)
>
> FLUENT -> Point Data formated ensight file -> ParaView examination = zero
> velocity locations as anticipated
>
> EnSight reading fluent files -> write to ensight file -> Paraview
> examination = zero velocity locations as anticipated
>
>
>
> From what I can tell there is something going on either with the Fluent
> reader in VTK or the celldatatopointdata that is producing different results
> and, in my opinion, changing the data.
>
>
>
> As a side note, loading the FLUENT files directly into Paraview doesn't
> really seem to work. I am experiencing the same issue that is described
> here,
>
>
>
> http://www.mail-archive.com/paraview@paraview.org/msg10346.html
>
>
>
> but this is not just a ParaView problem, when I use thresholding in VTK to
> find the Zero Velocity boundries it works if I start from a FLUENT exported
> Ensight file but does not work if I start from a FLUENT file. The difference
> it seems is using FLUENT's celldatatopointdata or VTK's
>
>
>
> Now, the reader will have to understand a few things in order to hopefully
> provide some help.
>
>
>
> 1. I am doing University research and am not working for
> a commercial company
>
> 2. I am new to VTK and Paraview and CFD in general so go easy on me
>
> 3. There are quite possibly options I could be using in the FLUENT, the
> FLUENT reader or CellDataToPointData or XMLUnstructuredGridWriter that could
> solve my problem
>
> 4. I am not claiming that VTK is messing up and that I am guiltless, its
> probably some option I don't understand.
>
> 5. Maybe there is some way to have fluent not do a multiblock dataset?
>
>
>
>
>
> Here is my test C++ code
>
>
>
> #include<vtk/vtkPoints.h>
>
> #include<vtk/vtkPolyData.h>
>
> #include <vtk/vtkPolyDataWriter.h>
>
> #include <vtk/vtkUnstructuredGrid.h>
>
> #include <vtk/vtkIdList.h>
>
> #include <vtk/vtkFLUENTReader.h>
>
> #include <vtk/vtkUnstructuredGridWriter.h>
>
> #include <vtk/vtkCellDataToPointData.h>
>
> #include <vtk/vtkXMLUnstructuredGridWriter.h>
>
> #include <vtk/vtkMultiBlockDataSet.h>
>
>
>
> #include <vector>
>
>
>
> using namespace std;
>
>
>
> int main () {
>
> cout << "Begin Reading File." << endl;
>
> vtkFLUENTReader *fluent = vtkFLUENTReader::New();
>
> fluent->SetFileName("./oneram6_fine_sep_2.cas");
>
> fluent->Update();
>
>
>
> vtkCellDataToPointData *c2p = vtkCellDataToPointData::New();
>
> c2p->SetInput(fluent->GetOutput()->GetBlock(0));
>
> c2p->Update();
>
>
>
> c2p->GetOutput()->Print(cout);
>
>
>
> vtkXMLUnstructuredGridWriter *xmlwriter =
> vtkXMLUnstructuredGridWriter::New();
>
> xmlwriter->SetInput(fluent->GetOutput()->GetBlock(0));
>
> xmlwriter->SetFileName("./sep_test.vtu");
>
> xmlwriter->SetDataModeToBinary();
>
> xmlwriter->Write();
>
>
>
> }
>
>
>
> And here are some links to the FLUENT files that I am using, they are
> pretty giant, 1.5gb in total, but they are hosted at my school so hopefully
> it will be fast.
>
>
>
> http://cafestuff.groups.et.byu.net/oneram6_fine_sep_2.cas
>
> http://cafestuff.groups.et.byu.net/oneram6_fine_sep_2.dat
>
>
>
>
>
> I would also be happy to make the EnSight versions of the same files
> available if that would help.
>
>
>
> Let me know if there is anymore info that I could provide and thank you in
> advance, hopefully it is just some silly mistake of mine, it would really
> help my research to get this working.
>
>
>
> Kevin Hoopes
>
> khoopes at byu.edu
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20110113/d8a1bd05/attachment.htm>