Hello Community,
I would like to import my time dependent solution data from Fluent to VisIt. I already had success by importing a .cas and .dat (uncompressed) file to VisIt, but I am not able to combine a .cas file with a .dat database.
Other formats which can be converted by Fluent, like Ensight Gold or TecPlot cannot be displayed.
Has anyone ever used this tool for CFD postprocessing. For single time step analysis, VisIt creates beautiful plots with great performance. I would like to analysis a whole timestep-data series with it. Maybe someone knows some file formatting trick or has even a short tutorial.
Kind regards,
Karl T
Why you are not using provided CFD-Post, which is quite powerful for visualizing transient data from Fluent? What is the point to go this rather cumbersome way of postprocessing?
Dear Karl,
Could you please provide a snapshot of your post processing with VisIt? I usually do post processing using Tecplot or paraview.
Regards,
Ehsan
Dear Community,
I finally managed to import a dataseries.
Ehsan Asgari: Thanks for the support, but we also use TecPlot in our lab but it can actually understand .cas.gz and .dat.gz files which makes it more comfortable when using Fluent. However, the "advanced" VisIt data import for Fluent and TeyPlot user is highly depressing ;)
--> For everyone struggling with the data implementation, here is a short instruction:
1. VisIt is not made to interpret .gz files. Also the standard data file storage of Fluent is not ideal for this Software. It requires a uncompressed .dat and .cas file for every time step. Tag the setting in calculation activities to create data files each time. The files should be saved uncompressed using this method. Otherwise, Fluent needs a register file telling it to store files uncompressed.
2. After computation, open up the FFF path and mark both 0001-000x (not 0000) .cas and .dat databases in the "VisIt open data assisstant". Make sure to select the Fluent interpreter.
3. Visit should show enable the time series bar in the main window. Mesh and field information can now be selected for every time step.
However, this workflow works now for me (after a huge amount of trial and error attempts), VisIt (2.13.2 - windows platform) cannot handle more than 200-300 timestep simulations. Note that this may vary due to the data file size. It can also be a bug or a setting I did not found yet. I also did not install the parallalization option on my machine, so VisIt may not support too big data sizes. In fact, VisIt is made for huge data files so my installation may not be ideal. Also mentionalbe: I use a dos system and VisIt is clearly optimized for UNIX based machines.
Thomas Frank Thanks for the reply: Our students use CFD-Post for university projects but our team thinks that it is a bit slow and not optimal for making beautiful plots for conferences. Other software like ParaView (for most people diffucult to work with) also offers tons of different implemented tools and kits for various operations. VisIt also is actually made for huge data files and optimized for cluster parallelization. It's quite fast (also when running on single cores) and supports over 100 file formats. Pick one of your Fluent solved files and try it out. It creates very beautiful vizualiations.
Kinds regards
Karl Tschurtschenthaler : Thank you for sharing your observations. Regarding the speed of CFD-Post I might agree in dependence on what you like to achieve. But a student of mine managed to postprocess a transient data set from a scale-resolving SAS simulation on a mesh with 120 Mill. cells and to generate from this transient simulation over more than 1024 timesteps a photorealistic movie in Full-HD (it was the aerodynamic simulation for the DrivAer car model with mirroring effects, differently colored car parts like e.g. metallic rims, etc.). So from this perspective I personally found CFD-Post not too bad.... And the created images from the flow visualization were perfectly suited for a journal publication.
Hi,
I have the same problem with CFD-Post ... so dear Professor Thomas Frank, please could you give me some tips to have a better images from CFD-Post ?? Which format to use ...etc?
Best regards.
For CFD-Post the only tip which I can give is, to turn on best possible image quality, no compression. Than the generated JPEG and MP4 should be ok. And avoid resizing /rescaling of the images, i.e. generate the images in the size of their final use. That result in 300 dpi for print purposes and 1:1 images for material used on a screen (e.g. like movies).
Regards,
Dr. Th. Frank.
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