Fluids

Fluids

Residuals-output from Fluent in batch mode (TUI)

    • ujjsf
      Subscriber

      Hey there!

      I'm a engineering student doing my master thesis using Fluent for some flow simulations via batch mode on a Linux cluster.

      Im searching for a way to export the residual history of a simulation automatically to a textfile using TUI commands in a Journal file. There is a TUI option to plot the residuals to file (/plot/residuals-set/plot-to-file *filename*) which only creates an empty textfile, doesn't matter if I use the command before starting or after finishing the calculation. In some internet forums people say, I need to use the command after the calculation and then calculate one more iteration, which does work for GUI mode but not for batch mode - the created textfile remains empty in this case.

      Is there any way to export the residuals from Fluent? Maybe even during the calculation (which would be amazing!)? I know there are some ways programming a scheme script or bash script but I guess this kind of basic function should be implemented in Fluent?

      Maybe even a way to plot for example time step size, iterations per time step and other simulation data over time during the calculation?


      Kind regards and thanks a lot in advance for your help!

      ujjsf

    • s_88j4ba
      Subscriber
      Hi ujjsf I've experienced the very same problem, getting an empty file.txt when using the required plot-command in the journal file!!! For the GUI, though, it works fine...
      i) initializing the solution ii) typing /plot/residuals-set/plot-to-file "file.txt" in the console iii) and running the calculation.
      But in batch mode, there's no chance, neither on the cluster nor on the local machine. Same Fluent version!
      Did you maybe figured out how to solve it, or anybody else that can help or explain why ANSYS FLUENT needs to make it so hard to get the residuals
      kind regards
      panda_ray
    • Swathi V. V.
      Ansys Employee

      You can write an output file, which will contain the output that Ansys Fluentwould normally print to the screen (for example, the menu prompts and residual reports).
      Please refer to : https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v221/en/flu_ug/flu_ug_sec_batch_execution_unix.html
    • s_88j4ba
      Subscriber
      hi ujjsf I don't know if you're still struggling with exporting the residuals?! Maybe you'll have a look here https://doku.lrz.de/pages/viewpage.action?pageId=43321282!
      With the help of paragraph "Creation of Graphics Output from ANSYS Fluent in Batch Mode" I was able to solve my problem!

      kind regards
      panda_ray
    • ujjsf
      Subscriber
      Hey panda_ray,
      thanks a lot for your reply! This is a nice solution for calculations surveillance! I'm actually more searching for a text file with the residual data though, so I can set my own visualization preferences.
      Did anyone get the /plot/residuals-set/plot-to-file command to work in batch mode?


    • Rob
      Ansys Employee
      The transcript file includes the residual data but will need some clean up as it also contains everything else that gets pushed to the TUI. Depending on the launch options the TUI command may work, I've also got an enhancement request in for the residuals to be added to the list of monitors so we can plot that way.
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