Simple Pipe Acoustics - the very basics

[raback]

Hi

I looked quickly on the original sif file but could not see any reference to multigrid. However, it seems that you would be asking for geometric multigrid which requires a series of meshes to be available. For Helmholtz equation particularly of this size multigrid is hardly very beneficial.

-Peter

[mzenker]

Hi,

I have quickly re-run the case with the files posted by JoeD. I did it from the command line - just cd to the project directory and type ElmerSolver. Then it runs without error. If I open the project in ElmerGUI and run it, I get the error you reported.
I don't have the time right now to find out in depth why it fails with the GUI. However I did a quick diff between the sif file generated by the GUI and the one which is in the folder when you download it, and there are some differences. You might have a look at them and adjust the corresponding settings in the GUI.

HTH,
Matthias

[Adev]

Thank you both Peter and Mathias,
I ran it from the Command prompt as suggested and received the exact same error message as captured in the attached image. In case it matters, I am running the version of ELMER downloaded and installed on September 29, 2019.

[kevinarden]

If you have not already, I suggest doing some of the elmer tutorials form the tutorial document just to get a feel for elmer work flow and to see if it works on other problems.

[kevinarden]

You may be interested in this post.

viewtopic.php?f=3&t=5606

[Adev]

All,
I have followed all your advice, including the advice on the referred topic by Kevin, with no success, and running other unrelated Tutorial examples.
The sample files I ran are the exact copies of the files in the tutorials, and the instructions were followed line-by-line in the Tutorials Manual.
E.g. Tutorials 5 and 16 run properly and produce the Tutorial results, but the acoustic pipe problem CVT-P does not.

BTW, with Tutorials 5 and 16, launching Paraview as instructed in the Tutorials Manual leads to nothing … as if Paraview was not launched at all.

When the Elmer manuals and supplied tutorial examples chase a new user around the block, it is frustrating, particular when the Forum advised solutions are effectively to go "read the Manual".

If there is an expert available willing to line by line follow the tutorials as in the Manual, they will see the problems and be able to give constructive advice. I completely recognize everyone has time constraints and I am patient.

I will continue to run through Tutorials but at some point, going through technologies unfamiliar to me like a parrot, has limited value and does not solve the underlying problems with incomplete documented tutorials leaving a new user guessing and unable to make progress.

To reiterate, my primary interest and questions relate to the simple pipe acoustic problem CVT-P which requires mystery/unrevealed steps to run successfully. Anyone willing to reveal those mystery steps, please help.

[kevinarden]

I downloaded the files and it ran with no issues. Perhaps you can post what OS you are using and how did you install Elmer. Also it would be helpful to post your files for the case and they can be reviewed.

Kevin

[mzenker]

Thank you both Peter and Mathias,
I ran it from the Command prompt as suggested and received the exact same error message as captured in the attached image.

Did you use the unchanged sif file from the download or did you run from the command line after having tried to do it with the GUI? That will fail because the GUI overwrites the sif when it loads the project. So you would have to download JoeD's project folder once more and run directly from the command line.

HTH,
Matthias

[Adev]

Thank you for your time and help Mathias,
I will try your suggestion.
In the meantime, I tried a utility that came with the Elmer installation that is called "ElmerGUItester.exe" and it produced the attached output, indicating some issues with my installation (it is strange that I was able to get correct results of some tutorials, despite this).
So, I will also post this on the "Installation & compilation" board.
I'm guessing I will have to uninstall and reinstall Elmer, but I'll browse through the other forum first.
When I have a good install, I'll retry all the acoustic and Tutorial problems and provide feedback.
Thanks again!
Adriaan

[mzenker]

Hi,

I don't think you have to reinstall since it is only complaining about missing ElmerPost - this is the old postprocessor which is superseded by ParaView, so you don't need it.

Matthias