[imjretired]

Hello everyone! I am new to the SU2 Forum and using SU2 for the first time. I have ran all of the Tutorials for structural analysis (Tutorials→Structural Mechanics) in the SU2 website (https://su2code.github.io/) to familiarize myself with the SU2 software, and I had no difficulties.

This is my problem: I have ran the Laminar Cylinder Tutorial under (Tutorials→Compressible Flow→ Laminar Cylinder) and obtained results different from the results from the ones shown in the tutorial. I have searched online for some answers. I also did runs using different using different mach numbers, and Reynolds numbers but still obtained the same results as in the example. My objective for running all the examples on the SU2 website is, to verify the reliability of the SU2 software.

Isadore

PS Enclosed are pictures of the results I could not duplicate.
Laminar_Viscosity.jpg

Pressure.jpg

[bigfootedrockmidget]

If I run this testcase, I get the expected results for viscosity and pressure. Which SU2 version are you using?

[imjretired]

Hello bigfootedrockmidget,

Thank you very much for your quick response. I am SU2 Version 7.4.0 for Windows (Serial version). Your response confirms my believe that something is wrong. Maybe I should use a different version of SU2 for windows. What do you think?

My previous employer runs a series of test runs on new versions of software before trusting it for production analyses. I usually follow this practice when using software from the internet. Thank you very much again for your quick response.

Isadore

[imjretired]

Hello bigfootedrockmidget,

I have looked at all the different versions of SU2 available on the SU2 website (https://su2code.github.io/) and noticed that the UNIX version SU2 has been in use much longer than the Windows 10 version of SU2. Based on my experience with engineering software, I believe that the older version of the software (UNIX [Cygnus] version SU2) would most likely be more reliable. Thank you very much again for your quick response. You have answered my question, and this topic is closed for me.

Isadore

[pcg]

Software is not whisky, older is not better. Tutorials are not v&v cases nor regression tests. Some pictures are out of date, or they are simply illustrative.

[imjretired]

Hello pcg,

I agree with you 100%, “Software is not whisky, older is not better. Tutorials are not v&v cases nor regression tests. Some pictures are out of date, or they are simply illustrative.” SU2 has an excellent reputation, and is used by many company and universities around the world.

As stated by bigfootedrockmidget in a previous posting, “If I run this test-case, I get the expected results for viscosity and pressure.” This gave me the clue that my version of SU2 (Windows 10) was giving me wrong answers. I learned from a different post that I was getting wrong answers because my computer has AVX-capable architecture. This means that I cannot expect trustworthy results if I use SU2 for windows 10. This is why I made the comment, “I believe that the older version of the software (UNIX [Cygnus] version SU2) would most likely be more reliable.” in a previous posting. I was referring to my personal situation.

As I stated above, I agree with you 100% and that SU2 has an excellent reputation. Thank you very much for your response. Your points are valid and logical.

Isadore

[pcg]

I ran the case and I did NOT get the values of viscosity and pressure shown in those two figures, either at Mach 0.1 or 0.3 as the author mentions.
The shape of the contours is the same but the values are not. I don't know what the author did, maybe they used different non-dimensionalization settings...
We are aware of some of these issues https://github.com/su2code/SU2/issues/1604 and we took some measures to prevent tutorials from going out of date.
It just takes time because there are no volunteers to work on something like this.
Please use the most recent version of the code, the code is the same for Windows and Linux.

[imjretired]

Hello pcg,

Thank you very much for your quick response. You understand my thinking perfectly. The information at https://github.com/su2code/SU2/issues/1604 clears up everything for me. In the future, I just need to do hand calculations and use engineering judgment to verify results when using the tutorials. I will follow your recommendations and use “ the most recent version of the code, the code is the same for Windows”. I hope that I was not too much of a pain!

Isadore