Learning Forum

[rachelda9]

Hi!

Recently I downloaded the student version of Fluent 2024R2. I have simulations that worked perfectly in my previous 2022R2 student version, but now I get different results, even though I changed nothing and only opened the case in the new version.

After further inspection, I noticed that when I go to Results->Particle Tracks and try displaying User Values that I define in my DPM model, all show zeros. Also, the Residual of O2 for example, jumps suddenly to 2e1 (after running the DPM).

My simulations solve a continues flow and runs a DPM simulation each 25 iterations. I use UDFs to update the scalars, define sources and define my particle law.

The number of scalars is defined correctly, all my functions are compiled with no errors and I used massages throughout my code to make sure the UDFs are running and the values are indeed not zero (for example, if I print P_USER(p,7), I get the correct number).

What could possibly be the problem? I cannot run the simulation in the previous version due to the license expiration. Is there something new I need to define in the new version that wasn’t previously required?

 

[Prashanth]

It appears that the issue you're encountering with the User Values displaying as zeros in your DPM model and the sudden jump in residuals after running the DPM could be related to changes in the Discrete Phase Model (DPM) in the newer version of Fluent. Preliminary comment without looking at your entire code..: According to the documentation for Fluent 2024 R2, there have been some changes to the DPM, including the removal of the P_...() macros, which are no longer supported. Instead, you should use the TP_...(tp) macros for the Tracked_Particle * argument type and the PP_...(pp) macros for the Particle * argument type. Similar changes like these could potentially affect how user-defined values are handled and displayed in the results.

Given these updates, it's possible that you may need to adjust your UDFs to align with the new macro definitions and any other relevant changes in the Fluent 2024 R2 version. If you're using any features that have been updated or replaced, you'll need to modify your simulation setup accordingly.