Learning Forum

[soloviev]

Hello,nnWe are looking to load velocity/temperature profiles into a model as boundary conditions at the inlet. Can this be done in a variable manner without manually stopping the model and re-importing profiles and re-starting the model? We are hoping for a way for Fluent to re-read a new profile every either 1 or 10 or time steps.Thanks,nAlexn

[Surya Deb]

Hello, nIs the model transient and you are trying to load a transient profile?nIt is not very clear when you say re-starting the model.nWhy do you need to restart the model? Is it because you want to use the solution from one case to the other with different profile files?nCan you please elaborate?nRegards,nSuryan

[soloviev]

Yes. I have looked into this further and found that you can add transient profile files. I am doing this now by loading a csv with a column for 'time'. Does this work in the sense that Fluent will read the time and update the boundary condition variables at the given time using this transient profile file?.Thanks,nAlexn

[soloviev]

This is an example of the csv. I have the time column with the repeating time until the next time I want the profile to update (540s). Is this in the correct format? It seems to not read it properly based on my results thus far. nThanks,nAlexnn

[Karthik Remella]

,nHere is an example of the profile file format. Please refer to the following link.nThank you.nKarthikn

[soloviev]

Thank you. I see the following example: nnnHow can I do the top and bottom combined? In my file I am trying to update the transient x,y,z velocity profiles are varying time steps and at x,y,z coordinates, like the top, but at an interval of 1s, 540s, and 1140s. I posted my file above. Should I name the name transient-inlet or transient-velocity instead? But can I combine the xyzzy points and velocities with the time column?.Thanks,nAlexn

[Amine Ben Hadj Ali]

in Fluent you can consider transient AND spatial profiles at the same time: either you provide a transient input (like velocity magnitude varying over time) or spatial( velocity input varying over X,Y,Z). To have 4 dimensions you require UDF (not even easy to do..).nnI think there will be a way to do that in the feature.n

[soloviev]

Thank you. So the best way for now to do this is run the simulation, then start a case with the results from the first run, and add the new profile then continue running?

[Amine Ben Hadj Ali]

You can rely on Automatic Case Modifications Feature in Fluent: You read at the beginning all profiles, you prepare the journals to apply the right profile and then execture the modification at the moment you require.n

[soloviev]

Thank you! Is this in the user's guide? n

[Rob]

Sort of, the case modifications part is, but the commands you need (TUI) won't be other than at a very basic level in the TUI manual. n

[soloviev]

So I have looked into this a bit more (online tutorials and user's guide). Will I just use the journal to get my TUI commands to use in the automatic case modification? Or do I need to use the automatic case modification to execute reading journal files?.Thanks,nAlexn

[soloviev]

I worked on this today and found that when I write a journal that reads the profile and sets it in the boundary conditions tab, I can read it into the case fine. When I set it as a case modification, it gives me the attached error. I've also provided the commands I have set to execute in case that's helpful. It does seem to be reading the file at the specified step from the case modification, but I'm not sure why there's an error with the journal when reading that way, but not when I use the GUI to read it.Thanks,nAlexnn

[Rob]

If the profile is already loaded you should just need to set the boundary condition. Also /file/read will probably try and read a case as Fluent usually picks the first option in the list if it's not fully defined. n

[soloviev]

So I should load all profiles at the beginning? I am setting x-velocity, y-velocity, and z-velocity as Cartesian components with each modification. Will it be able to do this in one command? My journal file listed it as ~10 lines of commands.Thanks,nAlexn

[soloviev]

I also just found that it seems the proper TUI command would be file/read-journal. Thanks for pointing out that issue. n

[soloviev]

Actually, as an update, changing the auto modification command to read-journal got rid of the error! Thanks!n