Learning Forum

[wang wen bo]

Hello exeryone,I want to implement transient data transfer of two different computing models in fluent. I extracted the profile file of the first computing model that changes with time by using execute command and TUI Command, but I encountered problems when importing the profile file into the second computing model. When reading a profile file using TUI Command, I found that I could only read one file at a time, and after defining it as an entry boundary condition, I don't know how to write TUI Command in execute command to read the profile file of the next time step and use it as the entry boundary condition. Is there any way to solve this problem？

[Rob]

There is, but it's not as simple as you may want. You will need to read the new profile every some timesteps, and know what the filename is for each update, then tell the boundary to use that new profile file. 

It may be safer to use a journal, or have a look at the Solution steering. A normal execute commands approach might work, note, if you add %t to the name when saving files it'll add the timestep number to the name, so file_%t  at the fifth timestep will be file_0005  (exact number of 0 may vary). 

[wang wen bo]

 

Do you mean to use the way of journal to realize transient data transfer between two models? Can’t I use the method of profile file to complete this operation? I used the method of adding %t when saving the profile file of transient data of each step, so I exported the profile file of each time step. However, I found during the import that only one profile can be imported at a time, and the second profile imported overwrites the previous profile

 

[Rob]

Correct, so you need to trigger the profile change at intervals. You may be able to load them all at the beginning, but not attach them to the boundary. 

[wang wen bo]

Thank you for your answer. Could you tell me in detail how to use journal to achieve data transfer between the two models? I want to extract the outlet pressure of the first calculation model as the entry boundary condition of the second calculation model. As far as I know, journal is a function of recording GUI operations. But how do I implement the GUI to pass the data from the first computational model to the second model?

[Rob]

Ah, don't use the GUI for journals. The TUI is far safer, and in general, easier to read. Click into the text window in Fluent and press   Read what's there. Type in one of the menu titles (File, Display etc) and press , press a second time to see the new menu list. Repeat. If you use the Search function in Fluent it may help, or use the GUI to show which menus to look inside. Use "q"  (Q) to move up a menu. A hint,

/define/boundary-conditions/

would be a good place to start. The first / infront of define is important as it forces the command to run from root, otherwise if you forget to revert to root when looking in the TUI the command may work, fail or do something weird which tends not to be what you want. 

 

[wang wen bo]

Thank you for your answer. However, I am very sorry for not understanding your meaning. I used TUI when importing the profile file, as shown in the following figure, but when I used TUI to define the boundary conditions, I found that I could only define the profile file imported in the last step, and could not define the corresponding profile data for each time step. Is there any video tutorial or case file you can refer to for implementing transient data transfer between two models？Thank you again for your answer！

[Rob]

You'll need to combine with Execute Commands or Solution steering to update the profile every some time steps. If the solution changes sufficiently to need to update the boundary profile every time step you may need to reduce the time step.