Learning Forum

[livingquarshie]

Hello,

I run my ANSYS Fluent simulations on a supercomputer and need to write output files every 0.001 seconds to obtain the right information I need for post-processing. Currently, I generate both .cas.h5 (to enable restart) and .dat.h5 files at each step, but this results in a huge number of files and significantly slows down my simulation. For post-processing, I only need velocity and pressure data (using Tecplot 360), but Fluent writes 80+ variables by default.

My questions:

Is it possible to write only the .dat.h5 file at every timestep, and just the necessary .cas.h5 files for restart? Will this still allow me to restart the simulation from the last saved step?

Can I limit the variables written to the .dat.h5 files to only certain variables , to reduce file size and speed up simulations? If so, how can I set this up?

Any guidance on efficient file management and restart strategies would be greatly appreciated!

[Essence]

Hello,

If you need just the pressure and velocity data, you can use Solution data. File > Export > During Calculation > Solution Data.

[livingquarshie]

 

Thank you for your reply. I actually need pressure, velocity and particle diameter. I used the particle diameters data in post processing to calculate the concentrations of the particles. Is there any way around that or it mean using the particle history data will automatically come with all the variables in the data file quantities? Is it possible at all to select the variables that I want when exporting the particle history data?

 

[Essence]

Yes. Please navigate to File > Export > Particle History Data > Quantity > Particle Variables > Particle Diameter.

[livingquarshie]

 

Okay. I tried that, but what I want to do is to write an output files at a specified flow time or time step during the calculations. Say if i run the simulation for say 5 seconds, and I write file at every time step ( with dt of 0.01 sec) then I will get 500 .dat.h5 files at the end of the simulation, which I will use for my post-processing. But when I do this I get about 83 different variables in each data file. Is there a way I can write these files during calculation by specifying the number or type of varibales I want in the data file? It looks like the option you gave will only write the solution data file at the end of the simulation. In my case, I will use the data for post-processing use Tecplot 360.

 

 

[Essence]

You can use "During Calculation" option.

[livingquarshie]

Thank you. That works. But is it possible to write the case file at different time than the data file? Like I write data file every 1 time step and may be case file every 1000 time steps.