Save Solution Data in a Fluent Transient Simulation

asf_card · September 15, 2015, 05:52

Hello,

I am simulating a 3D unsteady flow system in fluent. This is a periodic simulation (N periods) and would be run for N*100 timesteps. I would like to save transient data (ONLY: pressure, velocity, density, and wall shear; as I have space limit) for ONLY the last 100 time steps (i.e., from timestep (N-1)*100 to N*100).

Moreover, I will pass the case onto a cluster for parallel running; so gui based commands might not be suitable in this case.

Would be grateful if you please help me.

Thanks a lot in advance.

Bruno Machado · September 15, 2015, 06:13

I think you can do it using the "Calculation Activities" in the Fluent menu. Check if the Autosave every (iteration) menu helps, otherwise you can have a look at the Execute Commands to associate it to time steps.

asf_card · September 15, 2015, 06:34

Hello,

Thanks for your advice. However, my problem is that I do not want to save at every timestep; instead, I need to save solution data only for the last 100 timesteps.

Thanks.

Quote:

Originally Posted by Bruno Machado

I think you can do it using the "Calculation Activities" in the Fluent menu. Check if the Autosave every (iteration) menu helps, otherwise you can have a look at the Execute Commands to associate it to time steps.

LuckyTran · September 15, 2015, 22:41

Basically Bruno is right. Iterate the first ## time-steps without using calculation activities. Then once you hit the time-step that you want to start saving, turn on all the calculation activities. You can set up the calculation activities through GUI or TUI. If you have access to the GUI and aren't familiar with the TUI, it's probably easiest to do it with the GUI. Just bring your .cas and .dat off the cluster and open it locally when you're ready to do the swithc. Otherwise, doing it with the TUI is pretty easy to do once you learn how to enter commands through the TUI window.

However, you cannot save only the pressure, velocity, density, and wall-shear in a Fluent .dat as all the dynamical variables are always saved. You can save a limited number of variables, but it would have to be an .ascii text file or something similar and not of the Fluent .dat type, which means you wouldn't be able to load the saved files again in Fluent.

September 15, 2015, 05:52	Save Solution Data in a Fluent Transient Simulation	#1
asf_card New Member anonym Join Date: Sep 2015 Posts: 2 Rep Power: 0	Hello, I am simulating a 3D unsteady flow system in fluent. This is a periodic simulation (N periods) and would be run for N100 timesteps. I would like to save transient data (ONLY: pressure, velocity, density, and wall shear; as I have space limit) for ONLY the last 100 time steps (i.e., from timestep (N-1)100 to N*100). Moreover, I will pass the case onto a cluster for parallel running; so gui based commands might not be suitable in this case. Would be grateful if you please help me. Thanks a lot in advance.

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September 15, 2015, 06:13		#2
Bruno Machado Senior Member Bruno Machado Join Date: May 2014 Posts: 271 Rep Power: 13	I think you can do it using the "Calculation Activities" in the Fluent menu. Check if the Autosave every (iteration) menu helps, otherwise you can have a look at the Execute Commands to associate it to time steps.

September 15, 2015, 22:41		#4
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,761 Rep Power: 66	Basically Bruno is right. Iterate the first ## time-steps without using calculation activities. Then once you hit the time-step that you want to start saving, turn on all the calculation activities. You can set up the calculation activities through GUI or TUI. If you have access to the GUI and aren't familiar with the TUI, it's probably easiest to do it with the GUI. Just bring your .cas and .dat off the cluster and open it locally when you're ready to do the swithc. Otherwise, doing it with the TUI is pretty easy to do once you learn how to enter commands through the TUI window. However, you cannot save only the pressure, velocity, density, and wall-shear in a Fluent .dat as all the dynamical variables are always saved. You can save a limited number of variables, but it would have to be an .ascii text file or something similar and not of the Fluent .dat type, which means you wouldn't be able to load the saved files again in Fluent.