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A couple of questions on statistical Reynolds Stresses |
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September 21, 2020, 21:24 |
A couple of questions on statistical Reynolds Stresses
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#1 |
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Nick Thomas
Join Date: Sep 2018
Posts: 27
Rep Power: 7 |
I am doing some simulations where I am outputting the statistical Reynolds stresses, but a few of these have crashed, so I've restarted from backup files. My question is whether the averaging from the backup run will include the previously averaged values from the first run, or if it will restart the averaging at its first relative timestep. For example:
Run A goes from timesteps 0 to 10,000. Averaging is delayed until timestep 5,000. Therefore the averaging for Run A's results is from timesteps 5,000 to 10,000. Run B goes from timesteps 10,001 to 15,000. Will the results I get from Run B include averaging from timesteps 5,000 to 15,000 or 10,001 to 15,000? Or something else all together? I've searched the manuals but didn't find anything on this - there's a chance I missed it somewhere though. Any help is appreciated! |
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September 21, 2020, 21:32 |
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#2 |
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Nick Thomas
Join Date: Sep 2018
Posts: 27
Rep Power: 7 |
Note - I do see the following text in the manual:
"If you want to re-initialize a give statistic (that is, remove the history from the statistic), you must shut down and restart the simulation with a new start (stop) iteration" I am assuming that this means if I restart the simulation with no changes to the original .def file, it will keep updating the previously held transient statistics values? aka the averaging of Run B would in fact include averaging from 5,000 to 15,000? |
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September 21, 2020, 23:06 |
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#3 |
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Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
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In cases this this I suggest you just do a simple experiment and work it out. Just do a simple simulation (maybe a tutorial) and test how the transient statistics works on these quick simple run when you stop and restart it.
I realise it might seem quicker to just ask the question, but working it out for yourself is usually quicker by the time you wait for an answer, and you aren't mislead by gumbies who answer your question but actually have no idea and are just guessing. This final reason is the reason I have not answered your actual question - I don't know myself
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Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum. |
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September 22, 2020, 09:41 |
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#4 |
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Nick Thomas
Join Date: Sep 2018
Posts: 27
Rep Power: 7 |
That's a good point. Thanks!
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