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Double precision case open in single precision solver.

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Old   March 26, 2013, 06:04
Default Double precision case open in single precision solver.
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Hi,

Has anyone encountered the said issue? I run some calculation in double precision, get some results and then close FLUENT and WB. Sometime later, I want to continue calculation from the same case and data. WB asked me to "edit" from the "resultd' cell as if I "edit" from "setup" cell the calculated data will be erased. The preference in WB is set such that FLUENT is double precision by default. But whenever I open FLUENT from "results" cell, it is always single precision.

How to handle this? Thanks!
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Old   March 26, 2013, 08:27
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I think you can't open FLUENT from "Results" tab. You need to open it using "Solution" tab. The Workbench preferences will be different for different instances of Fluent simulation. You need to make sure the preferences for every FLUENT simulation is double precision.

OJ
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Old   March 26, 2013, 12:03
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Thanks OJ.
Sorry, my mistake, I meant to say "solution" tab. "Results" tab is CFD Post. The preference for FLUENT is already be set to double precision, besides at the first time starting FLUENT from WB I have a chance to make sure that. The properties of 'solution' is single precision, fixed. This tab is 'generated' while I am running calculation in FLUENT, don't think I can do anything with it.

Any way to handle this? Or must I calculate everything (from the beginning to the end) in a single FLUENT session? Or must I copy the latest case and data file and then import them into a double precision FLUENT elsewhere?

I am quite concern about this as if I continue on a single precision solver, the precision might get affected.

Thanks!
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Old   March 26, 2013, 12:21
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How are you sure the WB preferences are always fixed? When you right click on Solution tab in WB, select Properties and look towards right hand pane, what do you see as the default preferences? Is it double or single?

OJ
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Old   March 26, 2013, 12:57
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Hi OJ,

1, In WB, tools-> option->FLUENT tab, I make sure by default it is in double precision.
2, When opening FLUENT for the first time, say, after I get the mesh done, I can make sure that it is double precision in the launcher.
3, Properties for setup is double, but it seems can be changed (there is a downward selection arrow on the right). But the properties for solution is single, fixed.

So basically I just don't know why when I want to continue calculate a double precision case, the solver itself become single precision...?
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Old   March 26, 2013, 14:35
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Right click on Solution >> Properties
At right hand pane, uncheck "Use Setup Launcher Settings"
Now the Precision option will be editable
Set Double Precision.

Does this work?

OJ
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Old   March 27, 2013, 04:19
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Yeah! It works! Thank you very much, OJ!
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