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Old

snappyHexMash and 'waved' snapping

Posted August 13, 2013 at 04:54 by skeptik (CFD notes)

I had a problem


I've analyzed the problem successfully today.

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1. To prevent such behavior of sHM the mesh should not have 'empty' patches. So if you need prism layer at the symmetryPlane, you should change patch type only on final stage of your meshing process.

2....
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Old

Quite Beautiful - spiral tube

Posted August 8, 2013 at 06:59 by skeptik (CFD notes)

Another rare case could be so cool: good mesh, good residuals, good y+. So sad, cause it's not mine PhD work)

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It's really interesting, the U profile in spirals. At the peripheral regions flow accelerates, it needs to be investigated in light of heat transfer problems. Also, question about proper turbulence model is opened cause kOmegaSST sometimes gives wrong results in whirled and circular flows....
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Old

Useful LES tools in Fluent - Part 2

Posted August 2, 2013 at 04:27 by sbaffini (NuTBox)
Updated December 21, 2016 at 10:09 by sbaffini

A couple of routines i regularly use to output solution files in more manageable ascii files for post-processing in MATLAB. Of course this only makes sense when working in simple geometries where cells have regular patterns (e.g., simple boxes for computations in channels and ducts).

1) output.c: Used to dump an instantaneous field file

2) outputavg.c: Used to dump an averaged field file

More details can be found in the files
Attached Files
File Type: c output.c (1.3 KB, 139 views)
File Type: c outputavg.c (2.7 KB, 388 views)
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Old

Useful LES tools in Fluent - Part 1

Posted August 2, 2013 at 04:15 by sbaffini (NuTBox)
Updated December 21, 2016 at 10:09 by sbaffini

Here i collect some very basic tools i used when performing basic LES computations in Fluent.

1) Custom field function for the Q criterion (q_crit.txt, to be renamed in .scm). Some Fluent versions (12, 13 and maybe 14) only have a "Normalized Q criterion" scalar, while previous ones simply don't have it at all. This custom field function is what i used in those dark days.

2) Several initialization routines (init*.c and scalefield.c) fully described in the files...
Attached Files
File Type: txt q_crit.txt (2.3 KB, 870 views)
File Type: c initialize_chan.c (1.7 KB, 314 views)
File Type: c initialize_pipe.c (1.6 KB, 315 views)
File Type: c initTGV.c (1.3 KB, 257 views)
File Type: c scalefield.c (787 Bytes, 283 views)
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Old

relaxation factor

Posted July 24, 2013 at 10:38 by qing

Quote:
Originally Posted by misagh View Post
hi,we have under relaxation factor(<1) and also over relaxation factor(>1).
how to adjust the factors is so complicated and cant be explained easily.
you can visit this address:
www.bakker.org/dartmouth06/engs150/05-solv.ppt
p.p 16-17-...
i found it really useful.
best regards.
it is worth to take a time to read.
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