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Useful LES tools in Fluent - Part 2

Posted August 2, 2013 at 04:27 by sbaffini (NuTBox)

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, 120 views)
File Type: c outputavg.c (2.7 KB, 234 views)
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Old

Useful LES tools in Fluent - Part 1

Posted August 2, 2013 at 04:15 by sbaffini (NuTBox)

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, 394 views)
File Type: c initialize_chan.c (1.7 KB, 175 views)
File Type: c initialize_pipe.c (1.6 KB, 145 views)
File Type: c initTGV.c (1.3 KB, 162 views)
File Type: c scalefield.c (787 Bytes, 162 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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Old

As good as ICEM

Posted July 19, 2013 at 06:13 by skeptik (CFD notes)

Tetra mesh with prism layers generated in SALOME.

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Old

Q-criterion isosurfaces in MATLAB

Posted July 1, 2013 at 11:33 by sbaffini (NuTBox)

Let us suppose you have the following matrices:

x(nx,ny,nz): x coordinates of your grid

y(nx,ny,nz): y coordinates of your grid

z(nx,ny,nz): z coordinates of your grid

dudx(nx,ny,nz): x-wise derivative of x-wise velocity component

dudy(nx,ny,nz): y-wise derivative of x-wise velocity component
.
.
.
dwdz(nx,ny,nz): z-wise derivative of z-wise velocity component

This is, more or less, how i...
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