CONTENTS
BLOCK AND INPUT FILE SPLITTING
IF A LIMITER IS DESIRED, USE IFLIM=4. This will allow for consistent
results with block splitting; iflim=3 is not recommended - iflim=4 is
basically a correct implementation of iflim=3 for multiple blocks, and
should now be viewed as the recommended limiter for any case that needs one.
Also, for exact consistency between split and unsplit grids, version 5
emulation (i.e. "Install -v5) should not be used. Version 5 (and earlier
versions) made an approximation for cell volumes at 1-1 block interfaces
that has been eliminated in version 6 in favor of the exact treatment.
The input file part of the splitter works by first converting the
unsplit CFL3D input file to a TLNS3D map file, splitting the
TLNS3D map file, then converting the split TLNS3D map file back
to a CFL3D input file.
Caveats: The conversions from the CFL3D input file to a TLNS3D
map file are not perfect! The user is urged check the
resulting split CFL3D input (and patch) files. A useful
check before actually splitting the files is to run this
splitter with the number of splittings = 0, and the
output grid file as null. This will cause to code to go
through the translations, but the "split" files will
have the same numbers of blocks, and the "split" grid
will not be output. A "diff" or "gdiff" will point
to translation-induced differences that should be
easier to sort out than when coupled with true splitting.
Note that the 2-step process almost always results in a
*reordering* of some boundary condition segments.
Sample splitter input file:
This example splits block 1 in half in the i-direction, then splits each
of the two resulting blocks in half in the j-direction; i.e. block 1 is
split into 4 eqidimensioned blocks.
Where:
Following the value of nsplits, nsplits triplets of integers
must appear, one integer of the triplet per line:
The 0 index shortcut could still be used in the j
and/or k directions provided there is only one split in
block 6 in either the j and/or k directions. For sensitivity (derivative) evaluation, CFL3Dv6 uses complex variables.
For geometrical derivatives, this requires that the grid be complex-valued.
To split a complex-valued grid, use SPLITTERCMPLX rather than SPLITTER. All
the information above holds for the complex case, except that now both the
split and unsplit grids are complex-valued. FILE CONVERSION
The splitter may also be used to convert files from formatted to
formatted and vice versa, and from one cfl3d input file type to another.
For example, to convert the formatted grid file grid.fmt to the
unformatted grid file grid.unf and at the same time convert the version 4
input file cfl3d.inp_v4 to a version 5/6 input file cfl3d.inp_v6: LOAD BALANCING
Page Curator and NASA Responsible Official:
Christopher L. Rumsey Last Updated: January 16, 2007
INPUT (UNSPLIT) FILES
cfl3d.inp
ronnie.inp
grid.unf
sd_grid.unf
ICFLVER IRONVER IGRDFMT ISDFMT
5 1 1 1
OUTPUT (SPLIT) FILES
cfl3d.inp_split
ronnie.inp_split
grid_split.unf
sd_grid_split.unf
ICFLVER IRONVER IGRDFMT ISDFMT
5 1 1 1
NSPLITS
2
1
1
0
1
2
0
INPUT (UNSPLIT) FILES
cfl3d.inp_v4
null
grid.fmt
null
ICFLVER IRONVER IGRDFMT ISDFMT
4 1 0 1
OUTPUT (SPLIT) FILES
cfl3d.inp_v6
null
grid.unf
null
ICFLVER IRONVER IGRDFMT ISDFMT
5 1 1 1
NSPLITS
0