Option flags are specified as follows
aflr3 -option_flag_1 -option_flag_2 ...
Option flags can be used to set basic program options.
More detailed control of the program operation is allowed using additional
parameter options as described later in this documentation.
Input and Output File Names
===========================
Input and output file names can be specified using option flags or
aflr3 [options] [name]
In this mode the [name] argument is either the case name, the full input file
name, or the full parameter file name. If only a case name is specified then an
input file with a matching case name will be searched for. File format and
compression are searched in the order that they appear in the tables that
follow. If a full input file name is specified then a compressed version of that
file is searched for (unless compression is specified in the file name). Unless
otherwise specified, the output file(s) will have the same case name as the
input file. File names follow the UG_IO file name conventions. If the final
argument is a parameter file then the options specified by [options] will be
applied after the options specified in the parameter file are applied. A
parameter file has a suffix of ".aflr3.par". For example,
"test01.aflr3.par" is a valid parameter file name with a case name
of "test01". If the parameter file is not specified as the last argument then a
new parameter file named "case_name.aflr3.par" will be written,
where case_name is the case name from the input file or from the output file
(if it is different).
UG_IO File Names
----------------
UG_IO file names are specified as
case_name.mode.type.format.compression
where case_name is the file case name, .mode is the file mode, .type is the
type suffix, .format is the format suffix, and .compression is the compression
suffix.
Suffix File Type Description
----------------- --------------------
.node NODE 3D Node Data File
A NODE file contains a list of node
coordinates.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
.snode SNODE 3D Source Node Data File
An SNODE file contains a list of node
coordinates and spacing function.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
.vnode VNODE 3D Directional Source Data File
A VNODE file contains a list of node
coordinates, spacing function, two unit
direction vectors, and two corresponding
aspect-ratios.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
.tags TAGS Surface Tags Data Grid File
A TAGS file contains a list of surface
IDs and surface BC properties.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
This file type may only be used for
input files.
.poly POLY Unstructured B-Surf Grid File
A POLY file contains a tria/quad face
boundary surface grid. This file type is
used by TetGen.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
This file type may only be used for
output files.
.stl A 3D stereo-lithography B-Surf Grid File
A STL file contains a tria face
boundary surface grid.
.surf SURF 3D Unstructured B-Surf Grid File
A SURF file contains a tria/quad face
boundary surface grid.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
.tri Cart3D TRI Unstructured B-Surf Grid File
A Cart3D TRI file contains a tria face
boundary surface grid. This file type is
generated by the Cart3D system.
.cfd++ CFD++ Grid File Set
A CFD++ grid file set contains a tria/
quad face boundary surface grid and a
polyhedral element volume grid. This
file type uses multiple files for
coordinates (nodesin.bin), elements
(cellsin.bin), and surface faces
(exbcsin.bin).
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
This file type may only be used for
output files.
.cgns CGNS Data File
A CGNS data file contains a tria/quad
face boundary surface grid and
(optionally) a polyhedral element volume
grid.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
.cobalt.grd Cobalt Grid File
A Cobalt grid file contains a tria/quad
face boundary surface grid and a
polyhedral element volume grid.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
This file type may only be used for
output files.
.egrid Ensight Gold Grid File
An Ensight Gold grid file contains a
tria/quad face boundary surface grid and
a polyhedral element volume grid. This
file type writes an additional case file
(case_name.case).
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
This file type may only be used for
output files.
.fgrid FGRID 3D Unstructured Grid File
A FGRID file contains a triangulated
boundary surface grid and (optionally)
a tetrahedral volume grid. The FGRID
file type is derived from the FAST
(PLOT3D) unstructured grid file type.
FGRID and FAST files are the same except
for optional FGRID boundary
reconnection, boundary condition, and
initial normal spacing data records.
.fluent.cas Fluent Grid File
A Fluent grid file contains a tria/quad
face boundary surface grid and a
polyhedral element volume grid.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
This file type may only be used for
output files.
.fvuns Fieldview Grid File
A Fieldview grid file contains
boundary surface grid and (optionally)
a polyhedral element volume grid.
This file type may only be used for
output files.
.gambit GAMBIT (Fluent) Neutral File
A GAMBIT Neutral file contains a tria/
quad face boundary surface grid and
(optionally) a polyhedral element volume
grid.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
This file type may only be used for
output files.
.mesh MESH 3D Unstructured Grid File
A MESH file contains a tria/quad face
boundary surface grid and (optionally)
a polyhedral element volume grid. Note
that pentahedral elements are supported
using the keywords Pentahedra5 and
Pentahedra6. The official MESH file does
not support pentahedral elements. This
file type is used by MEDIT.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
.bdf NASTRAN 3D Unstructured Grid File
A NASTRAN file contains a tria/quad face
boundary surface grid and (optionally)
a polyhedral element volume grid.
The suffix .nas and .bdf are equivalent.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
.nas NASTRAN 3D Unstructured Grid File
A NASTRAN file contains a tria/quad face
boundary surface grid and (optionally)
a polyhedral element volume grid.
The suffix .nas and .bdf are equivalent.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
.mcell NSU3D Grid File
A NSU3D grid file contains a tria/quad
boundary surface grid and (optionally)
a polyhedral element volume grid.
.foam OpenFOAM polyMesh Grid Files
A cellShape file contains a volume grid
that is comprised of points and
polyhedral elements defined by faces.
This file type may only be used for
output files.
.ufast UFAST 3D Unstructured Grid File
A UFAST file contains a triangulated
boundary surface grid and (optionally)
a tetrahedral volume grid. The UFAST
file type is identical to the FAST
(PLOT3D) unstructured grid file type.
.face TETGEN 3D Unstructured Grid File Set
A TETGEN file set contains a tria face
boundary surface grid and (optionally)
a tetrahedral volume grid. This file
type uses multiple files for coordinates
(.node), elements (.ele), and faces
(.face). This file type is used by
TetGen.
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
This file type may only be used for
input files.
.ugrid UGRID 3D Unstructured Grid File
A UGRID file contains a tria/quad face
boundary surface grid and (optionally)
a polyhedral element volume grid.
This file type can use socket or TMP
file mode if a C binary double file
format is also used.
.cogsg VGRID 3D Unstructured Grid File
A VGRID file contains a triangulated
boundary surface grid and (optionally)
a tetrahedral volume grid. This file
type uses multiple files for coordinates
and volume grid connectivity (.cogsg),
boundary face connectivity (.bc), and
boundary conditions (.mapbc).
This file type uses a fixed file format
that is either a standard ASCII file
format or a binary format specific to
the file type.
Suffix File Format Description
------ -----------------------
Formatted ASCII File or Binary Format
Specific to File Type
.r8 FORTRAN Unformatted Real*8 File Format
with Big Endian Ordering
.r4 FORTRAN Unformatted Real*4 File Format
with Big Endian Ordering
.b8 C Binary Double File Format
with Big Endian Ordering
.b4 C Binary Float File Format
with Big Endian Ordering
.lr8 FORTRAN Unformatted Real*8 File Format
with Little Endian Ordering
.lr4 FORTRAN Unformatted Real*4 File Format
with Little Endian Ordering
.lb8 C Binary Double File Format
with Little Endian Ordering
.lb4 C Binary Float File Format
with Little Endian Ordering
Suffix File Mode Description
------ ---------------------
Standard File Mode
.socket Binary Socket File Mode
Binary socket files are not directly
accessible and exist only temporarily in
computer memory.
.tmp Binary TMP File Mode
Binary TMP files are not directly
accessible and exist only temporarily in
computer disk scratch space.
Suffix File Compression Description
------ ----------------------------
No File Compression
.bz2 BZIP2 File Compression
.gz GZIP File Compression
.Z COMPRESS File Compression
The following option flags can be used to specify the input and output file
names.
-igrid case_name/input_grid_file
Specify either the case name or full input grid file name.
-ogrid output_grid_file
Specify either the full output grid file name or the output grid file suffix.
If an output grid file suffix is specified then the case name derived from the
input file name will be used for the output file names. The default output grid
file suffix is NOT_SET.
-minout
Generate minimum output messages. The default is to generate basic messages.
-out
Send all informational output to both standard output (or standard error) and
a file named case_name.aflr3.out. The default is to send all output
to only standard output or standard error.
-outf
Send all informational output only to a file named case_name.aflr3.out
only. Error messages will go to both the file and standard error. The default
is to send all output to only standard output or standard error.
Examples for specifying input and output file names are shown below.
aflr3 [options] test
Use "test" as the case name. A valid input file with a case name of "test" is
searched for and the output files will all have a case name of "test".
aflr3 [options] -ogrid .b4.ugrid test
Use "test" as the case name. A valid input file with a case name of "test" is
searched for and the output grid file will be named "test.b4.ugrid".
aflr3 [options] -ogrid test_output.b4.ugrid test
Use "test" as the input file case name. A valid input file with a case name of
"test" is searched for and the output grid file will be named
"test_output.b4.ugrid".
aflr3 [options] -ogrid test.b4.ugrid
Use "test" as the case name. A valid input file with a case name of "test" is
searched for and the output grid file will be named "test.b4.ugrid".
aflr3 [options] -igrid test -ogrid test_output.b4.ugrid
Use "test" as the case name. A valid input grid file with a case name of "test"
is searched for and the output grid file will be named "test_output.b4.ugrid".
aflr3 [options] -igrid test.ugrid -ogrid test_output.b4.ugrid
The input grid file is named "test.ugrid" and the output grid file will be
named "test_output.b4.ugrid". If "test.ugrid" does not exist and a compressed
version, "test.ugrid.gz" or "test.ugrid.Z", does exist then the compressed
version will be used.
Executable Options
==================
-host host_name
Run on remote host named "host_name". The default is to run on the local host.
-w
Send output to a new X-window using the xterm command. The default is to send
output to the current X-window or display.
-v version_name
Force use of scripts, executable and libraries in the system directories for
"version_name". The system will search for a valid directory to use as the
SimCenter system directory in the following order.
/usr/local/version_name
/simcenter/system/version_name
/Users/marcum/version_name
/Users/marcum/version_name
version_name
-dev
Use executable in current directory named as in SimCenter system directories.
-exe exe_name
Use executable in current directory named "exe_name".
-diag
List executable location and library dependencies.
-test
Run script and only echo the executable command (do not run the executable)
-dbx
Run executable using dbx debugger.
-gdb
Run executable using gdb debugger.
-ddd
Run executable using ddd debugger.
-insight
Run executable using insight debugger.
-debug
Use debug version of executable, aflr3_g.exe (if available).
-purify
Use purify version of executable, aflr3.exe.pure or aflr3_g.exe.pure
(if available).
-prof
Use gprof version of executable, aflr3_p.exe (if available).
-64
Use 64-bit version of the executable. Only required for very large grids (more
than 40 million elements). The default is to use the 32-bit version.
Parallel, Multi-Pass, and Multi-Partition Options
=================================================
Parallel, multi-pass, and multi-partition options can be specified with the
-mp np or -mpe ne and -np n option flags. In multi-pass mode grid generation is
performed one stage at a time and intermediate data is stored in temporary
files instead of memory. In multi-partition mode the isotropic grid is
generated with iterative partitioning for further memory reduction. In parallel
mode the grid within each partition is generated on different processors for
reduced execution time.
With multi-pass grid generation with a BL/SL/SNS region there are four primary
passes.
pass 1 : background grid generation and BL/SL/SNS grid generation
pass 2 : initial boundary surface isotropic grid generation
pass 3 : final isotropic grid generation
pass 4 : merge BL/SL/SNS and isotropic grid generation
With multi-pass grid generation without a BL/SL/SNS region there are two
primary passes.
pass 1 : not used
pass 2 : initial boundary surface isotropic grid generation
pass 3 : final isotropic grid generation
pass 4 : not used
In single-partition mode (np=1) pass 3 generates the entire isotropic grid
region as one partition. In multi-partition (or parallel) mode pass 3 generates
the isotropic grid region in multiple partitions that are obtained from
iterative partitioning.
In multi-pass mode the output grid file is always written as a UGRID type
(.ugrid) file with either formatted ASCII or C binary double format (.b8). If
another format or type is selected then memory for the complete grid must be
allocated for a final conversion step will be executed. For large cases this
step may exceed available memory. Instead it is recommended that if another
file type or format is desired that this conversion be performed as a separate
independent step. It can be performed on a machine with sufficient memory using
the flags "-convert case_name.b8.ugrid case_name.new_format.new_type". In
addition the calculation of grid quality data is not performed unless final
output grid file conversion is specified. For large cases this step may also
exceed available memory. It can be performed on a machine with sufficient
memory using the flag "-qstat case_name.b8.ugrid" along with any desired grid
quality data option flags.
-mp 1
Use multi-pass, single-partition mode grid generation. This flag is equivalent
to using the following parameter options.
mpartm=1
npart=1
-mp np
Use multi-pass, multi-partition mode grid generation with "np" partitions.
This flag is equivalent to using the following parameter options.
mpartm=1
npart=np
-mpe ne
Use multi-pass, multi-partition mode grid generation with partitions limited to
"ne" elements each. This flag is equivalent to using the following parameter
options.
mpartm=1
npelmax=ne
-np n
Use parallel mode with "np" processes. If multi-pass, multi-partition mode is
not specified using either "-mp np" or "-mpe ne" flags then the number of
partitions is set equal to the "np" and this flag is equivalent to using the
following option flags.
-mp n -np n
Efficiency Options
==================
-fast
Use basic Delaunay local-reconnection during field point creation and only a
single pass of quality improvement. Required CPU time will be decreased and
grid quality will be slightly degraded using this option. This flag is
equivalent to using the following parameter options.
mrec4=0
mrecm=1
nqual=1
mqrgen=0
Local-Reconnection Criteria
===========================
The local-reconnection criterion is used to optimize the element connectivity
throughout grid generation. The default criterion is a combined Delaunay and
MIN-MAX-Angle (minimize the maximum element dihedral angle). Also available is
a combined Delaunay and MAX-MIN-Rratio criterion (maximize the minimum ratio of
the inscribed radius over the circumscribed radius). The MAX-MIN-Rratio
criterion produces slightly improved grid quality at the expense of an increase
in required CPU time.
-mmr_rec
Use a MAX-MIN-Rratio criterion for local-reconnection. The default is to use a
MIN-MAX-Angle criterion. This flag is equivalent to using the following
parameter options.
mrecm=3
mrecqm=3
-mma_rec
Use a MIN-MAX-Angle criterion for local-reconnection. The default is to use a
MIN-MAX-Angle criterion. This flag is equivalent to using the following
parameter options.
mrecm=2
mrecqm=2
Isotropic Element Size
======================
The element size in the field is determined using either interpolation or
growth normal to the boundary surfaces. Element size can also be modified using
source nodes. Growth and sources are described in the following sections. The
distance between points in the grid is controlled by a distribution function
that is equivalent to the desired element size. In all cases that start from a
boundary surface grid the initial element size is determined from the spacing
between points on the boundary surface. The scaling of the initial element size
and maximum element size can be controlled with the following parameters.
-cdf size_multiplier
The initial element size is set to the local spacing between boundary surface
points multiplied by the size multiplier. The default value for ideal
tetrahedral elements is 1.2. This flag is equivalent to using the following
parameter options.
cdf=size_multiplier
cdf2=size_multiplier
-dfmax max_value
Specify the maximum allowable distribution function and use it to limit the
maximum element size. If the value is negative then the element size is not
limited by the maximum allowable distribution function. This is the default.
If the value is zero then maximum element size is limited to be less than the
maximum point spacing for the boundary surface grid. This mode can be useful to
prevent excessive growth from far-field type boundary surfaces when using
growth. And, if the value is greater than zero then the maximum element size is
limited to be less than the value specified. The maximum element size limit is
can be exceeded during local-reconnection (due to reconnection of elements) and
by smoothing during final quality improvement. This flag is equivalent to using
the following parameter options.
dfmax=max_value
Isotropic Element Size Growth
=============================
The element size in the field is by default determined using interpolation to
smoothly propagate the point spacing within the field from the boundary
surfaces. With optional growth, the element size is determined using geometric
growth normal to the boundary surfaces. Additional parameter options are
available to control element size in the field. The following flags set
appropriate parameter options for various levels of growth. Each of these flags
will usually reduce the total number of elements and increase the size of the
interior elements.
-grow growth_ratio
Use specified growth in element size in a direction normal to the boundaries.
This flag is equivalent to using the following parameter options.
mdf=2
cdfs=1.0
cdfr=growth_ratio
-grow1
Use moderate growth in element size in a direction normal to the boundaries.
This flag is equivalent to using the following parameter options.
mdf=2
cdfr=1.2
cdfs=1.0
-grow2
Use high growth in element size in a direction normal to the boundaries.
This flag is equivalent to using the following parameter options.
mdf=2
cdfr=1.5
cdfs=0.5
-grow3
Use very-high growth in element size in a direction normal to the boundaries.
This flag is equivalent to using the following parameter options.
mdf=2
cdfr=2.0
cdfs=0.0
Transparent/Embedded Boundary Faces
===================================
-transp
Do not convert transparent boundary faces with a grid BC of 3 to source nodes.
The default is to convert transparent boundary faces with a grid BC of 3 to
source nodes. This flag is equivalent to using the following parameter options.
mtransp=1
-rm_transp
Remove boundary face connectivity for transparent boundary faces with a grid
BC of 5 from the final grid. This is the same as changing their grid BC from
5 to 6. The default is to retain boundary face connectivity for transparent
boundary faces with a grid BC of 5 in the final grid. This flag is equivalent
to using the following parameter options.
mtransp=4
Adaptive Control of Element Size
================================
The element size in the field is by default determined using interpolation to
smoothly propagate the point spacing within the field from the boundary
surfaces. With optional adaptation sources the element size is locally
determined from the source. Sources can also be used to optionally define
anisotropic spacing. If either a NODE, SNODE, or VNODE file exists with the same
case name as the input surface grid file then the sources defined within that
file will be used. Sources can also be created from source type embedded
boundary surface faces. A VNODE file contains a list of source node coordinates,
desired node spacing, transformation vectors, and transformation aspect-ratios.
An SNODE file contains a list of source node coordinates and desired node
spacing. A NODE file contains a list of source node coordinates grouped in lines
and the node spacing is determined from the spacing between the source nodes.
See the output using "-help_ug_io" for a complete description of the NODE,
SNODE and VNODE file types.
-no_source
Do not use sources even if there are source node files. This flag has no effect
if there are no source node files. This flag is equivalent to using the
following parameter option.
msource=0
-trsrc
Use anisotropic sources. This flag has no effect if there are no source nodes
or if anisotropic transformation vectors are not specified (either from
transparent source surfaces or source node files). This flag is equivalent to
using the following parameter option.
mtr=1
-trsrc_grow
Use anisotropic sources with growth. The default for anisotropic sources is
to not use growth from the sources for the aspect-ratio. This flag has no
effect if there are no source nodes or if anisotropic transformation vectors
are not specified (either from transparent source surfaces or source node
files). This flag is equivalent to using the following parameter option.
mtr=2
-trds normal_spacing
Specify anisotropic transformation source surface normal spacing to be the
value of normal_spacing. By default the value set (if any) for source type
embedded surfaces is used. This flag is only applicable if there are source
type embedded boundary surface faces and if the anisotropic transformation
option is selected (-trsrc, -trsrc_grow, mtr=1, or mtr=2). This flag is
equivalent to using the following parameter option.
trds=normal_spacing
CFD Boundary-Layer (BL) Grid
============================
-bl
Generate a BL grid suitable for CFD from all boundary faces with a grid
boundary condition flag less than zero. The grid boundary condition flag can be
set in the input grid file. If it is not set in the input grid file, then all
boundary faces are set to a negative grid boundary condition value unless set
otherwise using the -bls or equivalent flag. This flag is equivalent to using
the following parameter options.
mbl=1
mrecm=3
mrecqm=3
Note that the -bl flag also automatically selects the equivalent of -mmr_rec
to specify use of a MAX-MIN-Rratio criterion for local-reconnection. To turn
off the MAX-MIN-Rratio criterion use the "-bl -mma_rec" flags. The -mma_rec
flag must appear after the -bl flag.
-blc
Combine tetrahedral elements within BL regions to form pentahedra (prismatic
and pyramid). With this option an output grid file type that supports
pentahedra should be specified. This flag is only applicable in cases with a BL
grid (-bl or -bls flag). This flag is equivalent to using the following
parameter option.
mblelc=1
-blc2
Combine tetrahedral elements within BL regions to form pentahedra (prismatic
and pyramid) and hexahedra. With this option an output grid file type that
supports pentahedra and hexahedra should be specified. This flag is only
applicable in cases with a BL grid (-bl or -bls flag). This flag is equivalent
to using the following parameter option.
mblelc=2
-blpr
Protect the BL region by reducing the spacing in the adjacent isotropic region.
This option can be useful if the physical BL region is very thick and the grid
BL region is not as thick. This flag is only applicable in cases with a BL grid
(-bl or -bls flag). This flag is equivalent to using the following parameter
option.
cdf2=0.7
-bls id_1,id_2,...,id_n
Generate a BL grid from specified surfaces. Set the grid boundary condition to
a negative value for all faces with surface IDs id_1 id_2 ... id_n. For example
using "-bls 12,1,10" would turn on BL grid generation from the boundary faces
with surface IDs 12, 1 and 10 and turn off BL grid generation from all other
boundary faces. This flag overrides any grid boundary condition set from the
input grid file. The commas between the surface IDs are required. This flag is
equivalent to using the following parameter options.
mbl=1
mrecm=3
mrecqm=3
BL_IDs=id_1,id_2,...,id_n
Note that the -bls flag also automatically selects the equivalent of -mmr_rec
to specify use of a MAX-MIN-Rratio criterion for local-reconnection. To turn
off the MAX-MIN-Rratio criterion use the "-bls ... -mma_rec" flags. The
-mma_rec must appear after the -bls ... flag.
-blgs n_1,id_1_1,id_2_1,...,id_n_1,...,n_m,id_1_m,id_2_m,...,id_n_m
Specify surfaces to be grouped for BL streamwise variation. Each group will be
treated as if it has an independent BL Streamwise variation will be determined
for each group independently. This flag will set the faces with surface IDs
id_1_1 id_2_1 ..., id_n_1 as group 1, ..., and faces with surface IDs id_1_m
id_2_m ... id_n_m as group m. Where m is the number of groups and n_1, ..., n_m
are the number of surface IDs in each respective group. For example using
"-blgs 3,12,1,10,2,7,8,1,11" would set boundary faces with surface IDs
12, 1 and 10 to be group 1, boundary faces with surface IDs 7 and 8 to be group
2 and boundary faces with surface ID 11 to be group 3. The commas between the
number of IDs in each group and between the surface IDs are required. This flag
is only applicable in cases with a BL grid (-bl, -bls flag), if the BL velocity
profile is assumed to be laminar or turbulent (-blf, -y+, mbltype=1, or
mbltype=2), and if the flow direction vector is specified (-vdir u v w). This
flag is equivalent to using the following parameter option.
BLG_IDs=n_1,id_1_1,id_2_1,...,id_n_1,...,n_m,id_1_m,id_2_m,...,id_n_m
-blints id_1,id_2,...,id_n
Set BL intersecting surface boundary condition on specified surfaces. The
surface grid will be regenerated with a intersecting BL for all intersecting
surfaces which are adjacent to a BL surface. This flag will set the grid
boundary condition to a value of 2 (denotes an intersecting surface ) for all
faces with surface IDs id_1 id_2 ... id_n. For example using
"-blints 12,1,10" would set all boundary faces with surface IDs 12, 1 and 10
to be intersecting surfaces. This flag overrides any grid boundary condition
set from the input grid file. If any other boundary faces were specified to be
intersecting surfaces within the input grid file they will be reset to standard
surfaces (a magnitude of one). The commas between the surface IDs are required.
This flag is only applicable in cases with a BL grid (-bl or -bls flag). This
flag is equivalent to using the following parameter options.
Int_IDs=id_1,id_2,...,id_n
-blcheck
Check BL parameters and input surface grid. If this option is selected then the
BL parameters and input surface grid will be checked and then the BL parameters
after automatic calculation will be output. No volume grid will be generated.
This flag is equivalent to using the following parameter option.
mblchki=1
-open
Generate BL region grid for an open domain. With an open domain only the BL
grid is generated and the domain is the generated BL region. No isotropic
region elements are generated with an open domain. The output grid includes a
new boundary surface for the exposed surface of the BL region with a boundary
surface face ID equal to the maximum ID plus 1. The default is to assume a
closed domain.
mopen=1
-revbl
Reverse BL normals for an open domain. With an open domain the normals remain
the same as those of the input surface mesh. With this option that direction
will be reversed. This option will also automatically set the open domain
option flag (-open).
mopen=1
mrevbl=1
CFD Boundary-Layer (BL) Grid Normal Spacing
===========================================
Parameters that control the spacing normal to BL surfaces can be set using the
turbulent/laminar flow option flags -Re and -blf, -du or -y+, -du+ and/or the
option flags -blds, -blr, -blrm, -blrend, -bldr and/or -bli. By default the
turbulent flow is assumed and the normal spacing parameters are set explicitly.
They can also be set automatically. In automatic mode the normal spacing
parameters, including growth and acceleration rates, are determined
automatically from either a laminar or turbulent flat-plate approximation. Also
on estimation of the BL thickness can be set and if so then the BL normal
generation will attempt to continue up to at least that thickness. Use of the
BL thickness can be turned on and set with the option flag -bldel bl_thickness
or turned off with the option flag -no_bldel. The automatic option can be turned
on or off with the option flags -blauto or -no_blauto. Also, use of either of
the option flags -blr or -bldr will turn off auto mode. If the initial normal
spacing is not set in the input grid file then one of the option flags -blds,
-blf, or -y+ must be used to set the initial normal spacing.
In automatic mode the typical options used are either -Re and -y+ for turbulent
flow or -Re and -blf for laminar flow. Further control on the normal spacing
is provided with the options -du+ for turbulent flow -du for laminar flow along
with the growth options -blrm and -blrend. As an alternative to the automatic
determination of the BL parameters, the normal spacing parameters can be set
explicitly using the option flags, -blds, -bli, -blr, -blrm, -blrend, and/or
-bldr,
During BL grid generation, point spacing normal to BL surfaces is controlled by
several parameters. Automatic mode for BL parameters is recommended as it helps
to insure that the BL region extends beyond an estimated BL thickness. Typical
usage is to set the Reynolds number per unit grid dimension using the -Re flag
and if needed the reference length in grid units with the -refx flag. The
reference length determines the actual Reynolds number used to calculate any BL
parameters based on a turbulent (or laminar) flow assumption. Also, the initial
normal spacing should be set using either the -y+ or -blds flag. In automatic BL
parameter mode the growth rates for BL normal spacing are calculated to achieve
a constant u+ velocity increment throughout the BL region. By default that value
is 1 and can be changed using the -du+ flag. The initial y+ value and u+
velocity increment can be changed independently. The initial y+ value only sets
the initial normal spacing.
Within the BL region the normal spacing for the first "iblri" layers is
determined using a constant growth rate, "cdfrbl". The values of "iblri" and
"cdfrbl" are set internally in automatic mode or in manual mode using the -bli
and -blr flags. After "iblri" layers the growth rate increases at an
acceleration rate specified by "dcdfrbl" up to a maximum growth rate of
"cdfrblm". Both of these parameters are set internally in automatic mode or in
manual mode using the -bldr and -blrm flags. The -blrm flag can be used in
automatic mode to limit the maximum growth rate. If it is then the internally
calculated value for the maximum growth rate is limited to be at or below the
value specified using the -blrm flag.
Additional BL layers are generated with normal spacing calculated as described
above. BL grid generation is terminated globally when the normal spacing is
near the isotropic spacing for the majority of the active BL surface points.
The parameters "cblend" and "cblnrend" control global termination. In
automatic mode, global termination is not used unless all active BL nodes are
above the estimated boundary layer thickness. Also, if BL thickness is specified
and BL grid generation continues beyond the estimated boundary layer thickness
then the growth rate is smoothly varied from the maximum value of "cdfrblm" to
the maximum of either the BL ending value of "cdfrblend" or the BL maximum
value of "cdfrblm". The BL growth rate ending value can be set using the
-blrend flag. BL generation also is terminated locally if points get too close,
element quality degrades, BLs merge, etc.
To help clarify and verify what the actual BL parameters are for a given case,
the option flag -blcheck can be used to check and list the BL parameters derived
from the input surface grid and command line options.
The following option flags are only applicable in cases with a BL grid (-bl or
-bls flag).
CFD Boundary-Layer Grid Normal Spacing (Turbulent or Laminar Flow Assumption)
=============================================================================
-Re reynolds_number
Specify reference Reynolds number per unit grid dimension to use in determining
the parameters that control spacing normal to BL surfaces. If the flow
direction vector is specified (|vx,vy,vz| > 0) then the local Reynolds number
is dependent upon the distance from the leading edge in the flow direction.
Otherwise the Reynolds number everywhere is based on the reference length. This
flag is equivalent to using the following parameter option.
blre=reynolds_number
-refx reference_x
Specify reference length in grid units. The reference length is used to
calculate BL parameters. If reference_x = 0 then the reference length is set to
the maximum physical length of all BL objects (and if the flow direction vector
is specified (|vx,vy,vz| > 0) then the maximum length in the direction of the
flow is used). If reference_x > 0 then the value of reference_x is used. This
flag is equivalent to using the following parameter option.
refx=reference_x
-blf fraction_of_laminar_bl
Specify fraction of laminar BL thickness used in determining the initial
spacing normal to BL surfaces. The specified value is also used to specify the
BL velocity increment to use in determining the parameters that control spacing
normal to BL surfaces. If this option flag is used then a laminar BL profile is
assumed. This flag is equivalent to using the following parameter options.
mbltype=1
blyp=fraction_of_laminar_bl
-y+ y+_value
Specify y+ for a turbulent BL to use in determining the initial spacing normal
to BL surfaces. The specified y+ value also determines the BL velocity
increment to use in calculating the parameters that control spacing normal to
BL surfaces. In the linear region of a turbulent BL u+ = y+ and the u+ velocity
increment is equal to the initial normal spacing y+ value. If this option is
used then a turbulent BL velocity profile is assumed. This flag is equivalent
equivalent to using the following parameter options.
mbltype=2
blyp=y+_value
-du du_value
Specify normalized velocity increment (velocity increment normalized with the
velocity at the edge of the BL) for a laminar BL to use in determining the
spacing normal to BL surfaces. If the velocity increment is not specified then
it is set based on the initial normal spacing. If the velocity increment is set
and the initial normal spacing is not set then the initial normal spacing will
be calculated based on the velocity increment. If this option is used then a
laminar BL velocity profile is assumed. This flag is equivalent to using the
following parameter options.
mbltype=1
bldup=du_value
-du+ du+_value
Specify u+ velocity increment (velocity increment normalized with the friction
velocity) for a turbulent BL to use in determining the spacing normal to BL
surfaces. If the u+ velocity increment is not specified then it is calculated
based on the initial normal spacing. If the u+ velocity increment is set and
the initial normal spacing is not set then the initial normal spacing will be
calculated based on the u+ velocity increment. If this option is used then a
turbulent BL velocity profile is assumed. This flag is equivalent to using the
following parameter options.
mbltype=2
bldup=du+_value
-vdir u v w
Specify the flow direction with an assumed laminar or turbulent BL velocity
profile. Where u, v and w are the x, y and z components of the flow direction
vector. If the flow direction vector is specified and has a non-zero magnitude
then a streamwise variation in the BL spacing and thickness is automatically
determined. This flag is equivalent to using the following parameter options.
vx=u
vy=v
vz=w
-blauto
Automatically calculate growth rate parameters or BL thickness. The default is
to explicitly input these values. This flag is equivalent to using the
following parameter options.
mblauto=1
-no_blauto
Do not automatically calculate growth rate parameters or BL thickness. This is
the default behavior. This flag is equivalent to using the following parameter
options.
mblauto=0
-no_bldel
Ignore BL thickness specified in the input file or calculated from a laminar
or turbulent profile. In this case the BL normal generation will attempt
continue until the normal spacing is close to the nearby isotropic value. This
is the default behavior. This flag is equivalent to using the following
parameter option.
deldef=-1
CFD Boundary-Layer Grid Normal Spacing
======================================
-blreseti
Reset initial normal spacing and/or BL thickness values set in the input
surface grid file with those determined from the command line arguments (such
as -y+, -blds, -bldel, etc).
mblreseti=1
-blrm maximum_growth_ratio
Specify maximum allowable growth rate for BL normal spacing. The normal
spacing grows geometrically. The growth rate also increases geometrically.
The maximum allowable value of the normal spacing growth rate is equal to
maximum_growth_ratio. Use of this option will limit growth rates determined
using the automatic calculation of growth rate parameters. This flag is
equivalent to using the following parameter options.
cdfrblm=maximum_growth_ratio
-blrend end_growth_ratio
Specify ending growth rate for BL normal spacing. The normal spacing growth
rate is set to the ending value if the thickness of the BL region extends
beyond the specified BL thickness. The value of the ending growth rate is
limited to be greater than or equal to the maximum allowable BL growth rate.
This option is only applicable if the BL thickness is explicitly set or if the
automatic calculation of growth rate parameters is used. This flag is using the
equivalent to using the following parameter options.
cdfrblend=end_growth_ratio
-bli number_of_layers
Specify number of constant BL normal spacing layers adjacent to the BL surface.
BL normal spacing growth is applied after the specified number of constant
spacing layers. If growth rate parameters are calculated automatically and not
explicitly set then the number of constant spacing layers is set internally.
This flag is equivalent to using the following parameter options.
iblri=number_of_layers
-bldel thickness
Specify BL thickness to be the value of normal_thickness. If the BL thickness
is specified or set otherwise the BL normal generation will attempt to continue
beyond that thickness. There is no default value for the BL thickness. This
flag is equivalent to using the following parameter option.
deldef=thickness
-bldelmax
Set BL thickness equal to the maximum BL thickness required for the entire BL
region to reach maximum local normal spacing (cblmnr multiplied by the local
isotropic length scale). Note that this option flag will override the value
set by other options (-bldel, -blauto, etc). This flag is equivalent to using
the following parameter option.
mbldelmax=1
-blds normal_spacing
Specify initial normal spacing to be the value of normal_spacing. There is no
default value for the initial normal spacing. This flag is equivalent to using
the following parameter option.
dsdef=normal_spacing
-blr initial_growth_ratio
Specify initial growth in BL normal spacing. The normal spacing grows
geometrically at a rate which is initially equal to the value of
initial_growth_ratio. The growth rate increases geometrically from the initial
growth rate value (see -bldr). Use of this option will override the automatic
calculation of growth rate parameters. This flag is equivalent to using the
following parameter options.
mblauto=0
cdfrbl=initial_growth_ratio
-bldr growth_ratio_multiplier
Specify multiplier used for determining BL normal spacing growth. The normal
spacing grows geometrically. The geometric growth rate also increases
geometrically at a rate equal to the value of growth_ratio_multiplier. Use of
this option will override the automatic calculation of growth rate parameters.
This flag is equivalent to using the following parameter options.
mblauto=0
dcdfrbl=growth_ratio_multiplier
-bldsm normal_spacing_multiplier
Specify multiplier to modify initial spacing normal to BL surfaces. The initial
normal spacing calculated, set by option parameter, or set with the input grid
is multiplied by this multiplier. This flag is equivalent to using the
following parameter option.
dsmul=normal_spacing_multiplier
Structured-Layer (SL) Grid
==========================
-sl
Generate a structured-layer grid (SL) grid with right-angle isotropic elements
from all boundary faces with a grid boundary condition flag less than zero. The
grid boundary condition flag can be set in the input grid file. If it is not
set in the input grid file, then all boundary faces are set to a negative grid
boundary condition value unless set otherwise using the -sls or equivalent
flag. This flag is equivalent to using the following parameter options.
mbl=2
-sls id_1,id_2,...,id_n
Generate a SL grid with isotropic elements from specified surfaces. Set the
grid boundary condition to a negative value for all faces with surface IDs
id_1 id_2 ... id_n. For example using "-sls 12,1,10" would turn on SL grid
generation from the boundary faces with surface IDs 12, 1 and 10 and turn off
SL grid generation from all other boundary faces. This flag overrides any grid
boundary condition set from the input grid file. The commas between the surface
IDs are required. This flag is equivalent to using the following parameter
options.
mbl=2
BL_IDs=id_1,id_2,...,id_n
-slc
Combine tetrahedral elements within SL regions to form pentahedra (prismatic
and pyramid). With this option an output grid file type that supports
pentahedra should be specified. This flag is only applicable in cases with a SL
grid (-sl or -sls flag). This flag is equivalent to using the following
parameter option.
mblelc=1
-slc2
Combine tetrahedral elements within SL regions to form pentahedra (prismatic
and pyramid) and hexahedra. With this option an output grid file type that
supports pentahedra and hexahedra should be specified. This flag is only
applicable in cases with a SL grid (-sl or -sls flag). This flag is equivalent
to using the following parameter option.
mblelc=2
-slints id_1,id_2,...,id_n
Set SL intersecting surface boundary condition on specified surfaces. The
surface grid will be regenerated with a intersecting SL for all intersecting
surfaces which are adjacent to a SL surface. This flag will set the grid
boundary condition to a value of 2 (denotes an intersecting surface ) for all
faces with surface IDs id_1 id_2 ... id_n. For example using
"-slints 12,1,10" would set all boundary faces with surface IDs 12, 1 and 10
to be intersecting surfaces. This flag overrides any grid boundary condition
set from the input grid file. If any other boundary faces were specified to be
intersecting surfaces within the input grid file they will be reset to standard
surfaces (a magnitude of one). The commas between the surface IDs are required.
This flag is only applicable in cases with a SL grid (-sl or -sls flag). This
flag is equivalent to using the following parameter options.
Int_IDs=id_1,id_2,...,id_n
-slf fraction_of_spacing
Set initial normal spacing for SL grid generation to the local isotropic
boundary surface face spacing multiplied by a fraction_of_spacing. This flag is
equivalent to using the following parameter option.
cdfslm=fraction_of_spacing
-slr growth_ratio
Specify growth in SL normal spacing. This flag is equivalent to using the
following parameter options.
cdfrsl=growth_ratio
Specified Normal Spacing (SNS) Grid
===================================
-sns
Generate a specified normal spacing (SNS) grid with right-angle elements from
all boundary faces with a grid boundary condition flag less than zero. The grid
boundary condition flag can be set in the input grid file. If it is not set in
the input grid file, then all boundary faces are set to a negative grid
boundary condition value unless set otherwise using the -snsbc or equivalent
flag. This flag is equivalent to using the following parameter options.
mbl=-1
-snsbc id_1,id_2,...,id_n
Generate a SNS grid with right-angle elements from specified surfaces. Set the
grid boundary condition to a negative value for all faces with surface IDs
id_1 id_2 ... id_n. For example using "-snsbc 12,1,10" would turn on SNS grid
generation from the boundary faces with surface IDs 12, 1 and 10 and turn off
SNS grid generation from all other boundary faces. This flag overrides any grid
boundary condition set from the input grid file. The commas between the surface
IDs are required. This flag is equivalent to using the following parameter
options.
mbl=-1
BL_IDs=id_1,id_2,...,id_n
-snsc
Combine tetrahedral elements within SNS regions to form pentahedra (prismatic
and pyramid). With this option an output grid file type that supports
pentahedra should be specified. This flag is only applicable in cases with a
SNS grid (-sns or -snss flag). This flag is equivalent to using the following
parameter option.
mblelc=1
-sns2
Combine tetrahedral elements within SNS regions to form pentahedra (prismatic
and pyramid) and hexahedra. With this option an output grid file type that
supports pentahedra and hexahedra should be specified. This flag is only
applicable in cases with a SNS grid (-sns or -snss flag). This flag is
equivalent to using the following parameter option.
mblelc=2
-snsints id_1,id_2,...,id_n
Set SNS intersecting surface boundary condition on specified surfaces. The
surface grid will be regenerated with a intersecting SNS for all intersecting
surfaces which are adjacent to a SNS surface. This flag will set the grid
boundary condition to a value of 2 (denotes an intersecting surface ) for all
faces with surface IDs id_1 id_2 ... id_n. For example using
"-snsints 12,1,10" would set all boundary faces with surface IDs 12, 1 and 10
to be intersecting surfaces. This flag overrides any grid boundary condition
set from the input grid file. If any other boundary faces were specified to be
intersecting surfaces within the input grid file they will be reset to standard
surfaces (a magnitude of one). The commas between the surface IDs are required.
This flag is only applicable in cases with a SNS grid (-sns or -snss flag).
This flag is equivalent to using the following parameter options.
Int_IDs=id_1,id_2,...,id_n
-snsi n_1,id_1_1,id_2_1,...,id_n_1,...,n_m,id_1_m,id_2_m,...,id_n_m
Specify surface IDs for SNS spacing groups. Spacing groups are used to set SNS
normal spacing. This flag will set the faces with surface IDs id_1_1 id_2_1
..., id_n_1 as group 1, ..., and faces with surface IDs id_1_m id_2_m ...
id_n_m as group m. Where m is the number of groups and n_1, ..., n_m are the
number of surface IDs in each respective group. The normal spacing distribution
specified for each group will apply to these groups. The number of spacing
groups, m, must be the same as the number of groups used to specify the normal
spacing. If the -snsi flag is not used then one spacing group that contains all
applicable surface IDs is assumed. For example, using "-snsi 2,3,5,3,6,2,4"
will set two groups, all faces with surface IDs 3 and 5 will be part of group 1
and all faces with surface IDs 6, 2 and 4 will be part of group 2. Note that
a surface ID can be specified that is not a SNS generating surface and doing so
will not change it to a SNS generating surface. The commas between the surface
IDs are required. This flag is equivalent to using the following parameter
options.
SNS_IDs=n_1,id_1_1,id_2_1,...,id_n_1,...,n_m,id_1_m,id_2_m,...,id_n_m
-snss s_1_1,s_2_1,...,s_n_1,...,s_1_m,s_2_m,...,s_n_m
Set specified normal spacing distribution. The specified normal spacing
distribution must be set to generate a SNS grid. If multiple spacing groups are
specified using the -snsi flag then the same number of groups must be used in
the specified normal spacing. If only one group is set or assumed then the
specified normal spacing applies to all SNS generating surfaces. This flag sets
the normal spacing distribution to s_1_1 s_2_1 ... s_n_1 for group 1, ..., and
to s_1_m s_2_m ... s_n_m for group m. Where m is the number of groups. Each
normal spacing group must start at a value of 0 for s_1_i (group i) and must
be ordered in increasing value. The number of normal spacing groups (number of
zero entries in vector SNS) must be the same as that for the -snsi flag if more
than one group is specified. For example, using "0,.1,.2,.3,.4,0,.05,.1,.2,.5"
will set two groups with a normal spacing distribution for group 1 set to
0,.1,.2,.3,.4 and for group 2 set to 0,.05,.1,.2,.5. The commas between the
normal spacing entries are required. This flag is equivalent to using the
following parameter options.
mbl=-1
SNS=s_1_1,s_2_1,...,s_n_1,...,s_1_m,s_2_m,...,s_n_m
-snsr growth_ratio
Specify normal spacing growth rate in SNS transition zone. The geometric growth
rate is set to cdfrsns in the transition zone between the region where normal
spacing is specified and the isotropic region. If cdfrsns=1 then there will be
no transition zone and outside the region where normal spacing is specified the
elements will immediately transition to isotropic tets. This flag is only
applicable in cases with a SNS grid (-sns or -snss flag). This flag is
equivalent to using the following parameter option.
cdfrsns=growth_ratio
Transparent and Intersecting Surface Grid Boundary Condition Flags
==================================================================
-setbc
Automatically identify transparent and planar surfaces. If a surface contains a
face with a free edge then the grid boundary condition flag for all faces on
that surface will be set to an transparent surface. A surface is defined as a
set of connected faces that all have the same boundary surface ID flag.
This option flag will also automatically identify planar surfaces that might
intersect a BL/SL/SNS region. If a surface is planar and is not a BL/SL/SNS
generating surface then the grid boundary condition flag for all faces on that
surface will be set to an intersecting surface. A planar surface is defined as
a set of connected faces that all have the same boundary surface ID flag and
surface normal vector.
This flag is equivalent to using the following parameter option.
msetbc=1
-setbc2
Same as the -setbc option flag except any transparent surfaces found will be
converted to source nodes and those surface faces will not be included in the
final volume grid. This flag is equivalent to using the following parameter
option.
msetbc=2
Boundary Surface Reconnection Flag
==================================
-brecs id_1,id_2,...,id_n
Set boundary surface reconnection flag on for specified surfaces. Boundary
surface grid reconnection will be allowed in all directions on all specified
surfaces. This flag sets the boundary surface reconnection flag to a value of 0
(denotes reconnection allowed in all directions) for all faces with surface IDs
id_1 id_2 ... id_n and set the flag to a value of 7 (denotes no reconnection
allowed in any direction) for all other faces. For example using
"-brecs 12,1,10" would allow reconnection on all boundary faces with surface
IDs 12, 1 and 10 and turn off reconnection on all other boundary faces. This
flag will override the boundary surface reconnection flag set from the input
grid file for only the faces specified. The commas between the surface IDs are
required. This flag is equivalent to using the following parameter options.
Rec_IDs=id_1,id_2,...,id_n
Set Volume Element ID Option
============================
-set_vol_id
Allocate and set output file volume element id to a unique value for each solid
in the volume grid. The default is to not allocate the volume element id and
use dummy values. In the case of file conversion (-convert) then the default
is to use the values found in the input file. This flag is equivalent to using
the following parameter options.
Set_Vol_ID_Flag=1
TAGS File Option
================
-tags
Search for a tags file named case_name.tags and if found read it and set
surface grid properties. Values for boundary surface grid BC and boundary
surface reconnection flag that are specified in a TAGS file will be used
instead of those specified in the input surface grid file.
Also, BL normal spacing, and BL thickness that are specified in a TAGS file
will be used instead of those specified in the input surface grid file.
This flag is equivalent to using the following parameter options.
Tags_Data_File_Flag=1
Grid Quality Output
===================
-q qindex
Generate volume grid quality data for one or more selected quality measures.
The default is to generate only volume element angle data. This flag is
equivalent to using the following parameter option.
GQ_Vol_Measure_Flag=value
See the description of GQ_Vol_Measure_Flag in the PARAMETER OPTIONS section for
more information.
-qall
Generate volume grid quality data for all quality measures. The default is to
only generate angle data. This flag is equivalent to using the following
parameter option.
GQ_Vol_Measure_Flag=15
-qnone
Do not generate any volume grid quality data. The default is to generate angle
data. This flag is equivalent to using the following parameter option.
GQ_Vol_Measure_Flag=0
-qs qindex
Generate boundary surface grid quality data for one or more selected quality
measures. The default is to not generate boundary surface data. This flag is
equivalent to using the following parameter option.
GQ_Surf_Measure_Flag=value
See the description of GQ_Surf_Measure_Flag in the PARAMETER OPTIONS section
for more information.
-qsall
Generate boundary surface grid quality data for all quality measures. The
default is to not generate boundary surface data. This flag is equivalent to
using the following parameter option.
GQ_Surf_Measure_Flag=15
-qsnone
Do not generate any surface grid quality data. The default is to generate angle
data. This is the default. This flag is equivalent to using the following
parameter option.
GQ_Surf_Measure_Flag=0
Post Processing
===============
If the input grid contains any field elements then the code will automatically
skip initial triangulation and field point creation and go on to final quality
improvement.
-qstat
Generate grid quality statistics for a previously generated grid. The input
grid will not be modified and no output grid file will be written. This flag is
equivalent to using the following parameter options.
Program_Flag=-6
-convert
Convert file type and/or format for an existing grid file. The input grid file
will not be modified and no grid quality output will be generated. This flag is
equivalent to using the following parameter options.
Program_Flag=0
GQ_Vol_Measure_Flag=0
GQ_Surf_Measure_Flag=0
Initial Triangulation
======================
-igen
Generate only an initial volume triangulation of the boundary points with all
boundary surface triangles recovered. No field points will be generated unless
required for boundary recovery. This flag is equivalent to using the following
parameter options.
ngen=0
nqual=0
mqrgen=0