The following sections of this chapter are:
convertgrid is a tool that enables many editing operations on
a FENSAP format grid.
Operations:
File format conversion (ASCII, binary, C3D solid)
General grid statistics
Grid order optimization
Scaling, rotation, translation
Node periodicity correction
Boundary condition operations: renumbering, detection of missing facets
Volume operations: splitting
Cell operations
Note: For a complete and fully up-to-date command reference, use convertgrid -h.
Table 15.4: Convertgrid
| convertgrid [SOURCEGRID] [DESTINATIONGRID] [OPTIONS] |
Format of the |
Table 15.5: Options
| -d |
Diagnostic mode - Does not write output file but lists the solution content (reference values, solution datafields, zones and boundary conditions). |
Table 15.6: Output File Formats
| -ascii |
Writes text format grid (default=binary, for speed). File output format is binary, unless -ascii is specified. |
| -c3d |
Writes a C3D format grid (solid domains). |
| -cart |
Writes a grid in Cartesian coordinates. |
| -cyl |
Writes a grid in cylindrical coordinates. |
| -solid |
Writes a solid domain grid. |
Table 15.7: Input File Format
| -readc3d |
Reads a C3D format grid. |
| -rotx |
Specifies the X axis of rotation, if any. Required for some features. |
| -roty |
Specifies the Y axis of rotation, if any. Required for some features. |
| -rotz |
Specifies the Z axis of rotation, if any. Required for some features. |
Table 15.8: Stats
| -d |
Printout grid stats and end (size, boundary conditions, cell types). |
| -dd |
Outputs extra read info. |
Table 15.9: Grid Scaling/Operations
| -factor=VALUE |
Scale the nodes coordinates by VALUE factor. |
| -factor=X,Y,Z |
Scales the X,Y,Z coordinates by VALUE factor. |
| -translate=X,Y,Z |
Scales the grid by the specified vector. |
| -translatePost |
Translates after all other operations (on all materials). |
| -rotate[X,Y,Z]=angle |
Rotates the grid along X,Y,Z axis, by the specified angle (degrees). |
Table 15.10: Optimization
| -optimize |
Reorders the node numbering with the RCM algorithm. |
| -optimize2 |
Reorders the node numbering with the Octree algorithm. |
Table 15.11: Boundary Condition Operations
| -renameBC=OLD,NEW |
Renumbers the specified boundary condition to NEW. |
| -renameBC=OLD,NEW,EQUATION |
Same as -renameBC but only where EQUATION is true. |
| -detectBC=BC |
Detects missing boundary facets on the grid and assigns them the identifier boundary condition. |
| -fixBC |
Detects and remove duplicate facets. |
| -filterInternalBCs |
Removes boundary condition surrounded by two volume elements, except actuator disks or heater pads. |
Table 15.12: Volume Operations
| -splitVolumes |
Writes OUTPUT.X grids, one for each volume. |
| -splitMaterials |
As -splitVolumes, but using material IDs as volumes. |
| -splitSoln=FILENAME |
In -splitVolumes mode, can split a solution file. |
| -splitHFlux=FILENAME |
In -splitVolumes mode, can split a hflux.dat file. |
| -splitShear=FILENAME |
In -splitVolumes mode, can split a surface.dat file. |
| -splitJoin=V1,V2 |
Volume 2 will be merged to Volume 1. |
| -splitSkip=V |
Discards the volume V when working on multiple domains. |
| -mergeBC=BC1,BC2 |
Merges nodes of node-matching surfaces. |
Table 15.13: Material Operations
| -renameMat=OLD,NEW |
Renumbers the specified material ID to NEW. |
| -renameMat=OLD,NEW,EQUATION |
Same as -renameMat but where EQUATION is true. |
Table 15.14: Periodicity Operations
| -periodic[=tolerance] |
Sets periodic flags on 4100, 4200, 4300s boundary condition, must be node-matching; also permits to double-check the accuracy of a grid periodicity. |
| -notperiodic |
Removes periodicity in the output grid. |
| -periodicZone=4*** |
For -periodic, specifies the symmetry boundary condition number that is periodic. |
| -periodicPlanes=tolerance |
Optionally used with -periodic, to refine the tolerance of a point on a plane. |
| -periodicTranslation=X,Y,Z |
Specifies the translation vector. |
| -periodicClipPlane=[X|Y|Z],low,hi |
Clips the periodic nodes on the given planes. Used with -periodic. |
| -periodicRotational=X/Y/Z,ANGLE |
Specifies the axis of rotation and angle in DEG. |
| -periodicFix |
For already periodic grids, will increase the periodic plane accuracy (periodicTranslation/Rotational argument required). |
| -clearPeriod=BC,BC,... |
Removes periodicity on specified boundary condition list. |
| -prBC=BC1,BC2 |
Used with -periodicRotational/Translation, specifies boundary condition pairs to match. Boundary conditions are erased. |
Table 15.15: Example Commands
| convertgrid grid_bin grid_asc -ascii |
Convert a grid to ASCII Format. |
| convertgrid grid_asc grid_opt -optimize2 |
Convert a grid to binary format, and reorder the node numbering for better performance. Nodal solutions, heat fluxes and so on are not useable with the reordered file as the node and facet order of the output file is different. |
| convertgrid grid_in grid_m -factor=0.0254 |
Scale a grid from inches to meters. |
| convertgrid grid_in grid_out -renameBC=2002,2000 -renameBC=2003,2000 |
Renumber a boundary condition identifier. (All facets of boundary condition 2002 and 2003 renamed to 2000). |
| convertgrid grid_in grid_out -renameBC=2000,2001,"Y>0" |
Renumber a boundary condition identifier from a geometrical condition. (All facets of boundary condition 2000 for which the centroid is over Y = 0 coordinate will be renumbered as 2001). |
| convertgrid grid_multi grid_part -splitVolumes |
Split a multi-volume grid into separate grids, grid_part.1 and grid_part.2 would be written. |
| convertgrid grid_multi grid_part -splitVolumes -splitSoln=grid_multi.soln -splitHFlux=grid_multi.hflux -splitShear=grid_multi.surface |
Split a multi-volume grid and solution files into separate grid/solution files. (In addition to grid_part.X, grid_part.X.soln/hflux/surface will be written). |
Table 15.16: Example Commands Continued
|
To add rotational periodicity onto a grid lacking periodicity information:
| |
| convertgrid grid_orig grid_bcsplit -renameBC=4000,4001,"THETA>0" -rotx |
The two boundary conditions are now useable for periodicity node detection, which is a known 45 degrees rotation along the X axis. |
| convertgrid grid_bcsplit grid_periodic -periodicRotational=X,45 -prBC=4000,4001 |
FENSAP requires a rotational periodic grid (or non-axis-aligned translational periodic grid) to have periodic nodes, but no boundary condition facets (or a boundary condition 5000). |
| convertgrid grid_orig grid_bcsplit -renameBC=4000,5000 -renameBC=4001,5001 |
Renames the two temporary symmetry plane boundary conditions 4000 and 4001 to their final identifier 5000 and 5001 (periodic boundary conditions). |
The Ansys Fluent case and solution file (.cas(.h5) and .dat(.h5)) can easily be converted to a FENSAP grid and airflow solution format.
This operation is usually done within FENSAP-ICE by selecting a .cas(.h5) file as the grid input file. The import panels will provide the means to fine-tune the boundary conditions, reference conditions and solution field association.
The fluent2fensap process is fully automated and normally
does not require adjustments.
Reference values are extracted from the Fluent configuration and written in the solution file header. The values in the solution file header are required only for:
Viewmerical Postprocessing:
The calculation of the pressure coefficient requires
PINF,TINF,VELINF. The calculation of the airflow Mach number requiresRGAS,GAMMA. The calculation of the relative velocity components requireRPMX,RPMY,RPMZ.CHT3D Anti-Icing:
Requires
RGAS,GAMMA,VELINF.Note: If the reference velocity value selected by
fluent2fensapis not correct, it must be reset with the proper value, otherwise CHT3D will not be able to compute the correct surface temperature and heat fluxes.
| fluent2fensap INPUT.cas OUTPUT [parameters] |
Reads from the Fluent case file INPUT.cas (and optionally INPUT.dat, if in the same location), and write to the OUPUT prefix (OUTPUT.grid, OUTPUT.soln, etc.). |
Table 15.17: Options
| -d |
Diagnostic mode. Does not write the output file but list its content (reference values, solution datafields, zones and boundary conditions). |
Table 15.18: Icing Options
| -roughness=FILE |
If Fluent was configured with a roughness profile,
typically obtained from ICE3D beading model in a previous
FENSAP-ICE computation, it is required to apply the same
roughness value in the airflow solution file converted from
Fluent format. This argument permits to specify a
roughness.dat file, with the
roughness distribution. The roughness values will be
inserted in the output airflow solution file written by
A roughness.dat file related to the
node number and ordering in the grid. If the Fluent grid
has been remeshed, or reordered, the
roughness.dat of the previous shot cannot be
used as-is, and will need to be re-interpolated on the new
grid: Use then the |
Table 15.19: Output Files
| -nosoln |
Will not read a .dat(.h5) file nor write a soln file. |
| -ascii |
Output FENSAP grid written in ASCII (default is binary). |
| -solid |
Write a solid grid (for use with C3D). |
| -imat |
Write a multi-material grid (for use with FENSAP/DROP3D and multiple domains). This is automatic if the Fluent grids have more than one cell section. |
Table 15.20: Multi-Zone Options
| -materials=ZONE,ZONE,ZONE |
Optional. Provide a specific order for the material IDs. |
Table 15.21: Solution Options
| -rotVX=RPM |
Convert a relative-frame solution to absolute. |
| -rotVY=RPM |
Convert a relative-frame solution to absolute. |
| -rotVZ=RPM |
Convert a relative-frame solution to absolute. |
| -rotabs |
Indicate the solution is absolute frame. Use –rotVX/-rotVY/-rotVZ to specify the rotation speed which will be stored in the solution header (used for post-processing). |
Table 15.22: Boundary Conditions
| wall-6:2001 wall-7:2002 "inlet with spaces":1001 non-useful-internal-wall:0 |
Fluent boundary conditions are matched to suitable FENSAP boundary condition types and identifiers. The automatic behavior can be overloaded by using the ZoneName:BC syntax. Use quotes for zone names with multiple words separated by spaces. If the boundary condition identifier 0 is chosen, the facet zone will not be written. Refer to Boundary Conditions for details on boundary condition identifiers. |
The reference values automatically detected from Fluent configurations can
be replaced on the command line by using the VAR=VALUE
syntax.
Table 15.23: The Following Values are Important
| VELINF |
Reference velocity (m/s) |
| TINF |
Reference static temperature (K) |
| PINF |
Reference static pressure (Pa) |
Table 15.24: The Following Values are Optional
| LENINF |
Reference length (m) |
| VELX, VELY, VELZ |
Components of the reference velocity (m/s) |
| RPMX, RPMY, RPMZ |
Rotation speed (rpm) |
Table 15.26: Variables Continued
| MACHINF, HINF, XKEINF, RHOINF, P0INF, ZMUINF, REINF, PRINFND, ENTRINF |
Variables computed automatically from the other variables above. |
Table 15.27: fluent2fensap Commands
| fluent2fensap cht_ext.cas cht_ext |
Writes chg_ext.grid (and cht_ext.soln, cht_ext.hflux, cht_ext.surface, if there is a check_ext.dat in the same directory). |
| fluent2fensap cht_ext.cas cht_ext TINF=265.3 |
Same as above, however the reference temperature read from the file is adjusted to 265.3 K. |
| fluent2fensap cht_solid.cas cht_solid wall-6:6100 -solid |
Writes the output file in a format compatible with C3D. The wall-6 surface is converted to a heater boundary condition (range 6000-6999). |
This tool permits to convert a FENSAP grid into the Fluent grid format. The file will contain only the grid and boundary condition types, no solver settings are written.
Important: Some grids with periodicity will be converted to a Fluent file with invalid shadow zone surfaces, and Fluent might fail to read them. In such a case, the suggested approach is:
Convert the grid using the
–noperiodoption or prepare an input grid withconvertgrid INPUT OUTPUT -notperiodic.Rotational periodicity: Operations required in Fluent after the conversion.
For each cell zone: Set-up the rotation axis.
For each facet periodic zone: Set up the periodicity type as rotational.
Translational periodicity : No operation required.
Note: A Check Mesh operation in Fluent can confirm the grid periodicity is correctly set up.
Table 15.28: General Commands
| fensap2fluent grid soln -out=OUT [options] |
Read the FENSAP format grid and airflow solution soln, and writes to OUT.cas and OUT.dat. |
| fensap2fluent grid -nosoln -out=OUT [options] |
Grid-only conversion. Reads the file grid, and writes to OUT.cas. |
Table 15.29: Input File Options
| -solid |
Reads a C3D solid grid file format. |
| -read=FILE.cas |
Reads a reference case file, some options (solver settings, zone numberings) will be copied in the new output .cas(.h5) file. This might result in an incomplete Fluent configuration. |
| -modifyNodes=FILE.cas |
Reads a reference case file and writes it as output, with the only modification being the XYZ coordinates of the nodes, read from the input FENSAP grid. This is used to displace the nodes after ICE3D ALE grid displacement. |
| -h5 | Writes a .cas.h5 file. |
Table 15.30: Output File Options
| -ascii |
Fluent file will be written in ASCII. |
| -noperiod |
Disable periodicity writing. |
cfx2fensap is a tool introduced in FENSAP-ICE 2015R1.0 to
enable automatic conversion from CFX .res format to
FENSAP grid and airflow solution formats. General usage is similar to
fluent2fensap.
This operation is usually done within FENSAP-ICE, by selecting the .res file as the grid input file for a run. The import panels will allow fine-tuning of the boundary conditions, reference conditions and solution field associations. In FENSAP-TURBO simulations, multi-row grids can be separated and automatically configured in FENSAP-ICE.
Note: CFX must be installed on the machine where
cfx2fensap is launched, and the
cfx5cmds tool is accessible, either via a global
execution path, or the command line below.
- -cfxPath=/path/
Used to indicate the path of the bin/ subdirectory of the current installation of CFX.
Alternatively, if a CCL appears alongside the input .res file, CFX is not required to reside on the execution machine. (FILE.ccl alongside FILE.res) The CCL can be generated in the following way.
From CFX-Pre:
→ → → select all objects.
- cfx5cmds - read -definition INPUT.res -text INPUT.ccl
Generates a CCL from a command line.
cfx2fensap INPUT.res OUTPUT [options]Reads from the CFX solution file INPUT.res, and writes to the OUTPUT prefix (OUTPUT.grid, OUTPUT.soln, etc.).
Table 15.31: Output Options
| -zone=N |
Extract a subzone of the grid (1-N), only, for example, a turbofan stage, or a single material. |
| -split |
Write all subzones of the grid to different OUTPUT.ZONENAME files. Used for turbo-fan grid, separated in multiple rows. |
| -hflux -shear |
Write hflux and shear stress facet-based files. |
| -solid |
Write a solid grid (for use with C3D). |
| -notperiodic |
Write a grid without considering its periodicity (translational or rotational). |
| -roughness=FILE |
Specify a roughness.dat file from a previous ICE3D execution on this grid. The roughness data will be appended to the converted airflow solution in FENSAP format. This is done automatically at each shot (except the first) of a Multishot-CFX simulation. |
Boundary Conditions:
CFX boundary conditions are matched to suitable FENSAP boundary
condition type and identifiers. The automatic behavior can be overloaded by
using the ZoneName:BC syntax. Use quotes for zone names
with multiple words separated by spaces.
If the boundary condition identifier 0 is chosen, the facet zone will not be written. Refer to Boundary Conditions for details on FENSAP boundary condition identifiers.
Table 15.32: Boundary Condition Identifier
| Wall1:2001 Wall2:2002 "inlet with spaces":1001 non-useful-internal-wall:0 |
Boundary Condition Identifier at 0. |
Reference Conditions
The detection is done automatically from the CFX settings and flow solution, but should be reviewed in the output log.
The reference velocity and reference temperature are the average quantities of the airflow velocity and static temperature distributions at the inlet of your CFD solution. For multi-domain solution files:
in -zone-N mode, the reference values are computed at the inlets of the selected domain,
while in default or -split mode, the reference conditions are computed at the global inlets of the multi-domain.
The reference pressure is taken from the Reference Pressure field located in the Domain panel of CFX as long as its value is non-zero. If the Reference Pressure in CFX is set to zero, the reference pressure used during conversion is set to 101,325 Pa.
CHT3D/CFX requires proper reference condition values in the FENSAP solution file.
Refer to fluent2fensap.
The automatic conversion of a FENSAP grid file to CFX format is not
natively supported. Instead, the FENSAP file is to be converted to a Fluent file
using fensap2fluent and then the new Fluent mesh is read by
CFX-Pre.
An existing CFX-Pre configuration can be updated from a new, compatible, mesh if the original mesh is overwritten and the → option is chosen.