### 9.1.3. Supported Mesh File Types

Mesh file types supported by CFX-Pre are:

- ANSYS Meshing Files
- CFX-Mesh Files
- CFX-Solver Input files
- ICEM CFD Files
- ANSYS Files
- Fluent Files
- CGNS Files
- CFX-TASCflow Files
- CFX-4 Grid Files
- CFX-BladeGenPlus Files
- PATRAN Neutral Files
- IDEAS Universal Files
- GridPro/az3000 Grid Files
- NASTRAN Files
- Pointwise Gridgen Files
- User Import

Note: Users of the DesignModeler, Meshing application, and ANSYS CFX products should refer to Named Selections and Regions for ANSYS CFX in the Meshing User's Guide for important information about region definitions.

#### 9.1.3.1. ANSYS Meshing Files

ANSYS Meshing files of the form .cmdb and .dsdb can be imported.

Note:

- You must have ANSYS Workbench installed in order to import ANSYS Meshing files (.cmdb and .dsdb) into CFX-Pre or CFD-Post.

- CFX-Pre does not support importing meshes from `.cmdb` files generated by the Meshing application prior to Release 11.0.

- When CFX-Pre is run outside of ANSYS Workbench, and when importing or loading .cmdb or .dsdb files into CFX-Pre, meshes generated with the "Assembly Mesh" method cannot be read.

You can specify an assembly prefix. For details, see Common Import Options.

There are import settings that are specific to ANSYS Meshing files.

The Model(s) To Read setting defaults to `All`, which specifies that all models are to be imported from the ANSYS Meshing file. However, if you load a `cmdb/dsdb` file that has multiple models in it, you can specify which models to load.

Note: You must click next to the Model(s) To Read setting before the other models will appear.

##### 9.1.3.1.1. Named Selections

Named selections are aliases for collections of regions. When importing a mesh from an ANSYS Meshing file, you can preserve these named selections based on where they were created:

- CFX Mesh Names for regions defined in CFX-Mesh.

- Simulation Names for named selections generated in the Mechanical application and ANSYS Workbench Meshing.

- Symmetry Names for named selections of 2D symmetry and periodic regions generated in the Mechanical application and ANSYS Workbench Meshing.

- Part Manager Names for named selections generated in DesignModeler or other CAD systems that are not written to the .cmdb file by the meshing application.

- Fall Back to Part Manager Names for using named selections generated directly by DesignModeler or other CAD systems as a fall back if no CFX-Mesh, Simulation or Symmetry named selections are found.

Also see Named Selections Involving Interior Faces in the Meshing User's Guide.

##### 9.1.3.1.2. Contact Detection Settings

The Contact check box, when selected, makes contact detection settings available.

When importing ANSYS Mesh files (.cmdb / .dsdb files), it is possible to select Detection Method > Read to read contact information from the file or to select Detection Method > Detect to use the contact detection methods to determine whether regions within the mesh are “in contact” with each other. CFX-Pre uses the Mechanical application contact detection methods to determine which mesh volumes should be placed within each mesh assembly and which 2D regions are connected.

The Read Method setting can be set to `Modify Topology` meaning that CFX-Pre will create connections between pairs of regions according to the contact information read from the ANSYS Meshing file. The topology is modified as part of this process, which can result in two or more bodies becoming part of a single assembly. When using the `Create Regions` option, the contact information read from the file will result in each contact being represented as composite regions on each side of the contact definition allowing easy identification of the contact regions. Using the `Create Regions` option will not modify the underlying topology of the mesh.

The Detection Between setting can be set to Bodies or All Contact. When using the Bodies option, 2D regions will be matched between different bodies. This is the default option and should result in bodies that are “close” to one another being placed in the same mesh assembly. If automatic domain interface generation is selected, interfaces will be generated between such regions. When using the All Contact option, CFX-Pre will still recognize contact between discrete bodies, but in addition, it will look for contact between 2D regions within the same “body”, or “volume”. This can result in unexpected behavior, such as adjacent surfaces being considered “in contact” and hence this is not the default option, but in some cases, where there are non-matched 2D mesh regions within a mesh volume, it can help generate “internal” interfaces.

The tolerance that is used in detecting contact can be altered and it is possible to define it relative to the local geometry size, or as an absolute spatial value.

If CFX-Pre is set to read contact information from the file, then it will import only connections that connect two single regions. Connections connecting multiple regions to a single region, or multiple regions to multiple regions, will be ignored. Also, contact detection works only within a single file; CFX-Pre will not read or detect contact between meshes that are imported from different files.

If the Meshing application is set to generate connections automatically, you can set the Global Contact Setting option to Group By > None to generate only single region to single region connections. For more details, see Generation of Contact Elements in the Meshing User's Guide.

#### 9.1.3.2. CFX-Mesh Files

The CFX-Mesh (.gtm, .cfx) files are native for CFX-Pre; therefore, all information in such a file is read in by the import process. There are no options needed to control the reading of these files.

Note: Only .cfx files that are version 11.0 or newer are supported.

#### 9.1.3.3. CFX-Solver Input files

CFX-Solver files include CFX-Solver input (.def), results (.res), transient results (.trn), and backup (.bak) results files. There are no options specific to importing CFX Def/Res, files but the general advanced options are described in Common Import Options.

For additional information on the regions created in CFX-Pre when CFX-Solver files are imported, see Mesh Topology in CFX-Pre.

#### 9.1.3.4. ICEM CFD Files

ICEM CFD files are of the form .cfx, .cfx5, .msh. There are no import options specific to ICEM CFD files; however the Common Import Options apply.

#### 9.1.3.5. ANSYS Files

ANSYS files are of the form .cdb or .inp. There are no import options specific to ANSYS files; however the Common Import Options apply.

Only .cdb files can be imported into CFX-Pre. If you have an ANSYS .db file, you can convert it to a .cdb file in ANSYS by:

1. Opening the ANSYS database in ANSYS.

2. Issuing the `ALLSEL` command to select everything.

3. Issuing the `CDWRITE, DB` command to write the .cdb file.

To get a list of all element types `(ET)/keyops(KEYOP)` that are supported by mesh import, you can run the following from the operating system command line:

    <CFXROOT>/bin/<OS>/ImportANSYS.exe -S

Note: Before executing the `CDWRITE` command, verify that the data base has a separate named component of 2D MESH200 elements for each surface that will require a boundary condition. Delete any MESH200 elements that are not members of named components. To define specific 3D regions, create a 3D named component of 3D elements. The component names will appear in CFX-Pre as defined regions.

#### 9.1.3.6. Fluent Files

Fluent files of the form .cas and .msh can be imported.

Note: When importing meshes from Fluent files in CFX-Pre, Release 12.0 (or later), the topology and naming of regions may not be the same as those generated by importing these meshes into previous releases. As a result, session files generated in CFX-Pre Release, 11.0 (or earlier) that import meshes from Fluent files may generate errors when loaded into CFX-Pre, Release 12.0 (or later).

##### 9.1.3.6.1. Override Default 2D Mesh Settings

###### 9.1.3.6.1.1. Interpret 2D Mesh as

###### 9.1.3.6.1.1.1. Axisymmetric

This option enables you to create a 3D geometry by extruding a 2D geometry through a specified rotation angle in the third dimension.

Number of Planes:

  This value enables you to create additional planes, arranged in the extruded direction, to create a 3D problem. This will increase the number of elements in the extruded direction, but does not change the enclosed angle of the mesh.

Angle (deg):

  This is the angle through which the original 2D mesh is extruded.

Remove Duplicate Nodes at Axis:

  This check box enables you to choose to have the duplicate node removed from the axis of an axisymmetric case upon import.

###### 9.1.3.6.1.1.2. Planar

This option enables you to create a 3D geometry by linearly extruding a 2D geometry in the third dimension.

Extrude Distance:

  This is the distance through which the geometry is extruded in the third direction.

For further advice on how to model 2D problems in CFX, refer to Modeling 2D Problems in the CFX-Solver Modeling Guide.

#### 9.1.3.7. CGNS Files

CGNS files are of the form: .cgns. Applicable import options are:

- Ignore Invalid Degenerate Elements

- Duplicate Node Checking

##### 9.1.3.7.1. Importing CGNS files into CFX

###### 9.1.3.7.1.1. Method

Mesh data contained within CGNS files can be read into a CFX-Pre after a new case has been created or an existing case has been opened. To read the CGNS file, select the file to import and, if necessary, alter the options used to import the mesh under the Advanced Options section.

Further information on importing files is contained within the standard documentation.

###### 9.1.3.7.1.2. Base (Base_t)

The top-level object in a CGNS file is a container called a base, a CGNS file that can contain multiple bases. What a base contains is user defined so that CFX-Pre allows all bases to be read by one import, or single bases to be read by separate imports.

###### 9.1.3.7.1.3. Zone (Zone_t)

Each base contains one or more zones. For each base read, the import process reads all zones, provided they are 3D dimensional (structured or unstructured zones are supported).

- Grids can be read in single or double precision.

- Zones may be specified in Cartesian or Cylindrical coordinates. Other coordinate systems are not currently supported.

###### 9.1.3.7.1.4. Elements (ElementSection_t)

Element sections can be imported as regions of interest or ignored. How this is done is controlled by the user interface - you must understand which behavior you want to see. It may be useful to import the element sections, for example, if the file has been written with all faces (2D elements) in a boundary patch as a separate element section, which could be useful for setting up the problem in CFX-Pre. Similar scenarios can be imagined in 3D element sections or even mixed element sections.

###### 9.1.3.7.1.5. Element Types Supported

Supported 3D elements (TETRA_4, PYRA_5, PENTA_6 and HEXA_8). Other 3D elements can be read but are reduced to the lower order elements (that is, TETRA_10 is translated to TETRA_4 and then this is imported).

Supported 2D elements (TRI_3 and QUAD_4). Other 2D elements can be read but are reduced to the lower order elements (that is, TRI_6 is translated to TRI_3 and then is imported).

The vertices of 2D elements should ideally be based on the node indices as are used for to define the 3D elements.

It is preferable to define 2D elements with parent information so that mapping from 2D elements to 3D elements does not have to be determined by the process, therefore, reducing import times.

###### 9.1.3.7.1.6. Boundary Conditions (BC_t)

Boundary conditions are processed but physical setup information (for example, equations) is ignored. The facility for importing the CGNS files into CFX (CFX-Pre) is a mesh (grid) importer, not a physics importer.

No physics information is imported. Boundary condition locations are read because the collections (regions) of mesh elements the condition is defined upon are required for ease of use and correct physics setup in CFX.

It is quicker to read boundary conditions when they are defined as a range of elements (`ElementRange`) or a list of elements (`ElementList`), rather than a range of nodes (`PointRange`) or a list of nodes (`PointList`). The latter may also be read, but the nodes referenced must also be used by higher-dimension elements (for example, 3D elements) for correct interpretation.

###### 9.1.3.7.1.7. Families (Family_t, FamilyBC_t, FamilyName_t)

Families are read and, in general, imported as composite regions (groupings) of underlying primitive regions.

###### 9.1.3.7.1.8. Grid Connectivity (GridConnectivity_t and GridConnectivity1to1_t)

Grid connectivity can be read but with certain restrictions.

- If the interface is read from a `GridConnectivity1to1_t` node or is a read from a `GridConnectivity_t node` and is of type `Abutting1to1`, importing of the node mapping is attempted.

- If the node mapping cannot be established or you request that the two sides of the interface are imported as separate regions.

Other interface types are always imported as two separate regions.

###### 9.1.3.7.1.9. CGNS Data Ignored

The CGNS Mid Level Library Documentation Page (http://www.grc.nasa.gov/WWW/cgns/CGNS_docs_current/midlevel/index.html) details the interface used for reading CGNS files within CFX-Pre. The following high level headings used within the document are ignored.

- Simulation Type

- Descriptors

- Physical Data

- Location and Position[3]

- Auxiliary Data

- Solution Data

- Equation specification

- Time Dependent Data

##### 9.1.3.7.2. Prefix regions with zone name

This check box determines whether or not each imported region is prefixed with the name of the zone within which it is defined.

##### 9.1.3.7.3. Create Regions From: Element Sections

Each element section that specifies the topology of elements within the CGNS file may or may not imply a grouping of these elements that is important. If the grouping of elements within each element section is important, this option should be selected so the grouping is preserved within CFX-Pre.

Element sections can be 2D or 3D or a mixture of both, and as such can form 3D regions or 2D regions in CFX-Pre.

The way they are grouped depends on vendor interpretation of the CGNS standard.

##### 9.1.3.7.4. Create Regions From: Boundary Conditions

This check box determines whether or not to import boundary conditions as regions.

##### 9.1.3.7.5. Create Regions From: Families

This check box determines whether or not to import families of elements, or faces as regions.

##### 9.1.3.7.6. Create Regions From: Connectivity Mappings

This check box determines whether or not to import zone interfaces (that is, 1-to-1 and GGI connections) as regions.

##### 9.1.3.7.7. Example of Create Regions From

Consider a CGNS file with one zone, `Zone 1`, made up of four element sections (`ES1` and `ES2` defining the 3D elements, and `ES3` and `ES4` defining the 2D elements). It also contains 2D boundary conditions `BC1` and `BC2`.

These element sections, `ES1` and `ES2`, could consist of, for example, hexahedral elements in `ES1` and tetrahedral elements in `ES2`. In this case, the groupings of elements into the first two element sections appears to be due to their topological identity. However, this may or may not be the case and you must decided as to whether importing these groupings is important.

In this case, it may be that `ES1` and `ES2` should be combined by clearing the Create Regions From: Element Sections option. Another possibility is that `ES1` may be a subregion of mesh that should be kept separate (that is, it will be set up as a subdomain). If that were the case, Element Sections should be selected.

If `BC1` is defined on all the faces in `ES3` and `BC2` is defined on all the faces in `ES4`, then it will probably not be necessary to select Boundary Conditions if Element Sections is selected, as this would introduce complexity in the region definitions (that is, composites would be defined). However if the groupings of `ES3` and `ES4` are different from the groupings in the boundary conditions then Create Regions From: Boundary Conditions should be selected.

##### 9.1.3.7.8. Read Only One CGNS Base

When this toggle is selected, a mesh is read from a single base specified by the CGNS base to read number. If your CGNS file contains only a single base, you should leave the number set to `1`. If it contains more than one base, you should specify the base number from which to read. If the base number specified does not exist, an error will be raised. If it does not contain a valid mesh then a mesh will not be imported.

Note: You must click before you can specify which base to read.

If you disable the Read Only One CGNS Base toggle, then CFX-Pre will look for meshes in all bases and import them. If multiple assemblies are imported and they overlap, then the mesh will be invalid within CFX-Pre unless assemblies are transformed in some way.

For details, see SplitCGNS.exe in the CFX Reference Guide. This is a program that splits a CGNS file into multiple problem files.

#### 9.1.3.8. CFX-TASCflow Files

CFX-TASCflow mesh files are of the form .grd or are simply named `grd`. You may receive warning messages when importing a CFX-TASCflow mesh file: these will usually tell you which regions have not been imported. The sections below indicate the situations when a warning message may occur.

- If Convert 3D Region Labels to Regions is selected, then the 3D Region labels in the .grd file are imported as individual 3D Regions. The default setting omits all 3D Region labels.

- If Ignore One-to-One Connections is selected, then one-to-one contiguous grid connections are deleted on import. You would then have to recreate the connections in CFX-Pre. There are very few cases when you would want to enable this toggle.

- Select the file type for the imported mesh from the GRD File Format Type drop-down. You can select from `Formatted`, `Unformatted` or `Unknown`. If you select `Unknown`, CFX attempts to determine the file format before importing the mesh.

- If Retain Block Off is selected, then “user defined” elements that are blocked off in the mesh file are not imported into CFX-Pre. If not selected, then “user defined” objects are ignored and the elements are included in the imported mesh (rarely desired).

Additional information is available in:

- Ignore Invalid Degenerate Elements

- Duplicate Node Checking.

##### 9.1.3.8.1. Convert 3D Region Labels to Regions

This toggle controls 3D region import from the .grd file only. When selected, 3D regions in the .grd file will be imported into separate 3D primitives in CFX-Pre. If you do not select this option, all mesh elements will be imported into a single 3D primitive that is uniquely named by the import process. 3D regions defined in the .gci and .bcf files are always imported.

##### 9.1.3.8.2. Grid Connections Processed (in the .grd file)

When importing CFX-TASCflow meshes, the only grid connections that are imported automatically are “many-to-one” contiguous topology connections that are specified as one-to-one node pairings.

“Many-to-one” contiguous topology connections that involve any number of many-to-one node groupings are ignored and a warning message is issued; however, the two sides of the connection are preserved as a pair of 2D regions on which a GGI Connection can be defined. You should recreate the connection in CFX-Pre using a Fluid-Fluid Domain Interface. For details, see Creating and Editing a Domain Interface. In some cases, if you have not created regions in CFX-TASCflow on each side of an interface, you will not be able to recreate it in CFX-Pre because there will be no region available for selection. If this occurs, you should explicitly create regions in CFX-TASCflow before importing the mesh into CFX-Pre.

Important: Some ANSYS TurboGrid grids contain many-to-one node groupings. These will not be imported into CFX-Pre. You need to know if your grid contains these connections and then recreate them in CFX-Pre using Fluid-Fluid Domain Interfaces.

“Many-to-one” periodic topology connections are always removed with a warning message issued. You should recreate the connections using a periodic domain interface. For details, see Creating and Editing a Domain Interface.

The regions associated with periodic boundary conditions are imported, but you will need to assign the regions to a periodic domain interface.

##### 9.1.3.8.3. Grid Embedding

Embedded grids, along with the parent grid, are automatically imported into separate assemblies in CFX-Pre. The many-to-one topology connections on the interface between the embedded grid and the parent grid will be removed and a warning issued. You will need to create fluid-fluid domain interfaces between the embedded grid and the parent grid. For details, see Creating and Editing a Domain Interface.

##### 9.1.3.8.4. Retain Block-off

The Retain BlockOff toggle is selected by default. There is no harm in leaving this on, but it is not required unless user defined block-off is defined in the .bcf the file, and you want it to remain blocked-off (ignored).

Porous and CHT objects in the .bcf file are ignored, and must be manually created in CFX-Pre after importing the grid. You should make sure that a 3D volume region was defined in the `grd` file for the porous or CHT object location prior to import.

By default, CFX-Pre will look in the same directory as the `.grd` file to locate the .bcf file. If the .bcf file is located elsewhere, you can browse and select the file.

##### 9.1.3.8.5. Regions in the .grd file

You should delete any regions from the .grd file that are not needed.

If necessary, you can force all “user defined” regions to be included in a .grd file by executing the following command at the TASCtool command prompt:

    TASCtool{}: write grd all_regions_to_grd=on

This is usually not needed because you can import regions from the .gci file directly (see below).

Note that when faces are referenced by more than one named region, the import process will resolve this conflict such that faces are not referenced by more than one region.

##### 9.1.3.8.6. Boundary Conditions in .bcf File

The regions associated with the boundary conditions defined in the .bcf file are imported into CFX-Pre. The boundary condition physics definitions are ignored and must be defined in CFX-Pre.

The CFX-TASCflow symmetry/slip boundary condition should be recreated as either:

- A symmetry boundary condition for flat surfaces.

- A wall boundary condition using the Free Slip option for curved surfaces.

##### 9.1.3.8.7. Regions in the .gci File

Regions in the .gci file defined in (i, j, k) coordinates (such as boundary conditions) are imported if the Use GCI file toggle is selected on the Advanced Options tab. By default, CFX-Pre looks in the same directory as the .grd file for the location of the .gci file. You should select the location of the .gci file by clicking on the browse icon if it is located elsewhere.

Regions defined in physical space (x, y, z coordinates) are always ignored.

An alternative method for reading the .gci file is to force all regions to be included in the .grd file. For details, see Regions in the .grd file.

##### 9.1.3.8.8. Importing CFX-TASCflow TurboPre MFR Grids

You can create multiple domains from a single .grd file if it contains multiple 3D regions or GGI connections. For an MFR grid, a separate assembly will be created for each noncontinuous grid region. This enables a multiple frame of reference (MFR) case to be easily recreated in CFX-Pre from a single mesh import.

Grids from CFX-TASCflow TurboPre usually contain many named regions that may not be required to set up the problem in CFX-Pre. You might want to remove some of these regions before importing the grid to speed up the import of the mesh and simplify the imported mesh.

In CFX-TASCflow TurboPre, you can create multiple copies of blade passages. The ‘open ends’ of the machine section will use a periodic connection. These must be recreated in CFX-Pre using a periodic domain interface. For details, see Creating and Editing a Domain Interface. The internal connection between blade passages can be connected in CFX-TASCflow TurboPre using an automatic periodic boundary condition. If such a connection is used you will have to manually reconnect each passage in CFX-Pre. You might therefore want to define a many-to-one topology connection for one-to-one grid connections so that passages are connected by CFX-TASCflow TurboPre as topology connections (which import immediately). For details, see Grid Connections Processed (in the .grd file).

##### 9.1.3.8.9. Parameter File

CFX-TASCflow does not have units checking, whereas CFX-Pre does. Grid numbers will be imported using the units specified on the Import Mesh dialog box. You should convert all units in the properties and parameter files within TASCflow into SI units (kg, meter, second) prior to import.

#### 9.1.3.9. CFX-4 Grid Files

CFX grid files are of the form .geo.

- Select Split Symmetry Planes to split symmetry planes that exist in more than one region. For details, see Split Symmetry Planes.

- Select Import from Cylindrical Coordinates to transform a problem defined in cylindrical coordinates into Cartesian coordinates for use in CFX-Pre. It should be selected for all CFX-4 problems that use cylindrical coordinates. For details, see Import from Cylindrical Coordinates.

- Select Block Interfaces to create 2D regions in CFX-Pre on block interfaces. For details, see Create 2D Regions on.

- Import 2D axisymmetric mesh. For details, see Import 2D Axisymmetric Mesh.

Other available options are:

- Ignore Invalid Degenerate Elements

- Duplicate Node Checking

##### 9.1.3.9.1. Split Symmetry Planes

The Split Symmetry Planes option is on by default. Symmetry planes that are defined by more than one CFX-4 region will be split so that each definition is imported. For example, a symmetry plane that is defined on two sides of a 3D region will be split into regions named `<regionname>1` and `<regionname>2,` and so on, where `<regionname>` is the original name of the symmetry plane in the CFX-4 file.

##### 9.1.3.9.2. Import from Cylindrical Coordinates

CFX-Pre can import problems defined in Cylindrical Coordinate (x, r, ) form from CFX-4. The problem is converted to Cartesian Coordinates (x, y, z) by the import process. The resulting CFX-Solver input file will not be written in cylindrical coordinates. You must select the Import from Cylindrical Coordinates option to successfully import a CFX-4 cylindrical coordinate problem.

Note: This is not the same as an axisymmetric problem. For details, see Import 2D Axisymmetric Mesh.

##### 9.1.3.9.3. Create 2D Regions on

Block Interfaces

  When this option is selected, named regions will be created on the interfaces between mesh blocks. This can produce many regions in CFX-Pre, so it is usually better to define all the regions you require as patches in CFX-4.

##### 9.1.3.9.4. Create 3D Regions on

Fluid Regions (USER3D, POROUS)

  In CFX-4, most 3D regions are classified as USER3D patches. Porous regions are treated in the same way as USER3D regions when importing them into CFX-Pre. When the Fluid Regions (USER3D, POROUS) toggle is not selected, these regions are not imported. When the toggle is selected, they are imported as separate 3D regions. This toggle should be selected if you need the USER3D regions to create domains and subdomains. You should disable it to simplify the regions created in CFX-Pre. If, in CFX-4, you have created a USER3D region for the purpose of creating thin surfaces, you do not need to import the USER3D region in CFX-Pre because thin surfaces can be defined without the need for a separate subdomain.

##### 9.1.3.9.5. Blocked Off Regions (SOLIDs)

- If Fluid Regions (USER3D, POROUS) is not selected, and Blocked Off Regions (SOLIDs) is not selected, then SOLID regions are blocked-off (that is, this part of the mesh is not imported).

- If Fluid Regions (USER3D, POROUS) is not selected, and Blocked Off Regions (SOLIDs) is selected, then SOLID regions are imported into the default 3D region created by the import process.

- If Fluid Regions (USER3D, POROUS) is selected, and Import SOLID regions is toggled OFF, then SOLID regions become blocked-off (that is, this part of the mesh is not imported).

- If Fluid Regions (USER3D, POROUS) is selected, and Import SOLID regions is toggled ON, then SOLID regions are imported as separate 3D regions (which can be useful for CHT simulations).

##### 9.1.3.9.6. Conducting Solid Regions (SOLCONs)

- These are regions defined as conducting solid regions in CFX-4. There is no way to completely ignore SOLCON regions, they are always imported as either a separate region or as part of the parent region. If you want to ignore these regions (that is, so that there is no flow), then they should be removed from the CFX-4 mesh file using CFX-4 or with manual editing. Alternatively they can be imported but simply not used to define a subdomain in CFX-Pre. The import behavior is described below:

  - If Fluid Regions (USER3D, POROUS) is not selected, and Conducting Solid Regions (SOLCONs) is not selected, then SOLCON regions are imported as part of the “Assembly 3D” region.

  - If Fluid Regions (USER3D, POROUS) is not selected, and Conducting Solid Regions (SOLCONs) is selected, then SOLCON regions are imported as separate 3D regions.

  - If Fluid Regions (USER3D, POROUS) is selected, and Conducting Solid Regions (SOLCONs) is not selected, then SOLCON regions are imported as part of the regions in which they appear.

  - If Fluid Regions (USER3D, POROUS) is selected, and Conducting Solid Regions (SOLCONs) is selected, then SOLCON regions are imported as separate 3D regions and will be cut out of the parent regions.

##### 9.1.3.9.7. Import 2D Axisymmetric Mesh

You can enable this toggle if you want to import a mesh created as a 2D mesh on an axisymmetric section in CFX-4. This is different to a mesh defined using cylindrical coordinates; however, it can also use an (x, r, ) coordinate system. The CFX-4 mesh must be only 1 element thick in the k direction to use this option.

The Number of Planes value enables you to create additional planes in the direction within the original 2D mesh to create a 3D problem. This will increase the number of elements in the k direction, but does not change the extent of the mesh.

The Angle value should be the angle of the mesh section in degrees. Because the mesh is only one element thick, then is the same for all nodes.

##### 9.1.3.9.8. Importing MFR Grids

If you have a CFX-4 MFR case, it can easily be imported into CFX-Pre and recreated.

- Each noncontinuous mesh section will be imported into a separate assembly.

- Each USER3D region will be imported into a separate 3D primitive.

- Both assemblies and 3D primitives can be used to create separate domains.

#### 9.1.3.10. CFX-BladeGenPlus Files

CFX-BladeGenPlus files are of the form .bg+. There are no options specific to importing CFX-BladeGenPlus files. For details, see Common Import Options.

#### 9.1.3.11. PATRAN Neutral Files

PATRAN Neutral files are of the form .out.

- Select Import Distributed Loads as 2D Regions to convert predefined distributed loads as 2D primitives within CFX-Pre.

For details, see Common Import Options.

#### 9.1.3.12. IDEAS Universal Files

IDEAS Universal files are of the form .unv.

- Select the entities, under IDEAS Universal Specific Options, to import from Permanent Groups.

For details, see Common Import Options.

IDEAS mesh files contain groups of nodes, faces and/or elements. The groups can be normal groups or permanent groups. The normal groups are imported into CFX-Pre as up to three separate regions, depending on the information available in the mesh file. These regions will be named:

- `<groupName>_Nodes`

- `<groupName>_Faces`

- `<groupName>_Elements`

Only permanent groups of the selected types are imported into CFX-Pre. If overlapping regions are imported, CFX-Pre will split them into distinct regions; therefore, you may not want to import all permanent group types.

#### 9.1.3.13. GridPro/az3000 Grid Files

GridPro/az3000 ‘grid’ files are of the form .grid.

- Select Include Periodic Regions to convert predefined periodic boundaries into 2D primitives on import.

- Select Ignore Connectivity to import grid blocks as unconnected 3D primitives. Ignoring connectivity does not equivalence nodes at grid block interfaces.

- Select Import Grid Blocks as Subdomains so that for each predefined grid block, a separate 3D primitive is created.

- Selecting Ignore Properties causes data in the properties file to be ignored. This includes boundary conditions, 2D and 3D regions, and other data.

Additional information is available in:

- Ignore Invalid Degenerate Elements

- Duplicate Node Checking.

#### 9.1.3.14. NASTRAN Files

NASTRAN files can be imported.

- When Include Subdomains is cleared, all mesh elements are merged into a single 3D primitive.

- “Distributed loads” are pressure boundaries that, if imported, are used to generate 2D primitives in CFX-Pre. Select Import Loads as 2D Regions to import distributed loads.

Additional information is available in:

- Ignore Invalid Degenerate Elements

- Duplicate Node Checking.

#### 9.1.3.15. Pointwise Gridgen Files

Pointwise Gridgen files can be imported. There are no options available specific to the Pointwise Gridgen format. For details, see Common Import Options.

#### 9.1.3.16. User Import

If you should require facilities for importing a mesh other than those available through the standard Mesh Import forms, you can create your own customized mesh import program and make it available through the Import Mesh forms. For details, see Volume Mesh Import API in the CFX Reference Guide. If you have created your own mesh import program, it must be run from within CFX-Pre; one way of doing this is by using the Import Mesh dialog box.

To run a custom import program using the Import Mesh dialog box:

1. Open the Import Mesh dialog box.

   For details, see Importing Meshes.

2. Set Files of Type to `User Import(*)`.

3. Select the file containing the mesh to import.

4. Click Browse to browse to the location of the user executable file or enter its name under Exec Location.

5. Under Exec Arguments, enter the command-line arguments that should be passed to the import program.

6. Set advanced options as required.

   For details, see:

   - Ignore Invalid Degenerate Elements

   - Duplicate Node Checking

7. Click Open.

CFX-Pre calls the custom import program with a command line that has the following form:

`<user import executable> <executable arguments> <mesh file>`

It is important therefore that the executable handles any arguments that are specified.

If you usually use a particular import program, you can set it as the default import program by any one of the following methods:

- Specify the full pathname of the import program, and other settings, in the Options dialog box.

- Add the following line to the .cfx5rc file:

  `CFX_IMPORT_EXEC="<`executable_path`>"`

  where `<`executable_path`>` is the full path and name of your executable.

  For details, see Resources Set in cfx5rc Files in the CFX Introduction.

- Set `CFX_IMPORT_EXEC` in the system environment.

[3] Rind Data is processed but not imported.

Release 18.2 - © ANSYS, Inc. All rights reserved.