cfx import cgns

CFX-Build: Chapter 2 RetraceMasterContents

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CFX-Build: Chapter 2

Importing Meshes intoCFX-Build

• Introduction to the Import Mesh Form p. 942

• Create / Mesh Group p. 946

• Delete / Mesh Group p. 967

• Transform / Mesh p. 968

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CFX-Build: Chapter 2Importing Mesh Groups

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Introduction to the Import Mesh Form

CFX-5 has been developed to allow you easy access to models thathave already been created. Existing meshes generated with otheranalysis packages or CFX products can be imported into a MeshGroup in CFX-Build. Domains, which each contain a Mesh Group , arethen joined together via Domain Interfaces and used with the CFX-5Solver.

Predefined boundary condition locations, Sub-domains, and theirassociated labels are also imported. CFX-5 type Boundary Conditionsand sources may then be applied to these objects.

The Import Mesh form is only available when you select the ImportMesh mode on the New Model Preferences Form (p. 20 inCFX-Build Basic Functions) which appears when you create a newCFX-Build database. The database will then be set up for Import Meshmode every time you open the database.

You can select from a range of different import sources, performchecks on the integrity of the imported mesh, and maintain, merge orignore predefined model regions within the imported mesh file.

The following points should be noted about imported meshes:

• The number and location of Boundaries (2D regions) andSub-domains (3D regions) is defined by the software whichgenerated the mesh. Although you can apply any CFX-BuildBoundary Condition to an imported 2D region, and create Sub-domains on any imported 3D region, you cannot create new regionsor change the location of existing regions. The imported mesh willalso require distinct 2D regions to form domain interfaces with otherimported meshes. In this respect, domain interfaces can be thoughtof as Interface Boundary Conditions.

• You cannot change to any other mesh mode for the database onceyou have selected the Import Mesh mode.

• You can import more than one mesh per CFX-Build model andconnect them together via a Domain Interface, see DomainInterfaces (p. 1169 in CFX-Build: Chapter 7) .

• You cannot recreate an imported mesh or change the elementtype(s).

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• When you re-open a database that contains imported meshes, youwill receive a message asking you if you want to re-import themeshes.

• If you select Yes the meshes are automatically re-imported anddisplayed in the Viewport. This can take some time if yourimported meshes are large.

• If you select No you will not be able to import any additionalmeshes during the CFX-Build session. You can change thevalues applied to existing Domains, Sub-domains and BoundaryConditions, but you cannot create any new regions or change thelocation of existing regions.

• The name and location of the mesh file is stored in the CFX-Builddatabase and used as a reference to locate and import the mesheach time the database is opened. This helps to minimise file sizes,by not storing the nodes and elements of an imported mesh in thedatabase. For this reason you should not change the location orname of an imported mesh if you want it to be automatically re-imported. If the location or name of the mesh file is changed, orCFX-Build cannot find the mesh (this will happen when switching adatabase from Windows to UNIX platforms, or vice versa, due to filepath differences), then an import error message will appear:

Click on each message to openthe form below showing moredetails. You will need to re-importeach mesh for which there is anerror message.

Click to re-import the mesh. This opens a file selection form whereyou can select the new location for the imported mesh.




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Once you have relocated a mesh file, you will not need to locate itagain in subsequent CFX-Build sessions.

Note that when the file selection form appears, you will not be ableto change the Source type of the mesh. This route for re-importingmeshes is designed only to allow you to re-import the same meshwhen its location has changed or when switching betweenplatforms.

• You can import the following formats of mesh files:

• ANSYS (p. 950)• CFX-4 (p. 951)• CFX-5 Def/Res file (p. 954)• CFX-TASCflow v2 (p. 956)• CGNS (p. 961)• ICEM CFD (p. 962)• IDEAS Universal (p. 962)• PATRAN Neutral (p. 963)• User Import (p. 963)• CFX-TfC 1.3 (p. 964)• CFX-5.1 (p. 965)• GridPro/az3000 (p. 965)• MSC/NASTRAN (p. 966)• Pointwise Gridgen (p. 966)

When running in the Import Mesh mode, you will also notice that theMesh button is not available from the main toolbar since the meshalready exists. Geometry is not available since no new geometry canbe created. New 2D and 3D Regions cannot be created so thesebuttons are also unavailable.

The file selection form is used to create Mesh Groups by importing amesh from an existing file. The file containing the mesh can beproduced using CFX-5, other CFX products, a CAD package or othermesh generation software.

Once imported into CFX-Build, the Mesh Groups can be manipulatedusing transformation tools to position each mesh as required.




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After a Domain is created for each Mesh Group (see Introduction toFluid Domains (p. 1023 in CFX-Build: Chapter 4) ), the Mesh Groupsare joined together using the General Grid Interface (GGI) capability ofCFX-5 (see Domain Interfaces (p. 1169 in CFX-Build: Chapter 7) ).




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Create / Mesh Group

The Create / Mesh Group form is used to define the name of a MeshGroup and select the mesh to import into that group. You must definea new Mesh Group for each mesh you wish to import. Only one meshcan be imported per Mesh Group.

Enter a name for the Mesh Group

After specifying the file containing the mesh to beimported, click Apply to import the mesh.

Select the format of the mesh file that youwish to import.

Existing Mesh Groups are displayed here.

Click to open the Advanced Options form. This form isused to set properties for the type of mesh that you areimporting..

Click to open a file browser which allows you tolocate the mesh file you wish to import.

Select from:

• ANSYS• CFX-4• CFX-5 Def/Res file• CFX-TASCflow v2• CGNS• ICEM CFD• IDEAS Universal

• PATRAN Neutral• User Import• CFX-TfC 1.3• CFX-5.1• GridPro/az3000• MSC/Nastran• Pointwise Gridgen

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Mesh Import FileThis form is used to browse to the mesh file that you wish to load. Theappearance of this form differs to that shown on UNIX platforms.

Browse to the mesh file.

The file type thatCFX-Build filters changesaccording to the meshSource type.




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Advanced Options

General Advanced Options

On the Import Mesh form you should select the Source format for theimported mesh from the drop-down list. Various Advanced Options arethen available for each Source type. The options shown on the formbelow are generic to all Source types (except User Import). The optionsspecific to each Source type are described on the following pages.

Create 2D regions on internal 3D regions

You can enable this toggle on the Import Mesh form to importpredefined boundaries which are attached to 3D regions. This allowsyou to specify, for example, thin surfaces on 2D regions definedoutside of CFX-Build. If you wish to import thin surfaces you shouldtherefore make sure that they are defined as boundaries of internal 3Dregions. For example, in CFX-4, thin surfaces should be boundaries ofUSER3D patches.

Additional options are available for most Source types.Follow the links for the relevant Source . Select from:

See Split Overlapping 3DRegions (p. 949) , Create 2Dregions on internal 3D regions(p. 948) and Ensure CorrectElement Orientation (p. 949)

See Duplicate Node Check(p. 949)

• ANSYS• CFX-4• CFX-5 Def/Res file• CFX-TASCflow v2• CGNS• ICEM CFD• IDEAS Universal

• PATRAN Neutral• User Import• CFX-TfC 1.3• CFX-5.1• GridPro/az3000• MSC/Nastran• Pointwise Gridgen




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This function is not available for databases created in CFX-5.3 orCFX-5.4, so is only available when creating new Import Meshdatabases in CFX-5.5.1 and for databases created in CFX-5.4.1.

Split Overlapping 3D Regions

This toggle turns on a check that compares every 3D region with everyother 3D region to see if they overlap. When the toggle is turned on andoverlapping regions are found, they are split into distinct regions. Forexample, if regions A and B partially overlap then three regions will beimported:

• Imported region A will contain mesh elements found only in meshregion A.

• Imported region B will contain mesh elements found only in meshregion B.

• An additional region will be created containing mesh elementsfound in both regions A and B.

When this toggle is OFF the check is not performed. Elementsoriginally in more than one 3D region will be imported into more thanone region, this can cause the CFX-5 Solver to fail.

This toggle is OFF by default since it can be a time consuming process.It should be turned ON if mesh elements appear in more than one 3Dregion.

Ensure Correct Element Orientation

This checks elements as they are imported for negative volumes.CFX-5 requires that all elements are of the same orientation (i.e. rightor left handed) and will convert those with negative volumes on import.If this toggle is not enabled you may receive error messages in theCFX-5 Solver about negative volumes.

Duplicate Node Check

The Duplicate Node Check equivalences nodes within the specifiedTolerance. This should be enabled when importing meshes with thinsurfaces from CFX-5 Def/Res files. Also see Duplicate NodeChecking (p. 956) for importing CFX-TASCflow grid files.

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Importing Predefined Boundaries

Predefined boundary locations can be imported into CFX-Build andused to define CFX-5 type Boundary Conditions. The boundaries aredefined by the set of mesh element faces on that boundary. Theoriginal boundary condition types and values are not imported.

CFX-Build will also read in any label associated with an importedboundary location. Any external mesh element faces which are not partof any predefined boundary are automatically grouped into a CFX-5Boundary named ‘UNLABELED_BOUNDARY’.

Any overlapping 2D regions are always split into distinct regions uponimport.

Applying CFX-5 Boundary Conditions

You can apply any valid CFX-5 Boundary Condition to any importedBoundary. When you open the Boundary Conditions forms, CFX-Buildautomatically displays the imported boundaries for selection.

Boundaries which remain unspecified, default to the No Slip(Stationary) Adiabatic Wall type when the Definition File is written.

Viewing the Imported Mesh

You can view the imported mesh at any Boundary location using theDisplay > Imported Mesh forms. For more information see ImportedMesh (p. 228 in CFX-Build Basic Functions) .

ANSYS

Import a mesh from an ANSYS file (*.cdb ). There are not any optionsspecific to the ANSYS format. See General Advanced Options(p. 948) for details on the generic options available on this form.

Only cdb files can be imported into CFX-Build. If you have an ANSYSdb file you can convert it to a cdb file in ANSYS using the followingmethod:

• Open the ANSYS database in ANSYS.

• Issue the ALLSEL command to select everything.

Issue the CDWRITE,COMB command to write the cdb file.




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CFX-4

Import a mesh from a CFX-4 grid file (*.geo).

For help on this section of the form, refer to Create 3DRegions on: (p. 952)

• This toggle should be ON when you wish to importUSER3D/Porous region types for setting upSubdomains and sources. On by default. See below formore details.

• Import SOLID regions: Off by default.• Import mesh elements generated as conducting solid

regions. These regions can be imported for specifyingsolid sub-domains in CFX-5. On by default.

Import a 2D Axisymmetric mesh. See 2D Mesh Options:(p. 954).

This section of the form is generic for all Sources. TheCreate 2D regions on internal 3D regions can be usedfor importing thin surfaces. These should be boundariesof USER3D patches. See General Advanced Options(p. 948) for details on this section.

This toggle will split symmetry planes which exist in morethan one region. See Split Symmetry planes (p. 952) .

If you wish to use block interfaces to create boundaries inCFX-5, then this toggle should be selected (off by default).See Create 2D Regions on: (p. 952) for further help

This toggle will transform a problem defined in cylindricalcoordinates into cartesian coordinates for use in CFX-5. Itshould be enabled for all CFX-4 problems that usecylindrical coordinates. See Import from CylindricalCoordinates (p. 952)




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Split Symmetry planes

Symmetry planes which exist in more than one CFX-4 region will besplit (for example, a symmetry plane which is defined on two sides of a3D region will be split into regions named <regionname>1 and<regionname>2, etc., where <regionname> is the originalsymmetry plane name in the CFX-4 file).

Import from Cylindrical Coordinates

CFX-5 allows import of Cylindrical Coordinate problems (x, r, θ) fromCFX-4. The problem is converted to Cartesian Coordinates (x, y, z) inCFX-5. The resulting CFX-5 definition file will not be written incylindrical coordinates. You must enable the Import from CylindricalCoordinates toggle to successfully import a CFX-4 cylindricalcoordinate problem. This is NOT the same as an axisymmetricproblem, see 2D Mesh Options: (p. 954) for details on import ofaxisymmetric grids.

Create 2D Regions on:

• Block Interfaces - When this toggle is enabled, named regions willbe created on the interfaces between mesh blocks. This canproduce many regions in CFX-5, so it is usually better to define allthe regions you require as patches in CFX-4. When this toggle isenabled, you may also overwrite patches that were defined inCFX-4 if a block interface coincides with the patch. This preventsduplicate regions, but you will see a different name for the region tothat which was defined in CFX-4.

Create 3D Regions on:

• Fluid Regions (USER3D, POROUS) - In CFX-4 most 3D regionsare called USER3D regions. Porous regions are treated in the sameway as USER3D regions when importing them into CFX-5. Whenthe Fluid Regions (USER3D, POROUS) toggle is OFF, theseregions are grouped into a CFX-5 Sub-domain namedUNLABELED_SUBDOMAIN. When the toggle is ON, they areimported as separate 3D regions. If you are importing thin surfacesfrom CFX-4, you should make sure that they are defined in CFX-4as boundaries of USER3D patches.

• Blocked Off Regions (SOLIDs) - In CFX-4, SOLID regions have noflow and hence no mesh.




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• If Fluid Regions (USER3D, POROUS) is toggled OFF, andBlocked Off Regions (SOLIDs) is toggled OFF, then SOLIDregions become blocked-off (i.e. this part of the mesh is notimported).

• If Fluid Regions (USER3D, POROUS) is toggled OFF, andBlocked Off Regions (SOLIDs) is toggled ON, then SOLIDregions are imported into the UNLABELED SUBDOMAIN region(not as separate 3D regions).

• If Fluid Regions (USER3D, POROUS) is toggled ON, andImport SOLID regions is toggled OFF, then SOLID regionsbecome blocked-off (i.e. this part of the mesh is not imported).

• If Fluid Regions (USER3D, POROUS) is toggled ON, andImport SOLID regions is toggled ON, then SOLID regions areimported as separate 3D regions (which can be useful for CHTapplications).

• Conducting Solid Regions (SOLCONs) - These are regionsdefined as conducting solid regions in CFX-4. There is no way tocompletely ignore SOLCON regions, they are always imported aseither a separate region or as part of the parent region. If you wishto ignore these regions (i.e. so there is no flow), then they should bedefined as SOLID regions in CFX-4. The import behaviour isdescribed below:

• If Fluid Regions (USER3D, POROUS) is toggled OFF, andConducting Solid Regions (SOLCONs) is toggled OFF, thenSOLCON regions are imported as part of the UNLABELEDSUBDOMAIN.

• If Fluid Regions (USER3D, POROUS) is toggled OFF, andConducting Solid Regions (SOLCONs) is toggled ON, thenSOLCON regions are imported as separate 3D regions.

• If Fluid Regions (USER3D, POROUS) is toggled ON, andConducting Solid Regions (SOLCONs) is toggled OFF, thenSOLCON regions are imported as part of the regions in whichthey appear.

• If Fluid Regions (USER3D, POROUS) is toggled ON, andConducting Solid Regions (SOLCONs) is toggled ON, thenSOLCON regions are imported as separate 3D regions and willbe cut out of the parent regions.




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2D Mesh Options:

Import 2D Mesh as Axisymmetric Mesh - You can enable this toggleif you wish to import a mesh created as a 2D mesh on an axisymmetricsection in CFX-4. This is different to a mesh defined using cylindricalcoordinates, however it can also use an (x, r, θ) coordinate system.The CFX-4 grid must be only 1 element thick in the k direction to usethis option.

By default the original points and angle of the section are used. Sincethe mesh is only one element thick, then θ is same for all nodes. Youcan override the value of θ used in CFX-4 by enabling the SpecifyAngle toggle and entering an angle.

The Specify number of planes in theta toggle allows you to createadditional planes within the original 2D mesh to create a 3D problem.This will increase the number of elements in the k direction, but doesnot change the extent of the mesh.

Importing MFR Grids

In CFX-5, each imported mesh must form one domain in a single frameof reference. If you have a CFX-4 MFR case, you will need to import aseparate mesh for each unique frame of reference.

CFX-5 Def/Res file

Import a mesh from a CFX-5 Definition (*.def) or Results (*.res) file.There are no options available specific to importing CFX-5 Def/Resfiles. See below and General Advanced Options (p. 948) for adescription of the general options available on this form.

If the mesh in your definition or results file includes thin surfaces, thenyou should always enable the Duplicate Node Check toggle.

The Split Overlapping 3D Regions toggle does not affect importsfrom a CFX-5 Def / Res file since you cannot create overlappingregions in CFX-5. This toggle should therefore always be turned OFFto make importing quicker.

The Check Elements toggle is not needed for imports from a CFX-5Def / Res file and should also always be disabled.




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If the Definition or Results file to be imported contains more than onefluid domain, then all domains are imported into a single fluid domain,with each original fluid domain becoming a sub-domain in the importedmesh. For this reason, you will not be able to re-create a multiple frameof reference (MFR) simulation by imported a single MFR Definition orResults file. The Create 2D regions on internal 3D regions toggledoes not affect importing of the interface boundaries between the sub-domains which are created in such cases. Using duplicate nodechecking will not affect the mesh at the interface.

When importing a Def / Res file that contains a Solid sub-domain youcan leave Create 2D regions on internal 3D regions ON. This willimport the solid side and fluid side boundaries using the labels definedin the Def / Res file. If you disable this toggle, the solid side and fluidside boundaries will still be correctly imported, but they will be assignednew labels (e.g. B1, B2). In general, the Create 2D regions oninternal 3D regions toggle will not affect a mesh imported from a Def/ Res file, only the naming of boundaries.




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CFX-TASCflow v2

Import a mesh from a CFX-TASCflow v2 grid file (*.grd).

Duplicate Node Checking

This equivalences nodes within the specified tolerance into a singlenode (duplicate node removal). When importing CFX-TASCflow grids,you should only enable the Duplicate Node Check (the default is ON)in the following situations:

• to import CHT solid/fluid interfaces correctly. This is so that the pairsof boundary faces on the fluid and CHT solid side of a fluid/solidone-to-one interface are treated correctly. If the Duplicate NodeCheck toggle is not selected, two unconnected boundary faces willbe created (one exposed to the fluid, one exposed to the solid)which do not permit fluid/CHT solid heat transfer to occur.

If ON then “user defined” BlockOff objects are treatedas blocked-off (deleted) during the import of themesh. If OFF, “user defined” objects are ignored andthe elements are included in the imported mesh(rarely desired).

If ON then the 3D Region labels in the grd file areimported as individual 3D Regions. The defaultsetting omits all 3D Region labels.

Select the file type for the imported mesh. You canselect from Formatted, Unformatted or Unknown. Ifyou select Unknown, CFX-5 attempts to determinethe file format before importing the mesh.

This section of the form is generic for all Sources.See Mesh Import File (p. 947) for details on thissection.

Important additional details for importingCFX-TASCflow grids relevant to this section of theform are given below.

If ON then one-to-one contiguous grid connectionsare deleted on import. You would then have to re-create the connections in CFX-5. There are very fewcases when you would want to enable this toggle.




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• to import pinch grid regions correctly. In this case multiple nodes atthe same location are collapsed into a single node (with a wedgetype element). This is a much more robust situation than thetraditional “symmetry/slip” condition used at pinched grid regions forCFX-TASCflow simulations.

The Duplicate Node Check Is very CPU expensive, and should not beused unless one of the above features exist in your problem setup. Bydefault this toggle is OFF. There is no harm to have it ON when it is notneeded, except wasted CPU time.

When the Duplicate Node Check has been used, you should manuallycheck that the correct coincident nodes where detected and merged.The correct Tolerance must be set for the Duplicate Node Check forthis function to work correctly. If the tolerance is too small, somecoincident nodes may not be detected and remain as distinct nodes. Ifthe tolerance is too large, some nodes that are close, but not actuallycoincident, may be deemed to be coincident and erroneously collapsedinto one node.

The correct tolerance should be much smaller than the smallestphysical spacing between two non-coincident nodes.

Convert 3D Region Labels to Regions

For volume meshes which have predefined Sub-domains(3D Regions) you can select to keep their definition, or mergeSub-domain elements into a single Fluid Domain. Unlabelled 3Dregions are automatically grouped into a CFX-5 Sub-domain named‘UNLABELED_SUBDOMAIN’.

Grid Connections Processed (in the grd file)

When importing CFX-TASCflow grids, the only grid connections thatare correctly imported automatically are “many-to-one” contiguoustopology connections that involve only one-to-one node pairings.These must be defined in the grd file.




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“Many-to-one” contiguous topology connections that involve anynumber of many-to-one node groupings are silently deleted. You willneed to locate these regions in CFX-Build and connect then using aFluid-Fluid GGI Interface, see Fluid-Fluid Interfaces (p. 1173 inCFX-Build: Chapter 7) .

“Many-to-one” periodic topology connections are always silentlydeleted. If the periodic connection involved many-to-one nodegroupings, you will need to create a Periodic GGI Interface inCFX-Build, see Periodic Interfaces (p. 1174 in CFX-Build:Chapter 7) . If the periodic connection was a one-to-one gridconnection you can create either a Periodic GGI Interface or a PeriodicBoundary Condition (recommended), see Periodic Pair (p. 1130 inCFX-Build: Chapter 6) .

Periodic Boundary Conditions are not imported. You should re-createthese using a Periodic Pair Boundary Condition in CFX-Build.

Regions in the grd file

Regions are imported only from the grd file. Regions of single nodes,1D lines and 3D groups of elements are deleted by default. 2D regionsare always imported. You can import 3D regions by enabling theConvert 3D Region Labels to Regions toggle.

We recommend that you delete any regions from the grd file that arenot needed. You should also make sure that all required regions areincluded in the grd file. Regions defined in the gci file are NOTimported .

If necessary, you can force all “user defined” regions to be included ingrd file by executing the following command at the TASCtoolcommand prompt:

TASCtool{}: write grd all_regions_to_grd=on

Finally, note that when faces are references by more than one namedregion, the import process will resolve this conflict such that no facesare referenced by more than one region name.

Important: Some CFX-TurboGrid grids contain some many-to-onenode groupings in just a few places. These will not be imported intoCFX-Build. You need to know if your grid contains these connectionsand then re-create them in CFX-Build using Fluid-Fluid GGIInterfaces.




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Grid Embedding

Embedded grids, along with the parent grid, are automatically importedinto CFX-Build. The many-to-one topology connections on theinterface between the embedded grid and the parent grid will bedeleted automatically and silently. You will need to create Fluid-FluidGGI Interfaces between the embedded grid and the parent grid, seeFluid-Fluid Interfaces (p. 1173 in CFX-Build: Chapter 7) .

Block-off in bcf File

The Retain BlockOff toggle is enabled by default. There is no harm inleaving this ON, but it is not required unless user defined block-off isdefined in the bcf the file, and you wish to it to remain blocked-off(deleted).

Porous and CHT objects in the bcf file are ignored, and must bemanually created in CFX-5 after importing the grid. You should makesure that a 3D volume region was defined in the grd file for the porousor CHT object location prior to import. You will also need to turn theImport 3D Regions toggle ON so that the 3D region is imported.

For CHT objects it is also critical that the Duplicate Node Checktoggle is ON, see Duplicate Node Check (p. 949) .

Boundary Conditions in bcf File

These are totally ignored and must be manually re-created in CFX-5.

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

• A Symmetry Boundary Condition for flat surfaces.

• A Wall Boundary Condition using the Free Slip option for curvedsurfaces.

Importing TurboPre MFR Grids

Each grid imported into CFX-5 is used to form a single domain. Youcannot import multiple grd files into a single domain or create multipledomains from a single grd file.

You can use TurboPre to create 360 components or set up complexMFR cases, then use a “block-off trick” to create separate domains inCFX-5 from one grd file. To do this:




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• In CFX-TASCflow, block-off all rotating frame elements with a single“User Block-off” object. Write the bcf file.

• Import this grd and bcf file combination into CFX-5 to define thestationary frame domain.

• Go back to CFX-TASCflow. Delete the rotating domain block-offobject, then create a single “User Block-off” object that blocks-off allof the stationary frame elements. Write a bcf file.

• Import this grd and bcf file combination into CFX-5 to define therotating frame domain.

• Repeat this two step process for each unique frame of reference(usually there are only two unique frames of reference).

The regions do not have to be contiguous, for example, for a stator/rotor/stator geometry, the two stator regions can be included in a singlegrd and bcf file and a single domain in CFX-5.

TurboPre grids usually contain many named regions that are notrequired in CFX-5. You also might want to remove some of theseregions before importing the grid to simplify the imported grid.

In TurboPre you can create multiple copies of blade passages. The‘open ends’ of the machine section will use a periodic connection,these must be re-created in CFX-Build as described in GridConnections Processed (in the grd file) (p. 957) . The ‘internal’connection between blade passages can be connected in TurboPreusing an ‘automatic periodic boundary condition’. If such a connectionis used you will have to manually re-connect each passage inCFX-Build. You might therefore want to define a “many-to-one”topology connection for one-to-one grid connections so that passagesare connected by TurboPre as topology connections (which importimmediately). See Grid Connections Processed (in the grd file)(p. 957) for more details.

Important: TurboPre problem setups contain regions that are notdefined in the grd file. You should add all regions to the grd filebefore importing as described in Regions in the grd file (p. 958) .




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Parameter File

CFX-TASCflow does not have units checking whereas CFX-5 does.By default, grid numbers will be imported and assumed to be in metres.We recommend that you convert all units in the properties andparameter files into SI units (kg, meter, second).

CGNS

Import a mesh from a CGNS file (*.cgns). There are not any optionsavailable specific to the CGNS format. See General AdvancedOptions (p. 948) for details on the generic option available on thisform.

CGNS base to read

When the Read only one CGNS base toggle is enabled, a mesh isread from a single base specified by the CGNS base to read number .If your CGNS file only contains a single base, you should leave thenumber set to 1. If it contains more than one base you should specifythe base number from which to read. If the base number specified doesnot exist an error will be raised. If it does not contain a valid mesh thena mesh will not be imported.

This section of the form is generic for allSources. See General Advanced Options(p. 948) for details on this section.

This toggle is disabled by default. If yourCGNS file contains more than one base, youcan enable this toggle and specify the basenumber which the mesh is imported from. Seebelow for more details.




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If you disable the Read only one CGNS base toggle, then CFX-5 willlook for meshes in all bases and import them. If multiple meshes areimported and they overlap, then the mesh will be invalid.

ICEM CFD

Import a mesh from an ICEM CFD file. There are not any optionsavailable specific to the ICEM CFD format. See General AdvancedOptions (p. 948) for details on the generic option available on thisform.

IDEAS Universal

Import a mesh from an IDEAS Universal file.

This section of the form is generic for all Sources. SeeGeneral Advanced Options (p. 948) for details onthis section.

By default, the IDEAS reader reads the elements of adata set and ignores the nodes. If you wish to readnodes instead of elements, you can enable this toggle.




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PATRAN Neutral

Import a mesh from a PATRAN Neutral file (*.out).

User Import

If you should require facilities for importing a mesh other than thoseavailable through the standard Import Mesh forms, you can create yourown customised mesh import program and make it available throughthe Import Mesh forms.

For information on how to do this see Customising Import Mesh(p. 973).

Convert predefined Distributed Loads 2D Regions intoCFX-5 Fluid Boundaries on import.





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If you have created your own mesh import program you can access itthrough the Import Mesh form.

CFX-TfC 1.3

Import a mesh from a CFX-TfC 1.3 grid file (*.gem).

Enter the arguments for the User Executable.

Enter the User Executable file name.

These toggles are discussed inGeneral Advanced Options(p. 948).

Include 2D Regions defined a CFX-TfC BFI file.CFX-5 will convert the imported regions into namedFluid Boundaries.

Select the file type for the imported mesh. You canselect from Formatted, Unformatted or Unknown. Ifyou select Unknown CFX-5 attempts to determinethe file type before importing the mesh.

This section of the form is generic for all Sources.See General Advanced Options (p. 948) for detailson this section.




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CFX-5.1

Import a mesh from a CFX-5.1 Results file (*.res). There are not anyoptions available specific to the CFX-5.1 format. See GeneralAdvanced Options (p. 948) for details on the generic option availableon this form.

GridPro/az3000

Import a volume mesh from a GridPro/az3000 ‘grid’ file (*.grid).

Import Grid Blocks as Sub-domains

For volume meshes which have predefined Sub-domains(3D Regions) you can select to keep their definition, or mergeSub-domain elements into a single Fluid Domain. Unlabelled 3Dregions are automatically grouped into a CFX-5 Sub-domain named‘UNLABELED_SUBDOMAIN’.

Convert predefined Periodic boundaries into CFX-5Fluid Boundaries on import.

Import grid blocks as discrete Sub-domains. Ignoringconnectivity does not equivalence nodes at grid blockinterfaces.

For each predefined grid block, create a separateCFX-5 Sub-domain.


Enabling will not import boundary conditions and2D and 3D regions and other data in the propertiesfile




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MSC/NASTRAN

Import a mesh from an MSC/NASTRAN file..

Include Sub-domains

When toggled OFF, all mesh elements are merged into a single FluidDomain. You can import each labelled 3D regions into a Sub-domainby turning this toggle ON. Unlabelled 3D regions are automaticallygrouped into a CFX-5 Sub-domain namedUNLABELED_SUBDOMAIN.

Pointwise Gridgen

Import a mesh from a Pointwise Gridgen file. There are not any optionsavailable specific to the Pointwise Gridgen format. See GeneralAdvanced Options (p. 948) for details on the generic option availableon this form.


When toggled OFF, all mesh elements are merged intoa single Fluid Domain.

“Distributed Loads” are pressure boundaries which, ifimported, are used to generate 2D Regions in CFX-5.




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Delete / Mesh Group

Highlight the Mesh Group containing an ImportedMesh to delete.

Toggle to view the selected mesh

Page 967 Delete / Mesh Group CFX-5.5.1



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Transform / Mesh

The Transform / Mesh form is used to place an imported mesh in therequired location. There are three basic transformations –Translations, Rotations and Scaling. A fourth transformation is alsoavailable called Position. The Position transformation maps threesource points to three destination points to achieve a transformation.More complex transformations can be performed by successiveapplication of the basic types.

Transform / Mesh / TranslateThe Translate method is used to move a Mesh Group by a translationalvector <dx dy dz>.

Select the Mesh Group to translate.

Select the coordinate frame to use as the reference forthe translation. You can enter the name of thecoordinate frame or pick a set of axes from theViewport. Coord 0 is the default Cartesian coordinateframe.

Enter a translational vector.

Enable to access a limited number of geometryoperations. You can define new Points and CoordinateFrames. See Creating Points, Curves, Surfaces andSolids (p. 281 in CFX-Build: Chapter 1) andCreating Coordinate Frames (p. 562 in CFX-Build:Chapter 1) .


Page 968 Transform / Mesh CFX-5.5.1



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Transform / Mesh / RotateThe Rotate method is used to rotate a Mesh Group by a specified angleabout a specified axis.

Select the Mesh Group to rotate.

Select the coordinate frame to use as the referenceframe. This is not used if an Axis is specified as anaxis of a coordinate frame.

Specify the axis of rotation using the formatCoord name.n where name is the name of thecoordinate frame (0 is the name for the defaultCartesian coordinate frame), and n can be 1, 2 or 3to specify the first, second or third axis of thecoordinate frame. You can also define an axis by twopoints in the Refer. Coordinate Frame using theformat {[x1 y1 z1][x2 y2 z2]} . For example{[0 0 0][0 0 1]} would define the z-axis whenusing the default coordinate frame.

Specify the angle of rotation in degrees aboutselected axis. The direction of rotation is clockwisewhen looking along the positive direction of theaxis.

Enable to access a limited number of geometryoperations. You can define new Points andCoordinate Frames. See Creating Points, Curves,Surfaces and Solids (p. 281 in CFX-Build:Chapter 1) and Creating Coordinate Frames(p. 562 in CFX-Build: Chapter 1) .





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Transform / Mesh / PositionThe Position method is used to transform a mesh group by definingthree original point locations and three destination point locations. Thetransformation can not be performed if either set of points define astraight line. You should also note that a unique transformation is notdescribed by this method, so entering the Original and DestinationPoints in a different order could result in a different transformation.

Select the Mesh Group to position.

Enter the Destination position for Point 1, Point 2and Point 3. You can type in coordinate positions(e.g. [0 0 1] ), type in Points names (e.g.Point 9 ) or pick existing Points from theViewport.

Enter the Original position for Point 1, Point 2 andPoint 3. You can type in coordinate positions (e.g.[0 0 1] ), type in Points names (e.g. Point 9 )or pick existing Points from the Viewport.

Enable to access a limited number of geometryoperations. You can define new Points andCoordinate Frames. See Creating Points, Curves,Surfaces and Solids (p. 281 in CFX-Build:Chapter 1) and Creating Coordinate Frames(p. 562 in CFX-Build: Chapter 1) .





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Transform / Mesh / ScaleThe Scale method is used to scale a mesh by a Scale Factor. You canincrease or decrease the size of the overall mesh by using the samescaling factor for each coordinate direction. By using different scalingfactors you can stretch the mesh in one coordinate direction

The scaling is achieved by multiplying the location of each mesh noderelative to the Origin of Scaling by the scaling vector.

Select the coordinate frame to use as the reference for thetranslation. You can enter the name of the coordinateframe or pick a set of axes from the Viewport. Coord 0 isthe default Cartesian coordinate frame.

Select the Mesh Group to scale.

Enter the Origin of Scaling as a coordinate (e.g.[0 0 0] ), a Point name (e.g. Point 1 ) or by picking anexisting Point from the Viewport.

Select the Scale Parameters option as:

• One Scale Factor : the mesh is scaled by the ScaleFactor value in the X, Y and Z coordinate directions.

• X,Y,Z Scale Factors : the mesh can be scaled bydifferent Scale Factor values in each coordinatedirection.

Enable to access a limited number of geometryoperations. You can define new Points and CoordinateFrames. See Creating Points, Curves, Surfaces andSolids (p. 281 in CFX-Build: Chapter 1) and CreatingCoordinate Frames (p. 562 in CFX-Build: Chapter 1) .





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