ANSYS2DF Interface

The import filter(ansys2df) for Ansys is primarily designed to read the Ansys "cdb" files and convert the data to IcemCFD unstructured mesh(domain), boundary condition(attribute) and solver parameter files. The filter is compatible with the ANSYS version 7.0.

The cdb files are generated from within Ansys with the CDWRITE command. The filter would need a cdb file generated with either "all", "comb" or "db" option. The format should be "BLOCKED". The detailed description of CDWRITE command is available in the Ansys documentation.

The import supports the conversion of the following Ansys data:
1. Nodes

2. Elements: (Ref: ANSYS 7.0 doc)
1-49,51-84,110-93,95-111,115-123,126-143,145-154,157-167, 169-178, 180-192, 195, 200
alongwith key options 1 through 6 as applicable.

The missing elements are not supported because of the following reasons:
MATRIX50 : A superelement, which in effect can be a set of any number of elements. No equivalent in IcemCFD mesh.
85 : Does not exist in ANSYS 7.0.
112-114: Non-existent.
CIRCU94,124,125 : Geometry doesn't have IcemCFD mesh equivalents. (Used for circuit simulation.)
ROM144 : Ditto as for CIRCU above. (Used for coupled electrostatic-structural system analysis.)
155,156,168 : Non-existent.
PRTES179 : Ditto as for CIRCU above. (Used to define pre-tension sections.)
INTER193,194 : Ditto as for CIRCU above. (Used for modeling structural assemblies.)

Note: The interface adds missing midside nodes for quadratic elements, if any.

3. All material properties as defined by MPDATA/MPTEMP commands.

4. Real constant data as defined by RLBLOCK commands.

5. Node and element components as defined by CMBLOCK commands are written out as subsets in the unstructured domain file.

6. Nodal DOF constraints(D), Forces/Moments (F), Surface loads(SF) & Body loads(BF).

During translation to IcemCFD mesh, each unique combination of material id, element type id and real constant set id generates a new family of elements.

The filter can also read the Ansys batch files (but is not recommended) within the following limitations:

  • Can interpret only N, E, ET & TYPE commands. ( NBLOCK & EBLOCK commands are not supported. Also it can read only upto first 8 nodes specified in E command. Any additional nodes with EMORE generate warnings. This implies that it does not support any of the quadratic volume elements.)
  • Cannot handle degenerate elements.

  • These limitations also apply to those Ansys batch files as generated by the Ansys output interface of the IcemCFD/AI*Environment.

    The command line for ansys2df is invoked with the following arguments:
    -d <specify the prefix for the project files to be written>
    <specify the name of Ansys cdb/batch(not recommended) input file>

    Any input filename without the .cdb extension is parsed as a batch input file.