1.4. CFX-Pre File Types

The following file types are used by or produced by CFX-Pre:

Case Files (.cfx)

The case file contains the physics data, region definitions, and mesh information for the simulation and is used by CFX-Pre as the 'database' for the simulation setup. The case file is generated when you save a simulation in CFX-Pre. To re-open a simulation, select File > Open Case and pick a case file to open.

When you import a mesh into CFX-Pre, it passes through an import filter and is stored as part of the case file. Therefore, once a mesh has been imported, the original mesh file is not required by CFX-Pre. Additional information on importing meshes is available in Importing Meshes.

The case file is a binary file and cannot be edited directly.

You can open cases on any supported platform, regardless of the platform on which they were created.

Mesh Files

There are many types of mesh files that can be imported into CFX-Pre. For details, see Supported Mesh File Types.

CFX-Solver Input Files (.def, .mdef)

A CFX-Solver input file is created by CFX-Pre. The input file for a single configuration simulation (.def) contains all physics and mesh data; the input file for a multi-configuration or operating point simulation (.mdef) contains global physics data only (that is, Library and Simulation Control CFX Command Language specifications). An .mdef input file for a multi-configuration simulation is supplemented by Configuration Definition (.cfg) files that:

  • Are located in a subdirectory that is named according to the base name of the input file

  • Contain local physics and mesh data.

Note:  Use the -norun command line option (described in Command-Line Options and Keywords for cfx5solve in the CFX-Solver Manager User's Guide) to merge global information into the configuration definition files, and produce a CFX-Solver input file (.def) that can be run by the CFX-Solver.

You can load a CFX-Solver input file back into CFX-Pre to recreate a simulation. CFX-Solver input files from previous releases of Ansys CFX can be loaded into CFX-Pre, although the physics definition may have to be updated for such files. For details, see Physics Errors from Old .def/.res Files.

CFX-Solver Results Files (.res, .mres, .trn, .bak)

Intermediate and final results files are created by the CFX-Solver:

  • Intermediate results files, which include transient and backup files (.trn and .bak, respectively) are created while running an analysis.

  • Final results files for single-configuration simulations (.res), multi-configuration simulations (.mres), and operating point simulations (.mres) are written at the end of the simulation’s execution. For a multi-configuration simulation, a configuration result file (.res) is also created at the end of each configuration’s execution. For an operating point simulation, a result file (.res) is also created at the end of each operating point job.

Each results file contains the following information as of the iteration or time step at which it is written:

  • The physics data (that is, the CFX Command Language specifications)

  • All or a subset of the mesh and solution data.

CFX-Solver Backup Results Files (.bak)

A backup file (.bak) is created at your request, either by configuring the settings on the Backup tab in Output Control in CFX-Pre, or by choosing to write a backup file while the run is in progress in the CFX-Solver Manager.

CFX-Solver Transient Results Files (.trn)

A transient results file (.trn) is created at your request, by configuring the settings on the Output Control > Trn Results tab in CFX-Pre.

CFX-Solver Error Results Files (.err)

An error results file (.err) is created when the CFX-Solver detects a failure and stops executing an analysis. The .err file can be loaded into CFD-Post and treated the same way as a .bak file, but if the CFX-Solver encounters another failure while writing the .err file, it may become corrupted and accurate solutions cannot be guaranteed.

Session Files (.pre)

Session files are used by CFX-Pre to record CFX Command Language (CCL) commands executed during a session. The commands can be played back at a later date to reproduce the session. These files are in ASCII format and can be edited or written in a text editor. For details, see New Session Command.

CCL Files (.ccl)

CFX CCL files are used by CFX-Pre to save CFX Command Language (CCL) statements. CCL files differ from session files in that only a snapshot of the current state is saved to a file. These files are in ASCII format and can be edited or written in a text editor. The CCL statements stored in these files replace or append the existing CCL data, depending on the option chosen. For details, see:

An overview of the files used throughout Ansys CFX is available in Ansys CFX File Types in the CFX Introduction.