The Fluid Flow (CFX) system performs fluid-flow analysis of incompressible and compressible fluid flow and heat transfer in complex geometries.
This system is also used as part of the FSI: Fluid Flow (Ansys CFX) > Static Structural custom system.
This analysis is configured in Ansys CFX.
For detailed information on working with Ansys CFX, see Ansys CFX in Ansys Workbench.
To work through a Fluid Flow (CFX) system:
To add a Fluid Flow (CFX) analysis system, drag the system from the Toolbox to the Project Schematic or double-click the system in the Toolbox.
To load the geometry, right-click the Geometry cell and select one of the following options from the context menu:
To create a mesh, right-click the Mesh cell and select from the context menu.
Right-click the Setup cell and select one of the following options from the context menu:
To specify the Ansys CFX physics definitions in CFX-Pre, select .
To import a previously saved case file, select > .
Right-click the Solutions cell and select one of the following options from the context menu:
To start the solver immediately, select .
To set the solver execution controls in CFX-Solver Manager select .
To import an existing CFX-Solver Results file, select > .
To analyze the results of the calculations in CFD-Post, right-click the Results cell and select from the context menu.
Note: If you import a CFX-Solver Input File into a CFX Setup
cell and the reload file format is not a CFX-Solver Input File (for example, a
DEF file) and the Reload Options were not defined or did
not contain a replacetype option, you may need to modify
the definition of the Mesh Reload Options.
If a definition file contains a mesh from a GTM file and is imported into a Setup cell, the original mesh type is automatically changed to CFX-Solver Input file. If the remeshing process is not explicitly told to import the GTM file as a GTM file, the remeshing process assumes that the mesh is also a CFX-Solver Input file, rather than a GTM file.
This fails when the remeshing process runs. This is a limitation and must be modified by hand. To do this, add a line similar to the following to the DEF file:
Mesh Reload Options = "replacetype=GTM,notransform=false"
See Remeshing Tab in the CFX-Pre User's Guide for details.
If your CFX run fails and a backup file is available, you can resume a run from the latest standard or essential backup, or equivalent transient results file. This capability is especially useful for cases with very long runtimes to avoid restarting from initial conditions or, if the solver failed due to an error, reviewing backed up results to diagnose and correct the issue.
To take advantage of this capability, follow these steps when starting your run:
Import a case file or begin with an existing CFX setup definition.
Open Setup and define backups:
From the menu bar, select > > .
Switch to the Backup tab.
For more information on output controls and the Backup tab in CFX-Pre, see Output Control.
Define your backup settings.
Note that only or backup files provide sufficient data for a clean restart. Additional backup files using the or option can be included, but are not available for restarting a solution.
Close CFX-Pre.
In the Workbench Project Schematic, update the system to start the solution.
If the solver fails to write a results file, right-click the Solution cell and select from the context menu to resume the solution or to review the results in CFD-Post or keep the backup to use as initial conditions.
If you selected , the update continues from the last completed backup.
If you selected , a new CFX system with only a Solution cell and a new Results cell is created in the Project Schematic. You can review the results from this system to determine the status of the solution at the last completed backup point. From there, you can choose to resume the original interrupted run or you can choose to revise your original case as necessary.
Note: The solution is restarted directly from the backup file and includes any modifications made through the Command Editor. Also, if the setup is modified, is not available. To modify the setup and restart from a backup, first copy the backup to a new solution using and link this backup solution to your solution cell to use it as an initial guess.