1. Chapter 2 Introduction to Workbench and CFX Workflow
Introduction to CFX

2. The Workbench Environment
For most situations the Workbench GUI is divided into 2 primary sections (there are other optional sections we’ll see in a moment):
The Toolbox
The Project Schematic

3. The Toolbox The toolbox contains 4 subgroups: Analysis systems:
Predefined templates that can be placed in the schematic.
Component systems:
Various applications that can be accessed to build, or expand, analysis systems.
Custom Systems:
Predefined analysis systems for coupled applications (FSI, thermal-stress, etc.). Users can also create their own predefined systems.
Design Exploration:
Parametric management and optimization tools.

4. The Toolbox
The systems and components displayed in the toolbox will depend on the installed products.
Using the check boxes in the “View All / Customize” window, the items displayed in the toolbox can be toggled on or off.
The toolbox customization window is normally left closed when not in use.

5. The Project Schematic
The Workbench project schematic is a graphical representation of the workflow defining a system or group of systems.
The workflow in the project schematic is always left to right.
There are currently several applications which are native to Workbench, meaning they run entirely in the Workbench window:
Project Schematic, Engineering Data and Design Exploration
Non-native applications (called data-integrated) run in their own window:
Mechanical (formerly Simulation), Mechanical APDL (formerly ANSYS), ANSYS Fluent, ANSYS CFX, Etc . . .
Blocks of cells can be deleted by RMB menu selection.

6. The Project Schematic
In this example a Static Structural analysis type is selected for the project schematic.
From the toolbox the selection can be dragged and dropped onto the schematic or simply double clicked.

7. The Project Schematic
By dropping applications and/or analyses into various locations in the schematic, an overall analysis project is defined.
“Connectors” indicate the level of collaboration between systems.
In the example shown a structural system is dragged and dropped onto a thermal system at the Model cell (A4).
Before completing the operation notice there are a number of optional “drop” locations that will provide various types of linkage between systems (continued next page).

8. The Project Schematic
By completing the operation from the previous page, notice the linkage here is only at the Model level and above.
In this case there would be no thermal/structural coupling.
Notice too each system block is given an alphabetic designation (A, B, C, etc.).

9. The Project Schematic
By dropping the structural system at the “Solution” level we obtain a structural system that is coupled to the thermal solution.
Notice, the candidate “drop” location indicates data will be shared from fields A2 to A4, and transferred from A6.

10. The Project Schematic
A schematic can also be constructed by RMB and choosing to “Transfer Data To New” or “Transfer Data From New”.
In using the RMB transfer feature all transfer possibilities (upstream and downstream) are displayed.
These selections will vary depending on which cell in a particular system you highlight.

11. The Project Schematic Identifying cell states:
Unfulfilled: missing upstream data.
Attention required: may need to correct this or upstream cells.
Refresh required: upstream data has changed. Need to refresh cell. An update will also refresh the cell and regenerate any output data (e.g. mesh, results).
Update required: the data has changed and the output of the cell must be regenerated.
Up to date.
Input changes pending: cell is locally up to date but may change when the next update is performed due to upstream changes.
Interrupted: solver was manually stopped before it finished. Can use Resume or Update to continue to solving.
Pending: a batch process is in progress

12. Optional Workbench Windows
The “View” menu (and RMB) allows additional information to be displayed in the Workbench environment.
Below, the geometry is highlighted and the properties are displayed.

13. Workbench File Management
Workbench creates a project file and a series of subdirectories to manage all associated files.
Users should allow Workbench to manage the directories.
Please do NOT manually modify the content or structure of the project directories.
When a project is saved a project file is created (.wbpj), using the user specified file name (e.g. MyFile.wbpj).
A project directory will be created using the project name. In the above example the directory would be MyFile_files.
A number of subdirectories will be created in the project directory.

14. Workbench File Management
From the Workbench “View” menu activate the “Files” option to display a window containing file details and locations.

15. Workbench File Management
Archive: quickly generates a single compressed file containing all pertinent files.
File is zip format and can be opened using the “Restore Archive ” utility in WB2 or any unzip program.
Several options are available when archiving systems as shown here.

16. Starting CFX CFX can be launched from: The CFX 12.0 Launcher
Start > All Programs > ANSYS 12.0 > CFX > ANSYS CFX 12.0
Within ANSYS Workbench
Drag ‘Analysis Systems > Fluid Flow (CFX)’ or ‘Component Systems > CFX’ onto the Project Schematic
The command line
More common under Linux/Unix

17. Try It Yourself! Now launch Workbench on your training machine…
Start > All Programs > ANSYS 12.0 > ANSYS Workbench
Expand the Component Systems toolbox and add a CFX system to the Project Schematic
Drag a second CFX system onto the Project Schematic, dropping it onto the Solution cell of the first
The first Solution is used as the starting point for the second Solution, e.g. a steady-state run followed by a transient run
Right-click on the Setup cell in the first system and select Edit
This will open CFX-Pre
You can leave CFX-Pre open for now

18. Running Standalone vs Workbench
Running CFX inside the Workbench environment:
Simplifies the workflow
Geometry, Mesh, Setup, Solution and Results steps shown on the Project Schematic
Easier to update a project when a change is made
E.g. after a geometry change a single click updates the Mesh, Setup, Solution and Results
Allows you to easily link to other Analysis Systems and Components
Is necessary when performing DesignExploration (parametric studies)

19. Running Standalone vs Workbench
Running CFX standalone:
Less computational overhead
Produces a simpler directory / file structure on disk
But no direct association between geometry, mesh, setup and results files
Each component must be updated
No built-in automation for parametric studies
Less automation
E.g mesh needs to be manually imported into CFX-Pre

20. Setting the Working Directory
Before starting a project you should set the working directory
Avoids files getting saved to ‘Documents and Settings’
From the CFX Launcher specify the Working Directory before starting Pre / Solver / Post
In Workbench Save the project before adding anything to the Project Schematic

21. Setup / CFX-Pre In WB Edit the Setup entry to start CFX-Pre
CFX-Solver
CFD-Post
In WB Edit the Setup entry to start CFX-Pre
Four types of simulation are available
General mode is the general purpose mode for defining all types of CFD simulations
When running in Workbench CFX-Pre will automatically start in this mode
Turbomachinery mode simplifies the setup for rotating machines
Quick Setup mode greatly simplifies the physics setup for a simulation by assuming many default parameters and basic physics
Library Template mode provides a predefined setup for complex physics
Boiling, cavitation, coal & oil combustion, …

22. CFX-Pre – Workspace CFX-Pre CFX-Solver CFD-Post Main Menu Main Toolbar
Viewer Toolbar
Outline Tree
Viewer Window
Message Window

23. CFX-Pre – Workflow
Mesh and region control
Import, delete, transform meshes
View & edit mesh regions
CFX-Pre
CFX-Solver
CFD-Post
Analysis Type
Steady State / Transient
To define your simulation, generally follow the Outline tree from top to bottom
Double-click entries in the Outline tree to edit
Right-click on entries in the Outline tree to insert new items or perform operations
Some items are optional, depending on your simulation
Domain
Right-click to insert boundary conditions
Boundary Conditions
Initialisation
Starting point for the solver in the absence of a previous solution
Solver settings
Convergence controls
Results files controls
Numerical schemes
Monitor points
Library objects
Optional. Referenced elsewhere in the setup
Import Materials & Reactions from libraries provided
Insert Expressions, AV’s, Fortran routines

24. (Hold while tracing a box)
Useful Shortcuts
Rotate
Pan
+ CTRL
Viewer Toolbar
Zoom
+ SHIFT
(Hold while tracing a box)
Box Zoom
Rotate
(on screen plane)
+ CTRL

25. CFX-Pre – Workflow Example
CFX-Solver
CFD-Post
Load Mesh
Right-click on Mesh
A Default Domain is automatically created when the mesh is imported. It contains all 3D regions in the mesh.
Every domain contains a default boundary condition.

26. CFX-Pre – Workflow Example
Define Domain Properties
Right-click on the domain and pick Edit
Or right-click on Flow Analysis 1 to insert a new domain
CFX-Pre
CFX-Solver
CFD-Post
When editing an item a new tab panel opens containing the properties. You can switch between open tabs.
Sub-tabs contain various different properties
Complete the required fields on each sub-tab to define the domain
Optional fields are activated by enabling a check box

27. CFX-Pre – Workflow Example
Create Boundary Conditions for a Domain
Right-click on the domain to insert BC’s
CFX-Pre
CFX-Solver
CFD-Post
After completing the boundary condition, it appears in the Outline tree below its domain

28. CFX-Pre – Workflow Example
Define Solver Settings
Right-click on Solver Control and pick Edit
CFX-Pre
CFX-Solver
CFD-Post
All solver controls have default values

29. CFX-Pre – Workflow Example
Start Solver
CFX-Pre
CFX-Solver
CFD-Post
When running in Workbench:
Just close CFX-Pre
Files are automatically saved
Check mark shown next to Setup
Right-click on Solution and select Edit or Refresh
Refresh runs the solver in the background with default settings
Edit opens the Solver Manager
When running standalone:
You should manually save the CFX-Pre database
Right-click on Simulation and select Start Solver >
Define Run opens the Solver Manager
Run Solver runs in the background with default settings
Run Solver and Monitor run with default settings and monitors in the Solver Manager
Right-click to solve

30. CFX-Solver Manager Defining a Run
CFX-Pre will have written a .def file and this is automatically selected as the Solver Input File
Can enable Initial Values check box if you have a previous solution to use as the starting point
Parallel settings are defined here
Allows you to divide a large CFD problem so that it can run on more than one processor/machine
Start Run!
CFX-Pre
CFX-Solver
CFD-Post

31. CFX-Solver Manager Workspace CFX-Pre CFX-Solver CFD-Post
Create new monitors
Solution Monitors
Monitor the convergence of the solver
Plot residuals, imbalances, monitor points, forces, fluxes…
Text output from the Solver
Lots of info in here
Can also view the .out file in a text editor

32. CFX-Solver Manager When the Solver finishes, start CFD-Post:
CFX-Pre
CFX-Solver
CFD-Post
When running in Workbench:
Just close the Solver Manager
Check mark shown next to Solution
Right-click on Results and select Edit to start CFD-Post
When running standalone:
Enable Post-Process Results on the solver finished notification window
Or select the Post-Process Results icon from the toolbar
Right-click to start CFD-Post

33. CFD-Post Workspace CFX-Pre CFX-Solver CFD-Post Editor Tabs
Outline
Variables
Expressions
Calculators
Turbo
Outline Tree
Outline tree displays all post-processing objects. Right-click or double-click to edit in the Details Pane
Details Pane
Viewer Window

34. CFD-Post General Workflow
Prepare locations where data will be extracted from or plots generated
E.g. Planes, Isosurface
Create variables/expressions which will be used to extract data (if necessary)
E.g. drag, pressure ratio
CFX-Pre
CFX-Solver
CFD-Post
i) Generate qualitative data at locations ii) Generate quantitative data at locations
Generate Reports

35. CFD-Post Create Locations Variables / Expressions
Qualitative and Quantitative data
Reports
CFX-Pre
CFX-Solver
CFD-Post
Use the Location drop-down menu in the toolbar to create locations inside the domain
2D & 3D domain, boundary and mesh regions are automatically available
Discussed in the Post-processing lecture along with more details on creating locations

36. Summary of Common File Types
.wbpj (Workbench Project File)
Import Mesh
.cmdb, .cfx5, .def, .res, …
Open
.cfx, .def, .res
CFX-Pre
.cfx (CFX-Pre Database)
.def (Solver Input or Definition File)
CFX-Solver
.out (Solver Output File)
.res (Results File)
.cst (CFD-Post State File) .cse (CFD-Post Session File)
.def, .cmdb (Mesh Files)
CFD-Post

37. Summary of Common File Types
CFX-Solver
CFX-Pre
CFD-Post
.def (Solver Input or Definition File)
.cfx (CFX-Pre Database)
.out (Solver Output File)
.res (Results File)
.cst .cse
.def, .cmdb (Mesh Files)
Import Mesh
.cmdb, .cfx5, .def, .res, …
Open
.cfx, .def, .res
.cfx files contain mesh and physics data and can be opened by CFX-Pre
.def files contain mesh and physics data and can be run in the Solver
.res files contain mesh, physics and results data and can be opened in CFD-Post
CFX-Pre can also open .def and .res files to recover the mesh and physics. Some unused data (e.g. unused Materials) is not written to the .def / .res files and is therefore not recovered.
The CFX-Solver can use .res files to continue a run or as an initial guess
CFD-Post can also open .def and .cmdb files to view the mesh

38. Solver Files and Folders
C:\Filename.def
CFX-Solver
C:\Filename_001.out
C:\Filename_001
First Time Solving Filename.def
C:\Filename_001\100_full.bak
C:\Filename_001\1.trn
C:\Filename_001\2.trn
C:\Filename_001.res
C:\Filename.def
CFX-Solver
C:\Filename_002.out
C:\Filename_002
Second Time Solving Filename.def
C:\Filename_002\100_full.bak
C:\Filename_002\1.trn
C:\Filename_002\2.trn
C:\Filename_002.res

39. File Structure in Workbench
When running CFX standalone, files are saved to your current working directory
As noted on the previous side, some solver files are saved to a solver run directory
When running in Workbench only the project file (.wbpj) is saved to the current working directory
All other files are saved to a name_files subdirectory
C:\StaticMixer.wbpj
C:\StaticMixer_files
Project files and folders. Do not edit directly

40. License Preferences
Workbench license control is handled through the user interface shown below, activated from the Workbench project page (“Tools > License Preferences “).

41. License Preferences
With the available licenses displayed, the activation and “use order” can be specified using the up/down arrows.
0 = off, 1 = on
License order represents the preference order for license use.
The license control allows Workbench users to specify whether a single license is used when multiple applications are open, or if all open applications access their own license.

42. License Preferences
In the example shown, a user could have 3 Mechanical models open simultaneously. Using the license control they may choose to open 3 licenses or use only 1 that is shared. In the shared scenario, only the active Mechanical session uses the license (the remaining will be read only).

43. ANSYS CFX 12.0 Workflow Demo

44. Workflow Demo
Your instructor will now perform a quick demonstration of the workflow in a simple CFX project
This simulation sets up the Static Mixer simulation – the first of the tutorials supplied with the ANSYS CFX documentation
The mesh for this simulation can be found in the examples directory of your CFX installation and can be imported as a CFX-Solver Input mesh file
By default: C:\Program Files\ANSYS Inc\v120\CFX\examples\StaticMixer.def