Chapter 2 Introduction to Workbench and CFX Workflow

1. Chapter 2Introduction to Workbenchand CFX Workflow Introduction to CFX

2. The Toolbox The Project Schematic 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):

3. 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. The Toolbox

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. 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. The Project Schematic

7. The Project Schematic • 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). • 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.

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. By dropping the structural system at the “Solution” level we obtain a structural system that is coupled to the thermal solution. The Project Schematic 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 CFXsystem 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 CFX-Pre • 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, … CFD-Post CFX-Solver • In WB Edit the Setup entry to start CFX-Pre • Four types of simulation are available

22. CFX-Pre – Workspace CFX-Pre CFD-Post CFX-Solver 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 • 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 CFD-Post CFX-Solver • Analysis Type • Steady State / Transient • 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. Useful Shortcuts Rotate + CTRL Pan Viewer Toolbar Zoom + SHIFT (Hold while tracing a box) Box Zoom Rotate (on screen plane) + CTRL

25. CFX-Pre – Workflow Example CFX-Pre • Load Mesh • Right-click on Mesh CFD-Post CFX-Solver 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 CFX-Pre • Define Domain Properties • Right-click on the domain and pick Edit • Or right-click on Flow Analysis 1 to insert a new domain CFD-Post CFX-Solver 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 CFX-Pre • Create Boundary Conditions for a Domain • Right-click on the domain to insert BC’s CFD-Post CFX-Solver After completing the boundary condition, it appears in the Outline tree below its domain

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

29. CFX-Pre – Workflow Example CFX-Pre • Start Solver CFD-Post CFX-Solver • 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 CFX-Pre • 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! CFD-Post CFX-Solver

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

32. CFX-Solver Manager CFX-Pre • When the Solver finishes, start CFD-Post: CFD-Post CFX-Solver • When running standalone: • Enable Post-Process Results on the solver finished notification window • Or select the Post-Process Results icon from the toolbar • 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 Right-click to start CFD-Post

33. CFD-Post CFX-Pre • Workspace CFD-Post CFX-Solver • 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 CFX-Pre • 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 CFD-Post CFX-Solver • i) Generate qualitative data at locationsii) Generate quantitative data at locations • Generate Reports

35. CFD-Post CFX-Pre • Create Locations • Variables / Expressions • Qualitative and Quantitative data • Reports CFD-Post CFX-Solver 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(CFX-Pre Database) CFX-Pre .def(Solver Input or Definition File) .out(Solver Output File) CFX-Solver .res(Results File) .cst(CFD-Post State File).cse(CFD-Post Session File) .def, .cmdb(Mesh Files) CFD-Post

37. Import Mesh .cmdb, .cfx5, .def, .res, … Open .cfx, .def, .res .cfx(CFX-Pre Database) CFX-Pre .def(Solver Input or Definition File) .out(Solver Output File) CFX-Solver .res(Results File) .def, .cmdb(Mesh Files) .cst.cse CFD-Post Summary of Common File Types • .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 C:\Filename_001.out CFX-Solver C:\Filename_001 C:\Filename_001\100_full.bak First Time Solving Filename.def C:\Filename_001\1.trn C:\Filename_001\2.trn C:\Filename_001.res C:\Filename.def C:\Filename_002.out CFX-Solver 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. C:\StaticMixer.wbpj C:\StaticMixer_files Project files and folders. Do not edit directly 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

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 12.0Workflow 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