cfx12 02 intro cfx

2-1ANSYS, Inc. Proprietary© 2009 ANSYS, Inc. All rights reserved.

April 28, 2009Inventory #002598

Chapter 2

Introduction to Workbenchand CFX Workflow

Introduction to CFX

Workbench and CFX Workflow



Training ManualThe 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




Training ManualThe 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.




Training ManualThe 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.




Training ManualThe 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.





• 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.





• 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.





• 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.).




Training ManualThe 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.





• 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.





• 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




Training ManualOptional 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.




Training ManualWorkbench 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.





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





• 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.




Training ManualStarting 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




Training ManualTry 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




Training ManualRunning 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)




Training ManualRunning 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




Training ManualSetting 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




Training Manual

CFD-PostCFX-Pre CFX-Solver

Setup / 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, …

• In WB Edit the Setup entry to start CFX-Pre– Four types of simulation are available




Training Manual

Outline Tree

Viewer Window

Main Menu

Message Window

Viewer Toolbar

CFX-Pre – Workspace

Main Toolbar





Training Manual

• 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

CFX-Pre – WorkflowMesh and region control• Import, delete,

transform meshes• View & edit mesh

regions

Library objects• Optional. Referenced elsewhere in the setup• Import Materials & Reactions from libraries

provided• Insert Expressions, AV’s, Fortran routines

Solver settings• Convergence controls• Results files controls• Numerical schemes• Monitor points

Initialisation• Starting point for the solver

in the absence of a previous solution

Boundary Conditions

Domain• Right-click to insert

boundary conditions

Analysis Type• Steady State / Transient





Training ManualUseful Shortcuts

Viewer Toolbar

Rotate

Pan + CTRL

Zoom + SHIFT

Box Zoom

Rotate

(on screen plane)

+ CTRL

(Hold while tracing a box)




Training Manual

1. Load Mesh– Right-click on Mesh

CFX-Pre – Workflow Example

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.





Training Manual

2. Define Domain Properties– Right-click on the domain and pick Edit– Or right-click on Flow Analysis 1 to insert a new domain


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





Training Manual

3. Create Boundary Conditions for a Domain• Right-click on the domain to insert BC’s


After completing the boundary condition, it appears in the Outline tree below its domain





Training Manual

4. Define Solver Settings– Right-click on Solver Control and pick Edit


All solver controls have default values





Training ManualCFX-Pre – Workflow Example

• 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

5. Start Solver

Right-click to solve





Training Manual

• 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-Solver Manager




Training ManualCFX-Solver Manager

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

• WorkspaceCreate new monitors





Training ManualCFX-Solver Manager

• When the Solver finishes, start 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





Training Manual

Outline Tree

Viewer Window

Details Pane


CFD-Post

• Workspace

Outline tree displays all post-processing objects. Right-click or double-click to edit in the Details Pane

Editor Tabs• Outline• Variables• Expressions• Calculators• Turbo




Training Manual

• General Workflow1. Prepare locations where data

will be extracted from or plots generated• E.g. Planes, Isosurface

2. Create variables/expressions which will be used to extract data (if necessary)• E.g. drag, pressure ratio

3. i) Generate qualitative data at locations

ii) Generate quantitative data at locations

4. Generate Reports

CFD-PostCFD-PostCFX-Pre CFX-Solver




Training ManualCFD-PostCFD-PostCFX-Pre CFX-Solver1. Create Locations

2. Variables / Expressions

3. Qualitative and Quantitative data

4. Reports

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




Training ManualSummary of Common File Types

CFX-Solver

CFX-Pre

CFD-Post

.def (Solver Input or Definition File)

.cfx (CFX-Pre Database)

.wbpj (Workbench Project File)

.out (Solver Output File)

.res (Results File)

.cst (CFD-Post State File)

.cse (CFD-Post Session File).def, .cmdb (Mesh Files)

Import Mesh

.cmdb, .cfx5, .def, .res, …

Open

.cfx, .def, .res




Training ManualSummary 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-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-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




Training ManualSolver Files and Folders

CFX-Solver

C:\Filename.def

C:\Filename_001.out

C:\Filename_001

C:\Filename_001\100_full.bak

C:\Filename_001\1.trnC:\Filename_001\2.trn

C:\Filename_001.res

First Time Solving Filename.def

CFX-Solver

C:\Filename.def

C:\Filename_002.out

C:\Filename_002

C:\Filename_002\100_full.bak

C:\Filename_002\1.trnC:\Filename_002\2.trn

C:\Filename_002.res

Second Time Solving

Filename.def




Training ManualFile 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




Training ManualLicense Preferences

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




Training ManualLicense 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.




Training ManualLicense 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).



ANSYS CFX 12.0Workflow Demo




Training ManualWorkflow 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

cfx12 02 intro cfx

Documents

current working

common file

workbench

solver output

working directory

project file

outline tree

license control