Introduction to CFXdl.ptecgroup.ir/.../cfd/ANSYS-CFX/CFX12_02_Intro_CFX.pdfand CFX Workflow Introduction to CFX Workbench and CFX Workflow 2-2 ANSYS, Inc. Proprietary © 2009 ANSYS,

2-1ANSYS, Inc. Proprietary

© 2009 ANSYS, Inc. All rights reserved.April 28, 2009

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Chapter 2

Introduction to Workbenchand CFX Workflow

Introduction to CFX

Workbench and CFX Workflow



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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




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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.




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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.




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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.




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• 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.




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• 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.




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• 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.).




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• 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.




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• 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.




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• 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




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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.




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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.




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• From the Workbench “View” menu activate the

“Files” option to display a window containing file

details and locations.




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• 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.




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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




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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




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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)




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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




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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




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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




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Training Manual

Outline Tree

Viewer Window

Main Menu

Message Window

Viewer Toolbar

CFX-Pre – Workspace

Main Toolbar





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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





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Training ManualUseful Shortcuts

Viewer Toolbar

Rotate

Pan + CTRL

Zoom + SHIFT

Box Zoom

Rotate(on screen plane)

+ CTRL

(Hold while

tracing a box)




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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.





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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





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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





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Training Manual

4. Define Solver Settings

– Right-click on Solver Control and pick Edit


All solver

controls have

default values





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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





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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




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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





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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





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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




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Training Manual

• General Workflow

1. 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-Post





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Training ManualCFD-Post

CFD-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




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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




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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




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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.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.res

Second Time

Solving

Filename.def




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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




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Training ManualLicense Preferences

• Workbench license control is handled through the user interface

shown below, activated from the Workbench project page (“Tools >

License Preferences . . . “).




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• 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.




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• 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).



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ANSYS CFX 12.0Workflow Demo




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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