CFX 5.5 V5.5.1H
? 2001AEA Technology
2-1
Completing a CFD Simulation
Using CFX-5
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-2
CFX-5 Modeling Approach
? Create a solid which defines the region of interest.
? Define the fluid domain in terms of flow region,physical models,and
fluid properties.
? Apply boundary conditions to fluid domain surfaces.
? Specify an initial guess/condition for the simulation.
? Create a mesh for the fluid domain.
? Set the solver parameters which will be used by the solver.
? Write a definition file containing the model information,This includes
mesh information,physical properties,boundary conditions,etc...
? Use the solver manager to run the solver and monitor the solution.
? View the results with CFX-Post.
? This approach will be followed in the practical sessions.
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-3
Introduction
? Purpose:
to work through a complete CFD solution process as a hands-on
exercise
to introduce the CFX-5 User Interface
? Detailed instructions for the exercise are provided
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-4
Problem Definition
? Water flowing through a simple duct bend will be modelled
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-5
Starting CFX-5
On PC
? CFX-5 has been started for you (by double-clicking on the CFX-5 icon on
the Desktop) to work in the course directory for this course
? Click Browse..,and create a new Directory Name,called duct to become
the working directory
On Unix
? Make a working directory
mkdir duct
? Change to the working directory
cd duct
? Start CFX-5
cfx5
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-6
Starting CFX-Build
? Click on CFX-Build
? Create a new database
From the top menu,pull down File and New
Add duct to the path in the New Database Name field
Click on OK
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-7
New Model Preferences
? In the New Model Preferences menu:
Choose Generate Mesh as
Meshing Mode,(This is the default)
Set the Geometry Dimensions to
inch (in)
Use a Global Model Tolerance of
0.005
Click on OK
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-8
? Select the Geometry radio button from the top window
? We are going to create the bounding surfaces and then a B-rep solid
? The following directions are shown using the Action/Object/Method
syntax
? On each form,press -Apply- to execute the action
Geometry
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-9
Geometry
Show labels Point size
Turn on the Show labels and Point size icons
from toolbar icons
Create/Point/XYZ,at [0 1 0] and [0 4 0]
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-10
Create/Curve/Point,connect 2 points with a curve
Geometry
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-11
? Create/Surface/Revolve,revolve along the z-axis
(Axis Coord 0.3) with 90 degree angle,select the curve
Geometry
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-12
? Create/Surface/Extrude,set the translation vector
to <8 0 0> and select the same curve
Geometry
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-13
Geometry
? Create/Surface/Extrude,set the translation vector to
<0 -4 0> and choose the low y edge of the bend
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-14
Geometry
? Create/Surface/Extrude,set the translation vector to
<0 0 1> and select all 8 side curves (exclude two
internal curves)
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-15
Geometry
? Create/Curve/Chain,select all 8 curves in the high-z
direction
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-16
Geometry
? Create/Surface/Trimmed,select planar option and
enter the newly created curve in the outer loop list and
delete the original curve
* You may want to use entity selection filter to choose the
explicit curve
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-17
Geometry
? Create/Solid/B-rep,pick all surfaces
? Check the Delete Original Surfaces option
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-18
Fluid Domain
? Select the Domains radio button from the top menu
? Create a fluid domain called duct
Under the Domain Options menu,enter Reference
Pressure of 101325 Pa
Select Water at RTP from the Available Fluids list
Select the solid for the Bounding Solids
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-19
Boundary Conditions
? Select the Boundary Conditions radio button
? Create a boundary condition called in
Set the Type to Inlet
Specify Values
Normal Speed in 10.0 ft/s (change the units by
clicking the small icon next to the units field)
Use the default turbulence values
Select the low y face of the duct
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-20
Boundary Conditions
? Create a boundary condition called out
Set Type to Outlet
Specify the relative pressure under the Values
form to be 0.0 Pa
Choose the high x face of the duct
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-21
Boundary Conditions
? Create a boundary condition called sym1
Set the type to Symmetry Plane
Select the high z faces of the duct
? Create a second symmetry boundary called
sym2
Select the low z faces of the duct
? Any other exterior surfaces not explicitly
chosen as part of a defined B.C,will be
defined as a default boundary condition,The
default B.C,is a stationary no-slip wall
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-22
Initial Values
? Choose the Initial Guess radio button
For this example all automatic
initial values should be suitable so
no changes are necessary
Click on -Apply-
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-23
Surface Mesh
? Choose Mesh radio button.
Select Set/Mesh Param.
> Set Maximum Edge Length to 0.25,All other
settings as default and now click on -Apply-.
Select Create/Surface Mesh.
> Toggle on Display Mesh.
> Press Apply.
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-24
Solver Parameters
? Select the Solver Control radio button
Click on Convergence Control button
Change the maximum number of
timesteps to 50,Close the form
Press -Apply-
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-25
Definition File
? Select the Definition File radio button
Set the definition file name to duct.def
Toggle on Write Mesh
Toggle on Shutdown CFX-Build
Choose Start Solver Manager
Press Apply
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-26
Solver Manager
? Once the CFX-5 Solver Manager
appears,click the Start button
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-27
Solver Manager
? When the CFX-5 run has finished,click on OK.
? Select the CFX-Post icon and choose Run Post with results.
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-28
Post-processing
? Choose the New Vector
Plot button from the
Toolbar
Select OK to name
the plot Vector 1
? In the Object Editor,set
Location
> Sym1
Check the Visibility
Box
Apply
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-29
Post-processing
? Choose the New
streamline button from
the Toolbar
Select OK to name
the plot Streamline 1
? In the Object Editor,set
Location
> In
Check the Visibility
Box
Apply
? 2001AEA Technology
2-1
Completing a CFD Simulation
Using CFX-5
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-2
CFX-5 Modeling Approach
? Create a solid which defines the region of interest.
? Define the fluid domain in terms of flow region,physical models,and
fluid properties.
? Apply boundary conditions to fluid domain surfaces.
? Specify an initial guess/condition for the simulation.
? Create a mesh for the fluid domain.
? Set the solver parameters which will be used by the solver.
? Write a definition file containing the model information,This includes
mesh information,physical properties,boundary conditions,etc...
? Use the solver manager to run the solver and monitor the solution.
? View the results with CFX-Post.
? This approach will be followed in the practical sessions.
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-3
Introduction
? Purpose:
to work through a complete CFD solution process as a hands-on
exercise
to introduce the CFX-5 User Interface
? Detailed instructions for the exercise are provided
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-4
Problem Definition
? Water flowing through a simple duct bend will be modelled
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-5
Starting CFX-5
On PC
? CFX-5 has been started for you (by double-clicking on the CFX-5 icon on
the Desktop) to work in the course directory for this course
? Click Browse..,and create a new Directory Name,called duct to become
the working directory
On Unix
? Make a working directory
mkdir duct
? Change to the working directory
cd duct
? Start CFX-5
cfx5
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-6
Starting CFX-Build
? Click on CFX-Build
? Create a new database
From the top menu,pull down File and New
Add duct to the path in the New Database Name field
Click on OK
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-7
New Model Preferences
? In the New Model Preferences menu:
Choose Generate Mesh as
Meshing Mode,(This is the default)
Set the Geometry Dimensions to
inch (in)
Use a Global Model Tolerance of
0.005
Click on OK
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-8
? Select the Geometry radio button from the top window
? We are going to create the bounding surfaces and then a B-rep solid
? The following directions are shown using the Action/Object/Method
syntax
? On each form,press -Apply- to execute the action
Geometry
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-9
Geometry
Show labels Point size
Turn on the Show labels and Point size icons
from toolbar icons
Create/Point/XYZ,at [0 1 0] and [0 4 0]
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-10
Create/Curve/Point,connect 2 points with a curve
Geometry
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-11
? Create/Surface/Revolve,revolve along the z-axis
(Axis Coord 0.3) with 90 degree angle,select the curve
Geometry
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-12
? Create/Surface/Extrude,set the translation vector
to <8 0 0> and select the same curve
Geometry
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-13
Geometry
? Create/Surface/Extrude,set the translation vector to
<0 -4 0> and choose the low y edge of the bend
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-14
Geometry
? Create/Surface/Extrude,set the translation vector to
<0 0 1> and select all 8 side curves (exclude two
internal curves)
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-15
Geometry
? Create/Curve/Chain,select all 8 curves in the high-z
direction
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-16
Geometry
? Create/Surface/Trimmed,select planar option and
enter the newly created curve in the outer loop list and
delete the original curve
* You may want to use entity selection filter to choose the
explicit curve
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-17
Geometry
? Create/Solid/B-rep,pick all surfaces
? Check the Delete Original Surfaces option
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-18
Fluid Domain
? Select the Domains radio button from the top menu
? Create a fluid domain called duct
Under the Domain Options menu,enter Reference
Pressure of 101325 Pa
Select Water at RTP from the Available Fluids list
Select the solid for the Bounding Solids
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-19
Boundary Conditions
? Select the Boundary Conditions radio button
? Create a boundary condition called in
Set the Type to Inlet
Specify Values
Normal Speed in 10.0 ft/s (change the units by
clicking the small icon next to the units field)
Use the default turbulence values
Select the low y face of the duct
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-20
Boundary Conditions
? Create a boundary condition called out
Set Type to Outlet
Specify the relative pressure under the Values
form to be 0.0 Pa
Choose the high x face of the duct
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-21
Boundary Conditions
? Create a boundary condition called sym1
Set the type to Symmetry Plane
Select the high z faces of the duct
? Create a second symmetry boundary called
sym2
Select the low z faces of the duct
? Any other exterior surfaces not explicitly
chosen as part of a defined B.C,will be
defined as a default boundary condition,The
default B.C,is a stationary no-slip wall
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-22
Initial Values
? Choose the Initial Guess radio button
For this example all automatic
initial values should be suitable so
no changes are necessary
Click on -Apply-
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-23
Surface Mesh
? Choose Mesh radio button.
Select Set/Mesh Param.
> Set Maximum Edge Length to 0.25,All other
settings as default and now click on -Apply-.
Select Create/Surface Mesh.
> Toggle on Display Mesh.
> Press Apply.
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-24
Solver Parameters
? Select the Solver Control radio button
Click on Convergence Control button
Change the maximum number of
timesteps to 50,Close the form
Press -Apply-
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-25
Definition File
? Select the Definition File radio button
Set the definition file name to duct.def
Toggle on Write Mesh
Toggle on Shutdown CFX-Build
Choose Start Solver Manager
Press Apply
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-26
Solver Manager
? Once the CFX-5 Solver Manager
appears,click the Start button
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-27
Solver Manager
? When the CFX-5 run has finished,click on OK.
? Select the CFX-Post icon and choose Run Post with results.
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-28
Post-processing
? Choose the New Vector
Plot button from the
Toolbar
Select OK to name
the plot Vector 1
? In the Object Editor,set
Location
> Sym1
Check the Visibility
Box
Apply
CFX 5.5 V5.5.1H
? 2001AEA Technology
2-29
Post-processing
? Choose the New
streamline button from
the Toolbar
Select OK to name
the plot Streamline 1
? In the Object Editor,set
Location
> In
Check the Visibility
Box
Apply
