文档库 最新最全的文档下载
当前位置:文档库 › Icepak-v12.0-tut-09

Icepak-v12.0-tut-09

Tutorial9.Inline or Staggered Heat Sink Introduction:This tutorial demonstrates how to use the check-box(boolean)param-eter control for design variables,and how to assign primary functions,in order to determine whether an inline or a staggered pin?n heat sink performs better in a sin-gle model.The resulting maximum temperature on the package will be compared.

Non-conformal meshing will also be employed to reduce the cell count,required memory,and run time.In addition,particle traces passing a non-conformally meshed assembly will be presented during the post-processing of the results.

In this tutorial you will learn how to:

?De?ne a check-box parameter(design variable).

?De?ne di?erent values for a design variable.

?Run and report parametric trials.

?Clip a plane cut to align it with the sides of a heat sink assembly.

?Display particle traces coming from the fan and the opening.

Prerequisites:This tutorial assumes that you are familiar with the menu structure in ANSYS Icepak and that you have solved or read Tutorial1.Some steps in the setup and solution procedure will not be shown explicitly.

Problem Description:The model includes the Package assembly,containing a BGA package object(compact conduction model),Inline or Staggered assemblies consist-ing of the respective heat sink objects,PCB object,Spreader plate,a fan at the exit,and an opening at the inlet of the wind tunnel.The model geometry is shown in Figure9.1.

Inline or Staggered Heat Sink

Figure9.1:Problem Speci?cation

Step1:Create a New Project

1.Copy the?le

ICEPAK ROOT/tutorials/heat sink/heat sink2b.tzr

to your working directory.You must replace ICEPAK ROOT by the full path name

of the directory where ANSYS Icepak is installed on your computer system.

2.Start ANSYS Icepak,as described in Section1.5of the User’s Guide.

When ANSYS Icepak starts,the New/existing panel will open automatically.

3.Click Unpack in the New/existing panel.

The File selection panel will appear.

4.In the File selection panel,select the packed project?le heat-sink2b.tzr and click

Open.

The Location for the unpacked project?le selection dialog will appear.

5.In the Location for the unpacked project?le selection dialog,select a directory where

you would like to place the packed project?le,enter a project name in the New

project text?eld,then click Unpack.

Inline or Staggered Heat Sink

Step2:Build the Model

This tutorial uses an existing model.ANSYS Icepak will display the heat sink model in the graphics window.To view all components,expand all the assemblies of the model in the Model manager window.

You can rotate the cabinet around a central point using the left mouse button,or you can translate it to any point on the screen using the middle mouse button.You can zoom into and out from the cabinet using the right mouse button.To restore the cabinet to its default orientation,select Home position from the Orient menu.

Save the problem to a new project?le.

This will allow you to expand on the problem without a?ecting the original?le.

File?→Save project as

?In the Project text box,enter the name heat-sink-new.

?Click Save.

Step3:De?ne Design Variables

For both heat sinks,you will de?ne the HeatSink parameter,which will activate/deactivate heat sinks parametrically.

1.De?ne the HeatSink parameter for the Inline heat sink.

(a)Select the Inline assembly in the Model manager window,and then click the

Edit object button()to open the Assemblies panel.

(b)Click the Info tab.

Inline or Staggered Heat Sink

(c)Right-click the Active check box to open the Active parameter panel.

(d)Select Option is ON if variable is equal to this object’s name.

(e)Enter$HeatSink in the Variable name text box.

Note that all function names are case sensitive.

(f)Click Accept in the Active parameter panel to accept the changes and close the

panel.

(g)Click Update in the Assemblies panel to open the Param value panel.

Inline or Staggered Heat Sink

(h)In the Param value panel,enter Staggered for the Initial value of HeatSink,and

click Done to close the panel.

Note that the word Active in the Assemblies panel became green.Also,note

that the Inline assembly in the Model manager window is moved to the Inactive

node.

(i)Click Done in the Assemblies panel to close the panel.

2.De?ne the HeatSink parameter for the Staggered heat sink.

(a)Repeat above steps for the Staggered assembly.

You will not have to specify the initial value again.

Step4:De?ne Parametric Runs and Assign Primary Functions

You will?rst de?ne values for your design variable.Next,you will review parametric trials and de?ne primary functions to be calculated and reported.

Solve?→Run optimization

Extra:Alternatively,you can click the button.

1.De?ne parameter values.

(a)In the Parameters and optimization panel,click the Design variables tab.

(b)Expand the HeatSink parameter from the list to view the de?ned variables.

(c)Next to Discrete values,enter"Inline"with a space,after"Staggered".

(d)Click Apply to accept the changes.

Inline or Staggered Heat Sink

Inline or Staggered Heat Sink

2.Review trials.

(a)Click the Trials tab.

(b)Make sure that Inline Order is1,and Staggered Order is2.

Inline or Staggered Heat Sink

3.De?ne a primary function.

(a)Click the Functions tab.

(b)Click the New button under Primary functions.

(c)In the De?ne primary function panel,enter Tmax next to Function name.

(d)In the Pre-de?ned function drop-down list,select Maximum temperature of ob-

jects.

(e)Under Pre-de?ned function,in the Object drop-down list,select the BGA object

under Package,and click Accept.

Inline or Staggered Heat Sink

(f)In the De?ne primary function panel,click Accept to save the changes and close

the panel.

(g)Click Done in the Parameters and optimization panel to close the panel.

Step5:Generate a Mesh

For this model,you will not generate a mesh in advance.Meshing will be automatically performed for each design trial during the parametric trials.

Model?→Generate Mesh

1.Keep all the defaults in the Mesh control panel.

2.Under Global settings,make sure that the Mesh assemblies separately option is turned

on.

Inline or Staggered Heat Sink

3.Click Close in the Mesh control panel to close the panel.

Step6:Physical and Numerical Settings

De?ne basic parameters.

Problem setup?→Basic parameters

?Keep all the defaults in the Basic parameters panel.

?Click Accept in the Basic parameters panel to accept the settings and close the panel.

Step7:Save the Model

ANSYS Icepak will save the model for you automatically before it starts the calculation, but it is a good idea to save the model(including the mesh)yourself as well.If you exit ANSYS Icepak before you start the calculation,you will be able to open the project you saved and continue your analysis in a future ANSYS Icepak session.(If you start the calculation in the current ANSYS Icepak session,ANSYS Icepak will simply overwrite your project?le when it saves the model.)

File?→Save project

Step8:De?ne Monitor Points

It is always a good approach to de?ne monitor points before starting to run a simulation.

In this model,a monitor point was already de?ned by dragging the BGA package object into the Points node in the Model manager window.In addition to the residual plot,the monitor plot will display temperature at the center of the BGA package object during the solution process and provide an indication of convergence.

Step9:Calculate a Solution

1.Open the Parameters and optimization panel,if it is not already opened.

Solve?→Run optimization

Note that you can click the button in the Model and solve toolbar.

Inline or Staggered Heat Sink

2.Click the Setup tab,and make sure that options Parametric trials and All combina-

tions are selected.

3.Click Run in the Parameters and optimization panel,to start the calculations.

As ANSYS Icepak starts calculating solutions for the model,the Solution residuals window,displaying convergence history,and the Temperature Point monitors window will open.Also,the Parametric trials panel will open displaying the function values, as well as parameters and running times for both trials,as shown in Figure9.2.

The Parametric trials can also be opened by selecting Show optimization/param results from the Report menu.

Figure9.2:The Parametric trials Panel

Step10:Examine the Results

1.Display velocity vectors on a plane cut at the exit region of the heat sink.

Post?→Plane cut

Extra:You can also open the Plane cut panel by clicking the button.

(a)In the Orient menu,select Orient negative Z.

(b)In the Name?eld,enter the name cut-velocity.

(c)In the Set position drop-down list,select Vertical-screen select.

(d)Select a point in the graphics window between the fan and the heat sink

assembly.

(e)Turn on the Show vectors option,and click Parameters to open the Plane cut

vectors panel.

(f)In the Plane cut vectors panel,under Color levels,select Calculated,then select

This object from the drop-down list.

Inline or Staggered Heat Sink

(g)Select Project to plane.

(h)Click Apply in the Plane cut vectors panel to accept the changes.

(i)Click the Create button and Done to close the panel.

(j)In the Orient menu,select Isometric view.

The graphics window will be updated,as shown in Figure9.3

Figure9.3:Velocity Vectors at the Exit Region of the Heat Sink

Inline or Staggered Heat Sink

2.Clip the plane cut to align it with the sides of the heat sink assembly.

(a)In the Orient menu,?rst select Orient positive X,then Scale to?t.

(b)Unexpand the Staggered assembly node in the Model manager window,if it was

expanded,in order to see the edges of the assembly in the graphics window.

(c)In the Plane cut panel(that was already opened),select Enable clipping,then

click Max Y in the orange region under Clip to box.

(d)Click the top red edge of the assembly in the graphics window.

(e)In the Plane cut panel,click Min Z in the orange region under Clip to box.

(f)Click the left red edge of the assembly in the graphics window.

(g)In the Plane cut panel,click Max Z in the orange region under Clip to box.

(h)Click the right red edge of the assembly in the graphics window.

(i)Click the Update button.

The graphics window will be updated,as shown in Figure9.4

Figure9.4:Clipped Plane Cut

Inline or Staggered Heat Sink

3.Display particle traces in a forward direction.

(a)In the Orient menu,select Isometric view.

(b)In the Plane cut panel,unselect Show vectors and select Show particle traces.

(c)Click Parameters next to Show particle traces to open the Plane cut particles

panel.

(d)Select Speed from the Variable drop-down list.

(e)Under Display options,select Uniform,and enter50.

(f)Under Style,keep the default selection of Dye trace Width and select Particles

with Radius2.

(g)Under Color levels,select Calculated,then select This object from the drop-down

list.

(h)Click Apply to update the graphics panel.

The graphics window will display the particle traces in the forward direction,

as shown in Figure9.5

Figure9.5:Forward Particle Traces

Inline or Staggered Heat Sink

4.Display particle traces at the opening(Xmax).

(a)In the Orient menu,select Orient negative Z.

(b)In the Plane cut panel,select New.

(c)In the Name?eld,enter the name opening-velocity.

(d)In the Set position drop-down list,select Vertical-screen select.

(e)Select a point in the graphics window near the opening(Xmax).

(f)Turn on the Show particle traces option,and click Parameters to open the Plane

cut particles panel.

(g)Select Speed from the Variable drop-down list.

(h)Under display options,select Uniform,and enter50.

(i)Under Style,keep the default selection of Dye trace Width and select Particles

with Radius2.

(j)Under Color levels,select Calculated,then select This object from the drop-down list.

(k)Click Apply to update the graphics window.

(l)Click Done in the Plane cut particles panel to close the panel.

(m)Click Done in the Plane cut panel to close the panel.

Step11:Summary

In this tutorial,you used the optimization tool to determine whether an inline or a staggered pin?n heat sink performs better in a single model.The resulting maximum temperature on the package was found to be higher in the case of the staggered heat sink.

Inline or Staggered Heat Sink

相关文档