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Thermal Analysis Using MSC.Nastran

NAS104 EXERCISE WORKBOOKMSC.Nastran Version 70.7

MSC.Patran Version 9.0

NA*70.7*Z*Z*Z*SM-NAS104-WBK

May 2000

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MSC.Nastran 104 Exercise Workbook 0-3

TABLE OF CONTENTS

Lesson Title

1. Getting Started

1a. Creating A Model

1b. Transient Thermal Analysis

2. Free Convection on Printed Circuit Board

3. Forced Convection on Printed Circuit Board

4. Thermal Contact Resistance

5. Typical Avionics Flow

6. Radiation Enclosures

7. Axisymmetric Flow in a Pipe

8. Directional Heat Loads

9. Thermal Stress Analysis from Directional HeatLoads

10. Thermal Stress Analysis of a Bi-Metallic Plate

Appendix Title

A Transient Thermal Analysis of a Cooling Fin

B. Analytical Solution for a Simple Radiation toSpace Problem

C. Printed Circuit Board using 2 1/2 D PavedMeshing Method

D. Create Group and List

E. Importing IGES File and Auto_Tet Mesh theModel

0-4 MSC.Nastran 104 Exercise Workbook

MSC.Nastran 104 Exercise Workbook 1a-1

Getting Started Creating A Model

WORKSHOP 1a

Objectives:

� Create a new database defined for MSC.Nastran thermal analysis.

� Define geometry for a rectangular plate.

1a-2 MSC.Nastran 104 Exercise Workbook

Getting Started – Creating A Model


WORKSHOP 1a

Model Description:In this exercise you will first create a aluminum plate. Shown belowis a drawing of the model you will be building and suggested stepsfor its construction.

Figure 1a.1

1 m

3 m

Aluminum Plate

K = 204 W/m-oC

Cp = 896 J/kg-oC

ρ = 2707 kg/m3

q = 5000.0 W/m2

T = 50 oC

Tamb = 20.0 oC

h = 10.0 W/m2-oC

Thickness = 0.1 m




WORKSHOP 1a

Suggested Exercise Steps:

� Create a new database defined for MSC.NASTRAN thermal analysis.

� Define geometry for a rectangular plate.

� Mesh the structure with quadrilateral elements.

� Modify the mesh.

� Define the plate’s material as aluminum. Specify a thermal conductivity of 204 W/m-oC, specific heat of 896 J/kg-oC, and a density of 2707 kg/m3.

� Define the plate’s thickness to be 0.1 m.

� Clean up the display.

� Apply a temperature of 50 oC to the bottom edge of the plate.

� Apply heat flux of 5000 W/m2 to the right edge of the plate.

� Apply to the left edge of the surface a convection boundary condition with heat transfer coefficient of 10.0 W/m2-oC and ambient temperature of 20 oC.

� Perform a steady-state thermal analysis using MSC.NASTRAN within the MSC.PATRAN system.

� Visualize the temperature distribution as a contour plot.




WORKSHOP 1a

Exercise Procedure:

1. Open a new database. Name it ex1a.

The viewport (PATRAN’s graphics window) will appear along witha New Model Preference form. The New Model Preference setsall the code specific forms and options inside MSC.PATRAN.

In the New Model Preference form set the Analysis Code toMSC.Nastran

2. Create the Model.

3. Mesh the surface with elements.

File/New...

New Database Name: ex1a

OK

Tolerance: � Based on Model

Analysis Code: MSC/NASTRAN

Approximate Maximum Model Dimension: 10.0

Analysis Type: Thermal

OK

� Geometry

Action: Create

Object: Surface

Method: XYZ

Vector Coordinates List: <1 3 0>

Origin Coordinates List: [0 0 0]

Apply

� Finite Elements

Action: Create

Object: Mesh


At this point, we will invoke MSC.PATRAN’s undo feature so thatwe can make a coarser mesh. The mesh we have just created (300elements) is excessive for our example.

Your model should look like the following figure.

At this point, we will invoke MSC.PATRAN’s undo feature so wecan make a coarser mesh. The mesh we have just created (300elements) is excessive for our example.

Click on the Undo icon.

Click on the Refresh Graphics icon.

Type: Surface

Global Edge Length: 0.1

Mesher: IsoMesh

Surface List: Surface 1

Apply

X

Y

Z

Undo

Reset Graphics



WORKSHOP 1a

Note that the Finite Elements form is still visible. Change theGlobal Edge Length from 0.1 to 0.2. This will create elements of 0.2units (meters) in length, which will result in a coarser mesh of 75quadrilateral elements.


4. Specify Material Properties.

Our material for this exercise will be aluminum. Click on theMaterials application. The Material form will appear with certaindefault options.

� Finite Elements


Apply

� Materials

Action: Create

Object: Isotropic

Method: Manual Input

Material Name: alum

XYZ


5. Our next task is to specify a thickness of 0.1 to our aluminumelements.

From the Element Properties form, click on the Select Membersdatabox. MSC.PATRAN will display two icons to the left of theElement Properties form. The first icon represents surface or face,the second represents 2D element. The two options allow you toapply properties either on the geometric entity (in this case, thesurface) or on the finite elements.

Click on the Surface or Face icon.

Now click anywhere on the geometric surface. The surface will behighlighted in red. The Select Members databox will now appear asSurface 1.

Input Properties...

Thermal Conductivity: 204

Specific Heat: 896

Density: 2707

Apply

Cancel

� Properties

Action: Create

Object: 2D

Type: Shell

Property Set Name: plate

Input Properties...

Material Name: m:alum

Thickness: 0.1

OK

Add

Surface or Face



WORKSHOP 1a

6. Apply the load and boundary conditions.

Click on the Curve or Edge icon.

With your mouse, position the cursor on the bottom edge of thesurface. Click on the edge. You will see Surface 1.4 appear in theSelect Geometry Entities databox. This means we have selectedEdge number 4 in Surface number 1.

7. We will now apply heat flux to the model using the Loads/BoundaryConditions form.

Apply

� Load/BCs

Action: Create

Object: Temp(Thermal)

Type: Nodal

New Set Name: tempbc

Input Data...

Boundary Temperature: 50

OK

Select Application Region...

Geometry Filter: � Geometry

Add

OK

Apply

� Load/BCs

Action: Create

Object: Applied Heat

Type: Element Uniform

Curve or Edge


Because the problem is a 2D one, we need to toggle that TargetElement Type setting to 2D. Even though we are applying heat fluxalong an edge, which we normally think of as 1D, our finite elementproblem is 2D; i.e., we are modeling heat conduction in twodimensions.

Click on the Edge icon.

Position the cursor over the right edge of the surface and click on thisedge with the mouse. MSC.PATRAN will insert Surface 1.3 in thedatabox under the heading Select Surfaces or Edges.

A yellow flag will appear on the right edge of your surface indicatingthat a heat flux of 5000 W/m2 has been applied along the rightedge.

Option: Normal Fluxes


New Set Name: flux

Target Element Type: 2D

Input Data...

Form Type: Basic

Surface Option: Edge

Edge Heat Flux: 5000

OK



Add

OK

Apply

Edge



WORKSHOP 1a


8. We will now apply a convention boundary condition to the left edgeof the plate-- again, using the Loads/BCs form.

� Load/BCs

Action: Create

Object: Convention


Option: To Ambient


New Set Name: conv


Input Data...


Edge Convection Coef: 10

Ambient Temperature: 20

OK

5000.

50.00XYZ 5000.50.00


Click on the Edge icon.

Position the cursor over the left edge of the surface and click on theedge with the mouse. MSC.PATRAN will insert Surface 1.1 in thedatabox under Select Surfaces or Edges

A green label will appear confirming that you have applied aconvection coefficient of 10.0W/m2-oC at this location of yourmodel.




Add

OK

Apply

Edge

5000.

10.00

10.00

50.00XYZ 5000.50.00



WORKSHOP 1a

9. We are now ready to submit the model for MSC.NASTRAN steady-state thermal analysis. Click on the Analysis application located onthe MSC.PATRAN main form.

� Analysis

Action: Analyze

Object: Entire Model

Method: Analysis Deck

Job Name: ex1a

Apply


Submitting the Input File for Analysis:

10. Submit the input file to MSC.NASTRAN for analysis.

To submit the MSC.PATRAN .bdf file for analysis, find an availableUNIX shell window. At the command prompt enter: nastranex1a.bdf scr=yes. Monitor the run using the UNIX ps command.

11. When the run is completed, edit the ex1a.f06 file and search for theword FATAL. If no matches exist, search for the word WARNING.Determine whether existing WARNING messages indicatemodeling errors.



WORKSHOP 1a

12. MSC.Nastran Users have finished this exercise. MSC.PatranUsers should proceed to the next step.

13. Proceed with the Reverse Translation process, that is, attaching theex1a.xdb results file into MSC.Patran. To do this, return to theAnalysis form and proceed as follows:

14. Display the Results.

A contour plot displaying temperature distributions will appear.

� Analysis

Action: Attach XDB

Object: Result Entities

Method: Local

Select Results File...

Select Results File ex1a.xdb

OK

Apply

� Results

Select Results Cases:

Select Fringe Result:

Apply

Default, PW Linear: 100. % of Load

Temperatures



Select the Save and Close operations from the Fil menu to save yourplate.db file. We will perform a transient thermal analysis on thismodel in the next workshop.

15. Close database and quit MSC.Patran to complete this exercise.

File/Quit...

MSC.Nastran 104 Exercise Workbook 1b-1

Transient Thermal

WORKSHOP 1b

Objectives:

� Open the database created in Workshop 1a.

� Define time dependent funtions using the Field application.

� Create a trasient load case.

1b-2 MSC.Nastran 104 Exercise Workbook

Transient Thermal Analysis


WORKSHOP 1b

Model Description:This exercise describes transient thermal analysis, it is an extensionof the steady state modeling exercise given in Workshop 1a. Thisworkshop contains step-by-step descriptions of the menu picksinvolved in the modeling process.

Shown below is a drawing of the model you will be building andsuggested steps for its construction

Figure 1b.1

3 m

Aluminum Plate

k = 204 W/m-oC

Cp = 896 J/kg-oC

ρ = 2707 kg/m3

q = qflux(t) W/m2

T = 50 oC

Tamb = 20.0 oC

h = 10.0 W/m2-oC

Thickness = 0.1 m

1 m

q = qvol(t) W/m3

0.4 m

T0 = 50 oC




WORKSHOP 1b


� Open the database created in Workshop 1a.

� Define time dependent functions using the Field application.

� Create a transient load case. Add two existing load sets (temperature and convection boundary conditions) to this transient load case.

� Apply time varying heat flux to the right edge of the plate

� Apply a transient volumetric heat generation inside the shaded area of the plate

� Select solution type as transient analysis.

� Specify the default initial temperature.

� Define time steps.

� Select a transient load case.

� Perform a transient thermal analysis using MSC.NASTRAN within the MSC.PATRAN system

� Postprocess the transient results (Contour and XY plots).




WORKSHOP 1b

Exercise Procedure:

1. Open the database created in workshop 1a.

2. Define Time Dependent Functions.

Before applying time varying loads and boundary conditions, weneed to define time dependent functions using the Field application.In this model, two time fields are defined, one for applied heat fluxand one for volumetric heat generation.

Fill in the table with the following values using the RETURN orENTER key.

File/Open...

Existing Database Name: ex1a

OK

� Fields

Action: Create

Object: Non Spatial

Method: Tabular Input

Field Name: flux_time

Input Data...

Time(t): Value:

1:

0 1

2:

10 1.25

3:

30 1.75

4:

50 2

5:

100 2


Similarly, a time dependent function for volumetric heating isdefined as follows.

3. Create a transient load case.

OK

Apply

� Fields

Action: Create

Object: Non Spatial


Field Name: qvol_time

Input Data...

Time(t): Value:

1:

0 10000

2:

10 12000

3:

30 13000

4:

50 14000

5:

100 14000

OK

Apply

� Load Cases

Action: Create

Load Case Name: transient

Load Case Type: TimeDependent



WORKSHOP 1b

Since the temperature and convection boundary conditions are notchanged from Workshop 1a, we can associate these two load setswith the new load case directly.

Highlight Conve_conv and Temp_tempbc within the SelectIndividual Loads/BCs Sets listbox.

At this point, we will impose a transient flux load on the plate’s rightedge. The magnitude of this flux load is 5000 W/m2 multiplied bythe time dependent function flux_time defined earlier under theFields application. Click on the Loads/BCs application.

Assign/Prioritize Loads/BCs

OK

Apply

� Loads/BCs

Action: Create


Method: Element Uniform



New Set Name: tran_flux


Input Data...


Edge Heat Flux: 5000

Time Function: f:flux_time

OK


Select 2D Elements: Surface 1.3

Add

OK


4. Apply Transient Volumetric Heat Generation Inside the Plate.

The volumetric heating can be applied in a similar way, using theLoads and Boundary Conditions form as follows.

Next, click on Select Application Region located on the Loads andBoundary Conditions form. We want to apply an internal heatgeneration inside a section of the plate from x=0.0 m to x=0.4 m.This application region will be selected by graphical cursor using theFEM geometry filter.

Use the mouse cursor to drag a rectangle covering the elementslocated between x=0.0 m and x=0.4 m. Release the mouse cursor.The first two columns of the elements will turn red indicating theselection. Also, a list of elements will appear in the Select 2DElements databox.

Apply

� Loads/BCs

Action: Create


Method: Element Uniform

Option: VolumetricGeneration


New Set Name: tran_qvol


Input Data...

Time Function: f:qvol_time

OK


Geometry Filter: � FEM

Add

OK

Apply



WORKSHOP 1b

Note: A square yellow marker will appear on the center of theselected element indicating that a volumetric heating has beenapplied on this element.

5. Now we are ready to set the analysis controls for transient thermalanalysis.

For transient thermal analysis, we have to employ a startingtemperature from which the solution evolves. If the initialtemperature distribution is uniform, a default initial temperature issufficient to specify the initial state. Otherwise, the InitialTemperature object in Loads and BCs application must be used todefine initial nodal temperatures explicitly.

� Analysis

Action: Analyze



Job Name: ex1b

Solution Type...

� TRANSIENT ANALYSIS

Solution Parameters...

Default Init Temperature: 50.0

OK

OK

Subcase Create...

Available Subcase:

Subcase Parameters...

Initial Time Step: 10

Number of Time Steps: 100

OK

Apply

Cancel

Subcase Select...

transient


Subcases for Solution Sequence:

Subcases Selected:

OK

Apply

transient

Default



WORKSHOP 1b



6a. To submit the MSC.PATRAN .bdf file for analysis, find anavailable UNIX shell window. At the command prompt enter:nastran ex1b.bdf scr=yes. Monitor the run using the UNIXps command.

7. When the run is completed, edit the ex1a.f06 file and search for theword FATAL. If no matches exist, search for the word WARNING.Determine whether existing WARNING messages indicatemodeling errors.



9. Proceed with the Reverse Translation process, that is, attaching theex1b.xdb results file into MSC.Patran. To do this, return to theAnalysis form and proceed as follows:

Note: The heartbeat will change to the color blue, indicating thatreading process is underway. When the heartbeat turns green again,the results are ready for postprocess.

10. We will create a contour plot of temperature distributions attime=700 sec using the Results Display form.

� Analysis

Action: Attach XDB


Method: Local


Select Results File ex1b.xdb

OK

Apply

� Results

Action: Create

Object: Quick Plot

Select ResultsCases:

Select FringeResult:

Apply

Transient, Time=700

Temperatures



WORKSHOP 1b


Now we will apply XY plotting to visualize the temperature-timehistory of Nodes 49-54.

In the Select Result Case(s) listbox, click an drag mouse to selectthe time states from transient, Time=0, to transient, time=1020.

Within the Select Y Result listbox, highlight Temperatures.

Click on the Target Entities icon.

� Results

Action: Create

Object: Graph

Method: Y vs. X

Select Y Result:

Target Entity: Nodes

Temperatures

Target Entities


At this point, we will modeify the Y scale of the XY plot and displaygrid lines in the Y directly by clicking on the XY Plot application.

Select Nodes: Node 49:54

Apply

� XY Plot

Action: Modify

Object: Axis

Select Current XY Window: Results Graph

Active Axis: � Y

Scale...

Scale: � Linear

Assignment Method: � Range

Enter Lower and UpperValues:

45 70

Number of Primary TickMarks:

6

Apply

Cancel

Grid Lines...

Display: Primary

Apply



WORKSHOP 1b


11. Close the database and quit MSC.Patran when you have completedthis exercise.

File/Quit...



Free Convection on Printed Circuit Board

WORKSHOP 2

Objectives:

� Create surfaces for PCB and electronic devices.

� Apply thermal loads and boundary conditions.

� Perform a steady-state analysis.




WORKSHOP 2

Model Description:Shown below depicts a printed circuit board (PCB assembly whichhas three significant ship devices mounted on it. Each chip isgenerating heat at a rate that is consistent with the application of aheat flux of 5.0 W/in2 over each device surface area. Heat isdissipated by thermal conduction within the chips and underlyingboard. Free convection to the ambient environment provides theultimate heat take. The ambient temperature for convection isassumed to be 20.0 oC, and a heat transfer coefficient of 0.02 W/in2-oC is used to apply convection to the entire assembly surface. Wewill analyze the printed circuit board to determine the devicetemperature so that they can be compared to manufacturerallowables.

Shown below is a drawing of the model you will be building andsuggested steps for its construction.




WORKSHOP 2


� Create the Surfaces of Printed Circuit Board and Electric Components.

� Extrude the Surfaces to Create Solids.

� Mesh the Solids.

� Specify Materials.

� Define Element Properties.

� Merge the Common Nodes.

� Verify the Free Edges.

� Apply a heat load on each device.

� Apply a convection boundary condition on the PCB.

� Perform the Analysis.

� Read the analysis results.

� Display the results.




WORKSHOP 2

Exercise Procedure:

1. Create a New Database and name it free_conv_pcb.db.

2. Change the Tolerance to Default and the Analysis Code toMSC.Nastran in the New Model Preferences form. Verify that theAnalysis Type is Structural.

3. Create the surfaces of printed circuit board and electroniccomponents..

For Chip 1

File/New...

New Database Name free_conv_pcb.db

OK

New Model Preference

Tolerance Default


Analysis Type Thermal

OK

Geometry

Action: Create

Object: Surface

Method: XYZ

Surface ID List: 1

Vector Coordinates List: <9 6 0 >


Apply

Surface ID List: 2

Vector Coordinates List: <1 1.5 0>



.For Chip 2

For Chip 3

4. Create the PCB solid by extruding surfaces 1 by -0.1 inch in the Zdirection. Extrude surfaces.2,3 and 4 in the Z direction by 0.25inches.

If the Auto Execute is ON, you do not need to click on Apply.

For Chips 1, 2, 3:

Apply

Surface ID List: 3



Apply

Surface ID List: 4


Origin Coordinates List: [5.5 2 0]

Apply

Geometry

Action: Create

Object: Solid

Method: Extrude

Solid ID List: 1

Translation Vector: <0 0 -0.1>


Apply

Solid ID List: 2

Translation Vector: <0 0 0.25>



WORKSHOP 2

5. You will now create the model’s finite elements.

To obtain a clearer view, select the isometric view by clicking on theIso View icon.

The mesh should look like this.

Surface List: Surface 2:4

Apply

Finite Elements

Action: Create

Object: Mesh

Type: Solid


Element Topology: Hex8

Solid List: Solid 1:4

Apply


6. For this model we will assume that the PCB and chips aremanufactured from the isotropic materials having constantconductivities.

Kpcb = 0.066 W/in-oCKchip = 2.24 W/in-oC

For chips 1, 2, 3:

7. For a solid model element properties are used to assign the materialsto the various parts of the model. .

Materials

Action: Create

Object: Isotropic


Material Name: pcb

Input Properties....

Thermal Conductivitiy 0.066

Apply

Materials

Action: Create

Object: Isotropic


Material Name: chip

Thermal Conductivity: 2.24

Apply

Properties

Action:

Dimension:

Type:

Property Set Name: pcb

Input Properties...

Create

3D

Solid



WORKSHOP 2

Chips 1, 2, 3

8. To verify that the correct material properties have been defined andassigned to the correct model locations, change the Action option toShow and create a scalar plot of the model’s materials.

Material Name: m:pcb

OK

Select Members: Solid 1

ADD

Apply

Input Properties...

Material Name: m:chip

OK

Select Members: Solid 2:4

ADD

Apply

Properties

Action: Show

Select Property: Material Name

Display Method Scalar Plot

Select Groups: �Current Viewport

Default Group

Apply


The scalar plot resembles the following.

9. The duplicate nodes located at the PCB and chip interfaces must bemerges.

10. To check the equivalence process you should verify the elementboundaries. If the model has been equivalenced properly you shouldsee a wireframe rendering of your model where only the free edgesare components of the wireframe image. Display the view to ensurethat the model has no cracks between elements.

Finite Elements

Action: Equivalence

Object: All

Method: Tolerance Cube

Equivalence Tolerance: 0.005

Apply

Finite Elements

Action: Verify

Object:

Test: Boundaries

Element



WORKSHOP 2

11. A heat flux will now be applied to the exposed plan from face of thechips.

Use the Free Face Select icon to help you pick the exposed chipfaces.

12. The convection boundary condition will now be applied to the backside of the PCB (side opposite the chips)..

Display Type: �Free Edges

Apply

Load/BCs

Action:

Object:

Type:


New Set Name: flux


Input Data...

Heat Flux: 5

OK


Geometry Filter: �Geometry

Select Solid Faces: Solid 2.6 3.6 4.6

Add

OK

Apply

Load/BCs

Create

Applied Heat

Element Uniform


Use the Free Face Select icon to help you pick the back face of thePCB.

13. Perform the Analysis.

Action:

Object:

Type:

Option:

New Set Name:

Target Element Type:

Input Data...

Convection Coefficient:

Ambient Temperature:

OK

Select Application Region

Geometry Filter: �Geometry

Select Solid Faces:

Add

OK

Apply

Analysis

Action:

Object:

Method:

Job Name: ex2

Solution Type...

Solution Type: � STEADY STATE ANALYSIS

Create

Convection

Element Uniform

To Ambient

conv

3D

0.02

20

Solid 1.6

Analyze

Entire Model

Full Run



WORKSHOP 2

An MSC.Nastran input file called ex2.bdf will be generated. Thisprocess of translating your model into an input file is called theForward Translation. The Forward Translation is complete when theHeartbeat turns green.

OK

Apply



14. Submit the input file to MSC.Nastran for analysis.

14a. To submit the MSC.Patran .bdf file, find an available UNIXshell window. At the command prompt enter nastran ex2.bdfscr=yes. Monitor the run using the UNIX ps command.

14b. To submit the MSC.Nastran .dat file, find an available UNIXshell window and at the command prompt enter nastran ex2scr=yes. Monitor the run using the UNIX ps command.

15. When the run is completed, edit the ex2.f06 file and search for theword FATAL. If no matches exist, search for the word WARNING.Determine whether existing WARNING messages indicatemodeling errors.



WORKSHOP 2


17. Proceed with the Reverse Translation process, that is, attaching thefin.xdb results file into MSC.Patran. To do this, return to theAnalysis form and proceed as follows:.

18. Display the results.

Analysis

Action: Attach XDB


Method: Local

Select Result Files....

Select Results File ex2.xdb

OK

Apply

Results

Object:



Apply

Quick Plot

Default, PW Linear: 100%..

Temperature


The result should resemble the following.

The heat generated by the electronic devices is conducted to theprinted circuit board, and then spread on the epoxy glass PCB. Thecooling mechanism is provided by a free convection heat exchangebetween the backside of the PCB and the ambient fluid that ismaintained at 20 oC. As a result, the largest electronic device has thehighest temperature. Because of their indentical size, the other twoelectronic chips possess nearly the same temperature distribution.


Forced Air Convection on Printed Circuit Board

WORKSHOP 3

Objective:

� Create Geometry from MSC.Patran

�




WORKSHOP 3

Model Description:We will model the previous PCB thermal analysis with forced air convection over the flat plate, using the Coupled Advection feature. The air temperature rises in the X direction as the fluid stream traverses the circuit board. The temperature dependency of the convection coefficient will be defined using a temperature dependent field

q = 20.0 W/in2

m = .

Tin = 20.0 oC

h = h(T) W/in2-oC

9.0 in

8.33E-3 lbm/sec

Z

X

X

Air

K = 6.66E-4 W/in-oCCp = 456.2 J/lbm-oC

ρ = 5.01E-5 lbm/in3

µ = 1.03E-6 lbm/in-sec




WORKSHOP 3


� Create a new database called forced_conv_pcb.db

� Create a solid that represents the electronic component and the printed circuit board.

� Mesh surfaces and curves with global edge length of 0.25 using Hex8 as element topology

� Merge nodes by using Equivalence method under Finite Elements.

� Use Free Edges to verify the Element Boundaries

� Input specify Material Properties for the chip, pcb, air, and flow tube.

� Define the solids’ properties using pcb and chip for their property names.

� Apply loads and boundary conditions to the model using Coupled Advection Feature to simulate the forced air convection on the back surface of PCB.

� Apply heat flux on each device using Element uniform and define the inlet Temperature of the fluid.

� Perform, read, and display the results




WORKSHOP 3

Exercise Procedure:

1. Create a New Database and name it forced_conv_pcb.db.

2. Change the Tolerance to Default and the Analysis Code toMSC.Nastran in the New Model Preferences form. Verify that theAnalysis Type is Thermal.

3. Create the surfaces representing the printed circucit board.

File/New...

New Database Name forced_conv_pcb

OK


Tolerance Default


Analysis Type thermal

OK

Geometry

Action: Create

Object: Surface

Method: XYZ


Origin Coordinates List: [ 0 0 0 ]

Apply

Vector Coordinates List: <1 1.5 0>


Apply




When you are finished your model should look like the one shownin the figure below.

4. Extrude the solid

Apply


Origin Coordinates List: <5.5 2 0>

Apply

Geometry

Action: Create

Object: Solid

Method: Extrude





WORKSHOP 3

5. Mesh the solids to create Hex8 element with global edge length 0.25.

Apply



Apply

Finite Elements

Action: Create

Object: Mesh

Type: Solid

Global Edge Length 0.25

Element Topology Hex8

Solid List Solid 1:4

Apply


Your model should appear like the one shown below.

6. Equivalence the Finite Elements to reduce the number of elementsby eliminating duplicate nodes.

7. Verify the Element Boundaries.

Finite Elements

Action: Equivalence

Object: All

Type: Tolerance Cube


Apply

Finite Elements



WORKSHOP 3

8. Create the isotropic material properties.

9. Create the model’s element properties assigning the material type tothe correct region of the model.

Action: Verify

Object: Element

Test: Boundaries

Display Type: � Free Edges

Apply

Materials

Action: Create

Object: Isotropic


Material Name: chip

Input Properties...

Constitutive Model: Solid properties


Apply

Material Name: pcb



Apply

Properties

Action: Create

Dimension: 3D

Type: Solid

Property Set Name: chip


10. Define Temperature Dependent Field.

Input Properties...

Material Name: m:chip

OK

Select Members: Solid 2:4

Add

Apply

Property Set Name: pcb

Input Properties...

Material Names: m:pcb

OK


Add

OK

Fields

Action: Create

Object: Material Property


Field Name: conv_temp

Active Independent Variables: Temperature (T)

Input Data....

Input Scalar Data: Hit Enter Key

T.Value

00.2

1000.3

2000.35

Add



WORKSHOP 3

11. Select two nodes to create a curve.

12. Define the location of the Air Stream.

13. Mesh the Airstream. preferably, the mesh size should be the same onthe air stream as on the PCB.

OK

Geometry

Action: Create

Object: Curve

Method: Point

select the Node Icon

Starting Point List: Node 938

Ending Point List: Node 1838

Apply

Geometry

Action: Transform

Object: Curve

Method: Translate


Curve List: Curve 1

Apply

Finite Element

Action: Create

Object: Mesh

Type: Curve


Note: The identical mesh size is not required, but may provide the most accurate model. The Closest Approach method will select the nearest neighboring structure and fluid nodes.

14. Specify the material properties of air.

15. Define flow tube properties.


Ending Point List: Bar2

Curve List: Curve 2

Apply

Materials

Action: Create

Object: Isotropic


Material Name: air

Input Properties...

Constitutive Model: Fluid properties

Thermal Conductivity: 6.66e-4

Specific Heat: 456.2

Density: 5.01e-5

Dynamic Viscosity: 1.03e-3

Apply

Properties

Action: Create

Dimension: 1D

Type: Flow Tube

Property Set Name: flow_tube

Input Properties...

Material Name: m:air



WORKSHOP 3

16. We will use the Coupled Advection Feature to simulate the forcedair convection on the back surface of PCB.

There are two application regions:

•The Structure Region (Application Region 1) can be 1D, 2D, or 3D. In this case we have a 3D structure, and the appropriate Target Ele-ment Type is 3D.

•The Second Application Region must be 1D, which represents the air-flow over the flat plate. In this case, select the curve along the X direction. MSC.PATRAN will then couple the fluid to the structure locally by the Closest Approach method.

Diameter at Node 1: 1.0

OK

Select Members Curve 2

Add

Apply

Load/BCs

Action: Create

Object: Convection


Options: Coupled Advection

New Set Name: flow_by_plate


Region 2: 1D

Input Data...

Temperature Function f:conv_temp

Mass Flow Rate: 8.33e-3

OK



17. Apply a Heat Flux on Each Device.

Geometry Filter: Geometry

Select Solid Surfaces: Solid 1.6

Active List for companion region

Add

Select Curves: Curve 2

Add

OK

Apply

Load/BCs

Action: Create



Options: Normal Flux

New Set Name: heat_flux


Input Data...

Heat Flux: 20

OK



Select Solid Surfaces Solid 2.6 3.6 4.6

Add

OK

Apply



WORKSHOP 3

18. Define the inlet Temperature of the fluid.

19. Define the Default Initital Temperature and Perform the analysis.

Load/BCs

Action: Create

Object: Temp (Thermal)

Type: Nodal

New Set Name: inlet_temp

Input Data...


OK



Select Geometry Entities: Point 35

Add

OK

Apply

Analysis

Action: Analyze


Method: Full Run

Job Name: ex3

Solution Type...


Data Deck Echo: Sorted

Default Init Temperature 100

OK

OK


An MSC.Nastran input file called fin.bdf will be generated. Thisprocess of translating your model into an input file is called theForward Translation. The Forward Translation is complete when theHeartbeat turns green.

Apply



WORKSHOP 3








23. Proceed with the Reverse Translation process, that is, attaching theex3.xdb results file into MSC.Patran. To do this, return to theAnalysis form and proceed as follows:


Analysis

Action: Attach XDB


Method: Local



OK

Apply

Results

Object: Quick Plot

Select Results Cases: Default, PW Linear: 100. % of Load

Select Fringe Result: Temperatures

Apply



WORKSHOP 3

Your Viewport will appear as follows.

The viewport may now be reset by clicking on the broom icon in themain window.

File/Quit...



Thermal Contact Resistance

WORKSHOP 4

Objective:


� Determine the maximum and minimum temperature on different sides of the circuit board.




WORKSHOP 4

Model Description:In this example we will model the contact resistance between two solids. In this case, the contact between an electronic component and a printed wiring board (PWB)--to determine the maximum temperature at the top of the chip and the temperature drop to the bottom of the wiring board.

T = 20.0 oC

5.0 in

5.0 inKpwb = 0.6 W/in-oC

Kchip = 1.34 W/in-oC

2.0 in

2.0 in

2.0 in

2.0 in

0.25 in

0.5 in

q = 10.0 W/in2

Contact Coefficient = 1.2 W/in2-oC

Y

X

X

Z




WORKSHOP 4


� Create a new database called thermal_contact_resistance.db

� Create a solid that represents the electronic component and the printed wiring board.

� Mesh surfaces and curves with global edge length of 0.25 using Hex8 as element topology


� Input specify Material Properties for both solids.

� Define the solids’ properties using pwb and chip for their property names.

� Apply loads and boundary conditions to the model.Contact resistance is modeled in MSC.Patran using the Convection-Coupled menu operation (select the bottom of the chip surface and the top of the printed wiring board to specify the thermal conductance between the two surfaces).

� Apply heat flux on the top Surface of the chip with Element Uniform Type.

� Using thermal temperature, the boundary condition is applied to the backside of the PWB.

� Perform, read, and display the results.




WORKSHOP 4

Exercise Procedure:

1. Create a New Database called thermal_contact_resistance.db.

2. Change the Tolerance to Default and the Analysis Code toMSC.Nastran in the New Model Preferences form. Verify that theAnalysis Type is Thermal..

3. Create the solid representing the wiring board and eletronicelements.

File/New...

New Database Name thermal_contact_resistance

OK


Tolerance Default



OK

Geometry

Action: Create

Object: Solid

Method: XYZ

Solid ID List: 1

Vector Coordinates List: <5 5 0.5>


Apply

Solid ID List: 2

Vector Coordinates List: <2 2 .25>


Apply


4. Mesh the solids to create Hex8 element with global edge length 0.25.

To obtain a clearer view, select Iso 1 View


Finite Elements

Action: Create

Object: Mesh

Type: Solid


Element Topology Hex8

Solid List Solid 1:2

Apply



WORKSHOP 4


6. Create the isotropic material properties using the material constantsspecify in figure.

Finite Elements

Action: Equivalence

Object: All



Apply

Materials

Action: Create

Object: Isotropic


Material Name: pwb

Input Properties...



Apply

Material Name: chip



Apply



8. Contact resistance is modeled in MSC.Patran using the ConvectionCoupled. This technique enables you to apply a connection throughconvection between two solid geometric faces without connectingthe structures with finite elements. One advantage of this method isthat mesh sizes between the two regions need not be congruent.MSC.Patran will automatically find the ambient points closest to thethermal contact area.

Properties

Action: Create

Dimension: 3D

Type: Solid

Property Set Name: pwb

Input Properties...

Material Name: m:pwb

OK


Add

Apply

Property Set Name: Chip

Input Properties

Material Names: m:chip

OK


Add

OK

Load/BCs

Action: Create

Object: Convection




WORKSHOP 4

Note: Arrows should be pointing downward into the printed wiringboard.

9. Apply a Heat Flux on the Top Surfaces of the chip.

Options: Coupled

New Set Name: coup_conv


Region 2: 3D

Input Data...

Convection Coefficient: 1.2

OK



Select Solid Faces: Solid 2.5

Add

Active List

Select Solid Faces: Solid 1.6

Add

OK

Apply

Load/BCs

Action: Create



Options: Normal Fluxes



Input Data...


Heat Flux: 10

OK



Select Solid Surfaces Solid 2.6

Select the Free Face Solid icon

Add

OK

Apply



WORKSHOP 4

10. Apply a temperature Boundary Condition on the backside of the

PWB.

11. Perform the analysis.

Load/BCs

Action: Create


Type: Nodal

New Set Name: tempbc

Input Data...


OK



Select Geometry Entities: Solid 1.5

Select the Surface or Face icon

Add

OK

Apply

Analysis

Action: Analyze


Method: Full Run

Job Name: ex4

Apply





WORKSHOP 4








15. Proceed with the Reverse Translation process, that is, attaching theex4.xdb results file into MSC.Patran. To do this, return to theAnalysis form and proceed as follows:.



Analysis

Action: Attach XDB


Method: Local



OK

Apply

Results

Object: Quick Plot

Select Results Cases: Default, PW Linear: 100. % of Load

Select Fringe Result: Temperature

Apply



WORKSHOP 4


File/Quit...



Typical Avionics Flow

WORKSHOP 5

Objective:

� Modeling this problem within the MSC.Patran and MSC.Nastran.

� This method allows the analyst an option to specify non-coincident mesh sizes on the structure and the fluid nodes.




WORKSHOP 5

Model Description:In this exercise, the compact heat exchanger is being modeled usingMSC.Patran. MSC.Patran can associate the structure nodes with thefluid nodes using a technique called the Closet Approach method.This method allows the analyst an option to specity non-coincidentmesh sizes on the structure and the fluid nodes. However, it isrecommended that you use an identical mesh size for a regularisoparametric rectangular mesh.




WORKSHOP 5


� Create a new database called avionics_flow.db.

� Create a new surface that has a total of five rectangular ducts.

� Mesh surfaces and curves with global edge length of 0.25


� Input specify Material Properties

� Define the thickness of four side walls that separte fluid channels.

� Apply loads and boundary conditions to the model.

� Perform analysis and read the analysis results.




WORKSHOP 5

Exercise Procedure:

1. Create a New Database and name it avionics_flow.db.


Whenever possible click ❑ Auto Execute (turn off).

3. Create the geometry that represents the the compact heat exchangerwith five rectangular ducts.

File/New...

New Database Name avionics_flow

OK


Tolerance Default



OK

Geometry

Action: Create

Object: Curve

Method: XYZ



Apply


You will now use Transformation to create the upper part of therectangular duct.

Finish the rectangular surface by creating verticals lines connectingthe two previous horizontal lines.

Extrude the surface.

Geometry

Action: Transform

Object: Curve

Method: Translate

Translation Vector: <0 0.5 0>

Curve List: Curve 1

Apply

Geometry

Action: Create

Object: Curve

Method: Point

Starting Point: Point 1

Ending Point: Point 3

Apply

Starting Point: Point 2

Ending Point: Point 4

Apply

Geometry

Action: Create

Object: Surface

Method: Extrude

Translation Vector <0 0 -10>

Curve list Curve 1:4



WORKSHOP 5

Use Iso 1 View Icon to obtain 3D view

Create another surface and translate it to another surface

Select the Surface Icon

Apply

Geometry

Action: Create

Object: Curve

Method: XYZ

Vector Coordinates List: <0 0 -10>

Origin Coordinates List: [ 0.5 0.25 0 ]

Apply

Geometry

Action: Transform

Object: Surface

Method: Translate

Translation Vector: <1 0 0>

Repeat Count: 4

Surface List: Surface 1 2 4

Apply


Translate the final curve to complete the rectangular duct

Select the Curve Icon


4. Mesh Surfaces 1 to 16 to create QUAD4 elements with global edgelength 0.25.

Geometry

Action: Transform

Object: Curve

Method: Translate


Repeat Count: 4

Curve List: Curve 5

Apply

Finite Elements

Action: Create



WORKSHOP 5

5. Similiarly, mesh Curves 5 to 9 with Bar2 element using a GlobalEdge Length of 0.25.


Object: Mesh

Type: Surface


Element Topology Quad 4

Surface List Surface 1:16

Apply

Finite Elements

Action: Create

Object: Mesh

Type: Curve


Element Topology: Bar2

Curve List: Curve 5:9

Apply



7. Create the isotropic aluminum material properties using the materialconstants.

Finite Elements

Action: Equivalence

Object: All



Apply

Materials

Action: Create

Object: Isotropic


Material Name: alum

Input Properties...



OK

Apply

Material Name: air

Input Properties...

Constitutive Model: Fluid properties

Thermal Conductivity: 6.66e-4

Specific Heat: 456.2

Density: 5.01e-5

Dynamic Viscosity-: 1.03e-6

OK



WORKSHOP 5

8. Create the model’s element properties assigning the material typeand element thickness to the correct region of the model. Use thenames of inner_wall, and outside_wall for the property names. TheThickness of the four side walls that separte fluid channels is 0.1inch. The other walls have a thikckness of 0.05 inch.

Select Front View Icon to choose walls

Apply

Properties

Action: Create

Dimension: 2D

Type: Shell

Property Set Name: outside_wall

Input Properties...


Thickness: 0.05

OK

Select Members: Surface 1:3 5 6 8 9 11 12 14:16

Add

Apply

Property Set Name: inner_walls

Input Properties


Thickness: 0.1

OK

Select Members Surface 4:13:3


For the flow tube elements, the equivalent hydraulic diameter is

\

9. Apply a heat load on the top surface.

Add

Apply

Properties

Action: Create

Dimension: 1D

Type: Flow Tube

Property Set Name: air_flow

Input Properties...

Material Name: m:air

Diameter at Node 1: 0.5333

OK

Select Members: Curve 5:9

Add

Apply

Load/BCs

Action: Create




New Set Name: flux


Input Data...

Surface Option: Top

Top Surf Heat Flux: 20

Dh 4 0.32⋅( ) 2.4( )⁄ 0.5333in= =



WORKSHOP 5

10. Define the Inlet Temperature of the Fluid.

11. Apply Coupled Advection. Five load sets, one for each channel, aredefined for the fluid-structure coupling.

OK



Select Surfaces or Edges: Surface 2 6:15:3

Add

OK

Apply

Load/BCs

Action: Create


Type: Nodal


Input Data...


OK



Select Geometry Entities Point 9 27:33:2

Add

OK

Apply

Load/BCs

Action: Create


Object: Convection


Option: Coupled Advection

New Set Name: conv1


Region 2: 1D

Input Data...

Surface Option: Top

Top Surf Heat Convection Coef:

0.3

Mass Flow Rate: 8.33e-3

OK



Change the view to Front View

Select Surfaces or Edges: Surface 1:4

Add

OK

Apply

Active list For the Companion Region


Add

OK

Apply



WORKSHOP 5

Do the same for the remaining four(4) channels.

New Set Name: conv2



Active list

Select Surfaces or edges: Surface 4:7

Add



Add

OK

Apply

New Set Name conv3





Add



Add

OK

Apply


New Set Name conv4





Add



Add

OK

Apply

New Set Name conv5





Add



Add

OK

Apply



WORKSHOP 5

12. Analyze the model.


Analysis

Action: Analyze



Job Name: ex5

Apply









WORKSHOP 5




Analysis

Action: Attach XDB


Method: Local



OK

Apply

Results

Form Type: Basic

Select Results Cases 1.1 Default, PW Linear: 100. % of Load

Select Fringe Result 1.1 Temperatures

Change to Iso 1 View

Apply



File/Quit...


Radiation Enclosures

WORKSHOP 6

Objective:


� Attain a temperature solution withing MSC.Nastran




WORKSHOP 6

Model Description:In this example we will model three plates that are in radiative equilibrium with a zero-degree ambient environment. Each plate measures 2 m by 3 m, and are arranged as shown in the figure below. The center plate (II) has a heat flux applied to it with a magnitude of 2000 W/m2 in the central region, as illustrated.

The emissivity of all surfaces is chosen as 1.0, representing perfect blackbodies. The plate thicknesses are all 0.001 m, and the material is aluminum. Temperature distribution for each plate will be determined.

I II III

1 m

1 1/2 m

2 m

2 m 3 m

3 m

q=2000 W/m2

Z

Y

X

k = 204 W/m-oK

Aluminum Plate

Thickness = 0.001 m

ε = 1.0

Cavity 1 Cavity 2




WORKSHOP 6


� Create a new database called radiation_enclosures.db

� Create surfaces that represents three plates.

� Each plate is meshed with sixteen QUAD8 elements

� Input specify Material Properties for the plates.

� Define the element properties using alum as the property name.

� Apply loads and boundary conditions to the model. Two radiation cavities are defined. Cavity 1 includes all the elements on Plates I and II that view each other. These elements also communicate with zero-degree space. The second cavity is comprised of the elements on Plates II and III, which see each other, and they also communicate with zero-degree space.

� The non-cavity sides of Plates I and III are treated as adiabatic surfaces (i.e., perfectly insulated

� The normal heat flux is applied to one side of the centermost four elements of Plate II, for a total heat load of 3000 W.

� Perform, read, and display the results.




WORKSHOP 6

Exercise Procedure:

1. Create a New Database called it radiation_enclosures.db


3. Create the surface representing a plate.

You will now use Transformation to create the other 2 surfacesparallel with the previous one.

File/New...

New Database Name radiation_enclosures

OK


Tolerance Default



OK

Geometry

Action: Create

Object: Surface

Method: XYZ



Apply

Geometry

Action: Transform

Object: Surface

Method: Translate



4. Mesh the plate



Apply

Change the view to Iso 2 View



Apply

Finite Elements

Action: Create

Object: Mesh Seed

Type: Uniform

�Number of Elements

Number=: 4



WORKSHOP 6

5. Mesh the solids to create Quad8 element with global edge length 1.0.

6. Create the isotropic material properties using the material constantsspecify in figure.

Curve List: Surface 1.1 1.2 2.1 2.2 3.1 3.2

Apply

Finite Elements

Action: Create

Object: Mesh

Type: Surface

Global Edge Length: 1

Element Topology: Quad8

�IsoMesh


Apply

Materials



8. Define the radiation enclosures by defining two cavities forradiation exchange. This will save a lot of time attaining atemperature solution within MSC ⁄NASTRAN. Basically, to identifythe TOP and BOTTOM surfaces appropriately, each independent

Action: Create

Object: Isotropic


Material Name: alum

Input Properties...


Thermal Conductivity: 204

OK

Apply

Properties

Action: Create

Dimension: 2D

Type: Shell

Property Set Name: alum

Input Properties...


Thickness: 0.001

OK

Select Members: Surface 1:3

Add

Apply



WORKSHOP 6

surface within an enclosure will have a distinct SET NAME.Consistent use of the ENCLOSURE ID with each SET NAMEensures that the elements are included in the appropriate enclosure.

Load/BCs

Action: Create

Object: Radiation


Options: Enclosures

New Set Name: enl_1


Input Data...

Surface Option: Top

Enclosure ID: 1

Top Surf Emissivity: 1.0

Surface Can Shade

Surface Can Be Shaded

OK



Select Surfaces or Edges: Surface 1

Add

OK

Apply

New Set Name: encl_1a

Input Data...

Surface Option: Bottom

Enlosure ID: 1

Bottom Surf Emissivity: 1.0


OK




Add

OK

Apply

New Set Name: encl_2

Input Data...

Surface Option: Top

Enlosure ID: 2


OK




Add

OK

Apply

New Set Name: encl_2a

Input Data...


Enlosure ID: 2

Bottom Surf Emissivity: 1.0

OK




WORKSHOP 6

9. Apply a Heat Flux on the Top Surfaces of the chip.



Add

OK

Apply

Load/BCs

Action: Create






Input Data...

Surface Option: Top

Top Surface Heat Flux 2000

OK


Geometry Filter: FEM

Select 2D Elements or Edges Elm 22 23 26 27

Add

OK

Apply


10. Perform the analysis.Since radiation heat transfer, by definitionmakes our problem highly nonlinear, we need to consider theDefault Initial Temperature setting if we hope to achieve aconverged solution with the MSC.Nastran thermal solver


Analysis

Action: Analyze



Job Name: ex6

Solution Type....

Solution Parameters....

Default Init Temperature=: 500

Radiation Parameters....

Stefan-Boltzmann Constant: 5.6696e-8

OK

OK

OK

Apply



WORKSHOP 6





When the run is completed, edit the ex6.f06 file and search for theword FATAL. If no matches exist, search for the word WARNING.Determine whether existing WARNING messages indicatemodeling errors.





Analysis

Action: Attach XDB


Method: Local



OK

Apply

Results

Object: Quick Plot

Select Results Cases: Default, A1:Non-Lin-ear: 100. % of Load

Select Fringe Result: Temperatures

Apply



WORKSHOP 6



File/Quit...



Axisymmetric Flow in a Pipe

WORKSHOP 7




WORKSHOP 7

Model Description:In this example we will analyze an axisymmetric structure for itstemperature distribution. We will use the MSC.NASTRAN CTRIAX6axisymmetric element (in its 3 node configuration) as the heat conductionelement.

The basic geometry is detailed in the figure above. A section of pipeconsisting of composite materials is divided into two different materialregions. Region A is from radius 1.5 feet to 3.5 feet. Region B is fromradius 3.5 feet to 4.75 feet. The overall pipe section is 5.0 feet long withan inside diameter of 3 feet and an outside diameter of 9.5 feet.

Oil flows through the interior with an inlet temperature of 100 oF and amass flow rate of 2.88E6 lbm/hr. The forced convection heat transfercoefficient between the oil and wall is calculated by MSC.NASTRANusing the following relationship:

Nu = 0.023 Re0.8 Pr0.3333. Thermal conductivity properties for Region Aand Region B are 0.2 and 0.5 Btu/hr-ft-oF. Volumetric internal heatgeneration occurs in the subregion of Region B (Specifically from radius3.5 feet to 3.9167 feet), and varies based on Z location. The heatgeneration is 1200 * (1-Z/5) Btu/hr-ft3, where Z is given in units of feet.Free convection to an ambient temperature of 100 oF is applied to theexterior surface of the structure through a heat transfer coefficient of 3.0Btu/hr-ft2-oF.

Figure 7.1

5.0 ft

KA = 0.2 Btu/hr-ft-oF

KB = 0.5 Btu/hr-ft-oF

Region A

1.5 ft

q = qvol (z) = 1200 (1 - Z/5) Btu/hr-ft3

3.5 ft3.9167 ft4.75 ft

Region BFluid

Tamb = 100 oF

h = 3.0 Btu/hr-ft2-oF

Oil Flow

X

Z

m = .

2.88E6 lbm/hr

Tin = 100 oF

µoil = 100.08 lbm/ft-hr

Cp oil = 0.44 Btu/lbm-oF

Koil = 0.077 Btu/hr-ft-oF

ρoil = 56.8 lbm/ft3

Nu = 0.023 Re0.8 Pr0.3333




WORKSHOP 7


� Create a new database called ex7.db

� Using thermal analysis, create a geometry representing a pipe divided up into two region.

� Perform meshing on the Fluid Curve and Pipe Surfaces using one way bias mesh seed.

� Mesh the rest of the solid.

� Merge all coincident nodes using Equivalence action in patran.

� Define all material properties accordingly.

� Using 2D Axisym Solid to define the element’s properties and 1D solid to represent the Flow Tube.




WORKSHOP 7

Exercise Procedure:

1. Open a new database. Name it ex7.db

The viewport (PATRAN’s graphics window) will appear along witha New Model Preference form. The New Model Preference sets allthe code specific forms and options inside MSC.PATRAN.


2. Create the Geometry.

Click on the Bottom View icon for working with axisymmetricgeometries.

File/New...

New Database Name: ex7

OK




OK

� Geometry

Action: Create

Object: Curve

Method: XYZ



Apply

� Geometry

Bottom View



Action: Create

Object: Surface

Method: XYZ

Surface ID List: 1



Apply

Surface ID List: 2

Vector Coordinates List: <.4167 0 5>


Apply

Surface ID List: 3

Vector Coordinates List: <.8333 0 5>


Apply



WORKSHOP 7

3. Mesh the Fluid Curve and Pipe Surfaces.

� Finite Elements

Action: Create

Object: Mesh Seed

Type: One Way Bias

Number: 10

L2/L1: 2.0

Curve List: Curve 1 Surface 1.4 3.2

Apply

� Finite Elements

Action: Create

Object: Mesh

Type: Surface


Element Topology: Tria3


Apply

� Finite Elements

Action: Create

Object: Mesh

Type: Curve


Element Topology: Bar2

Curve List: Curve 1

Apply


4. Remove Coincident Nodes.



� Finite Elements

Action: Equivalence

Object: All


Equivalencing Tolerance: 0.005

Apply

� Materials

Action: Create

Object: Isotropic


Material Name: mat_a

Input Properties...

Constitutive Model: Solid Properties




WORKSHOP 7

6. Define Element Properties.

Apply

Cancel

Material Name: mat_b

Input Properties...

Constitutive Model: Solid Properties


Apply

Cancel

Material Name: oil

Input Properties...

Constitutive Model: Fluid Properties


Specific Heat: 0.44

Density: 56.8

Dynamic Viscosity: 100.08

Apply

Cancel

� Properties

Action: Create

Object: 2D

Type: Axisym Solid

Property Set Name: pipe_a

Input Properties...

Material Name: m:mat_a

OK


Select Members: Surface 1

Add

Apply

� Properties

Action: Create

Object: 2D

Type: Axisym Solid

Property Set Name: pipe_b

Input Properties...

Material Name: m:mat_b

OK

Select Members: Surface 2 3

Add

Apply

� Properties

Action: Create

Object: 1D

Type: Flow Tube

Property Set Name: oil

Input Properties...

Material Name: m:oil

Hydraulic Diam. at Node: 3.0

OK

Select Members: Curve 1

Add

Apply



WORKSHOP 7

7. Define a Spatial Field.

8. Apply a Volumetric Heat Load.

� Fields

Action: Create

Object: Spatial

Method: PCL Function

Field Name: qvol_z

Scalar Function: 1200*(1.0-’Z/5.0)

Apply

� Load/BCs

Action: Create



Option: Volumetric Generation

New Set Name: qvol


Input Data...

Volumetric Heat Generation: f:qvol_z

OK



Select Surfaces: Surface 2

Add

OK

Apply



9. Apply Free Convection.

� Load/BCs

Action: Create

Object: Convection


Option: To Ambient

New Set Name: conv


Input Data...

Surface Option: edge

Edge Convection Coef: 3.0


OK





WORKSHOP 7

Click on the Edge View icon.

10. Define Inlet Temperatures of the Fluid.

11. Define Coupled Flow Tube.

Apply a fluid-structure coupling between the oil and inner wall ofthe pipe.

Select Surfaces: Surface 3.2

Add

OK

Apply

� Load/BCs

Action: Create


Type: Nodal


Input Data...


OK




Add

OK

Apply

� Load/BCs

Action: Create

Edge


Click on the Edge View icon.

Object: Convection


Option: Coupled Flow Tube

New Set Name: coup_ftube


Region 2: 2D

Input Data...

Form Type: Advanced

Mass Flow Rate: 2.88e6

Heat Transfer Coefficient: 0.023

Formula Type Option: � h=k/d*coef*Re**Expr*Pr**

Reynolds Exponent: 0.8

Prandtl Exponent, Heat In: 0.3333

OK




Add

Active List

Select Surfaces or Edges: Surface 1.4

Add

OK

Apply

Edge



WORKSHOP 7




� Analysis

Action: Analyze



Job Name: ex7

Apply




WORKSHOP 7










� Analysis

Action: Attach XDB


Method: Local



OK

Apply

� Results



Apply


Temperatures



WORKSHOP 7


The maximum temperature occurs near the internal heat generationregion with a temperature of 842.3oF. The fluid temperature remainsconstant at 100 oF because of the massive flow rate at 2.88E6 lbm/hr.

We can check the energy balance on this model as follows:

Total heat = 2.91246E4 Btu/hr (from the OLOAD RESULTANT ofthe F06 file)

Sum of the heat on the column under Free Convection = 2.5828E4Btu/hr

Sum of the heat on the column under Forced Convection = 3.297E3Btu/hr

Sum of the heat on the above two columns = 2.9125E4 Btu/hr, whichis equal to the input heat of 2.91246E4 Btu/hr.

An assumption of a 1-D fluid element is that temperature gradientswithin the fluid are only significant along the axial direction. Withsuch a large diameter flow tube, this assumption is probably beingmisused in this particular problem. The application of the flow tubeboundary convection relationship also implies fully developed flow,yet, over only a 5 foot section and with a 3 foot diameter, this is alsoa very crude approximation. In essence, what we are saying, is thatthis example serves to illustrate coupled convection in anaxisymmetric environment, application of spatial heat loads, and useof convection correlation equations, rather than fluid physics.


Quit MSC.Patran when you have completed this exercise.


Directional Heat Loads

WORKSHOP 8




WORKSHOP 8

Model Description:In this example we will apply a directional heat load on cylinder. Wewill orient the surface normal from the surface such that the normalvector (Right hand rule) will point away from the surface. Thisallows the incoming directional heat flux to see the normals, andproject the correct energy by forming a dot product with this vector.A typical application of this directional heat load process is in anorbital heating environment.

The dimension of the cylinder is 1.5 inch in diameter with a lengthof 6 inches. The material is aluminum with a thermal conductivity of3.96 W/in-oC. The absorptivity and emissivity of the cylindersurface are 0.8. The directional heat load is 30 W/in2. The exteriorsurface of the cylinder looses heat by radiation to space. Theradiation view factor is 1.0 and the ambient temperature is 20 oC.

Figure 8.1

6.0 in

q = qvec = 30 Tamb = 20.0 oCView Factor = 1.0

1.5 in

k = 3.96 W/in-oC

Aluminum Cylinder

α = ε = 0.8

Thickness = 0.0625 in

Radiation Boundary Condition

X

Y

Z




WORKSHOP 8


� Create a new database called

� Create the Surfaces of Printed Circuit Board and Electric Components.

� Extrude the Surfaces to Create Solids.

� Mesh the Solids.

� Specify Materials.

� Define Element Properties.

� Merge the Common Nodes.

� Verify the Free Edges.

� Apply a heat load on each device.

� Apply a convection boundary condition on the PCB.

� Perform the Analysis.

� Read the analysis results.

� Display the results.




WORKSHOP 8

Exercise Procedure:




2. Create the geometry.

File/New...


OK




OK

� Geometry

Action: Create

Object: Point

Method: XYZ

Point ID List: 1

Refer. Coordinate Frame: Coord 0

Point Coordinates List: [0.75 0 0]

Apply

� Geometry

Action: Create

Object: Curve

Method: Revolve


Click on the Iso 1 View icon to obtain a 3D view of the cylinder.


Curve ID List: 1

Total Angle: 360.0

Auto Execute

Point List: Point 1

Apply

� Geometry

Action: Create

Object: Surface

Method: Extrude

Translation Vector: <0 0 -6>

Curve List: Curve 1

Apply

Iso 1 View



WORKSHOP 8

The surface normal direction is important in this problem, becausethe incoming heat flux vector will form a dot product with thenormal vector for the surface generating the correct projectedsurface area for application of the heat load. Therefore, when wecreated the cylinder using geometry, we should verify that thenormal vector points outward. This is accomplished by using:

Click on the Front View icon.

Select Surface 1 to make sure that the normal vector indicated by thered arrow points outward from the cylinder. If the normal vector ispointing inward, then you can reverse the surface normal by usingthe following command:

� Geometry

Action: Show

Object: Surface

Method: Normal

Auto Execute


Apply

� Geometry

Action: Edit

Object: Surface

Method: Reverse

Auto Execute


Apply

Front View


3. Create Finite Elements.

Click on the Iso 1 View icon.


� Finite Elements

Action: Create

Object: Mesh

Type: Surface


Element Topology: Quad4


Apply

� Finite Elements

Action: Equivalence

Object: All



Apply

Iso 1 View



WORKSHOP 8




� Materials

Action: Create

Object: Isotropic


Material Name: alum

Input Properties...



Apply

Cancel

� Properties

Action: Create

Object: 2D


7. Apply a Directional Heat Load.

Type: Shell

Property Set Name: alum

Input Properties...


Thickness: 0.0625

OK


Add

Apply

� Load/BCs

Action: Create


Option: DirectionalFluxes

Type: ElementUniform

New Set Name: vector_flux


Input Data...

Surface Option: Top

Top Surf Absorptivity: 0.8

Top Surf Heat Flux: 30

Incident Thermal Vector: <-1 0 0>

OK



Select Surface or Edges: Surface 1

Add



WORKSHOP 8

8. Apply a Radiation Boundary Condition.

OK

Apply

� Load/BCs

Action: Create

Object: Radiation

Type: ElementUniform

Option: Ambient Space

New Set Name: rad_space


Input Data...

Surface Option: Top


Top Surf Absorptivity: 0.8


View Factor: 1.0

OK



Select Surface or Edges: Surface 1

Add

OK

Apply



9. Specify Radiation Parameters and Perform the Analysis.

� Analysis

Action: Analyze



Job Name: ex8

Solution Type...

� STEADY STATE ANALYSIS


Radiation Parameters...

Absolute Temperature Scale: 273.15 Degree Celsius

Stefan-Boltzmann Constant: 3.6580e-11 WATTS/IN2/K4

OK

OK

OK

Apply



WORKSHOP 8










WORKSHOP 8




Analysis

Action: Attach XDB


Method: Local

Select Results File


OK

Apply

� Results



Apply


Temperatures



Example 8 demonstrates an aluminum cylinder in radiativeequilibrium. The heat source is directional (light source oriented),and the radiation boundary condition is equal for all directions. Thecylinder’s maximum temperature (~473 oC) is attained on the sidesubject to the solar heat load. The minimum temperature (~424 oC)occurs in the shadow region. The high conductivity of the cylinderhelps to equilibrate the temperatures. If the conductivity were verylow, the maximum temperature would approach 740 oC with theminimum approximately 20 oC.

Quit MSC.Patran when you have completed this exercise.


Thermal Stress Analysis from Directional Heat Loads

WORKSHOP 9


Thermal Stress Analysis from Directional HeatLoads


WORKSHOP 9

Model Description:This example demonstrates how to apply the thermal results ofExample 8 to perform a stress analysis. We will create thetemperature loading for the stress run by using the Create-Spatial-FEM command under the Fields Application. You can also use theinclude punch file option to get the thermal load.

The diameter of the cylinder is 1.5 inch with a length of 6 inches.The material is aluminum. The heat transfer problem solved inExample 8 resulted in a temperature solution which we would nowlike to apply to a thermal stress analysis.

Figure 9.1

6.0 in

Y

XZ

1.5 in

E = 1.0E7 lb/in2

Aluminum Cylinder

ν = 0.34

Thickness = 0.0625 in

α = 1.3E-5 in/in-oC




WORKSHOP 9


� Create a new database called ex9.

� Create Spacial FEM based on the Temperature Profile.

� Specify the material properties after changing the Analysis Type to Structural.

� Define element properties using 2D shell.

� Create new load case and applyed fixed boundary conditions on the end of the cylinder.

� Apply boundary conditions to the structural load case and define temperature load to the model.

� Analyze the model

� Read and display the results.




WORKSHOP 9

Exercise Procedure:

1. Open the database ex8.db from the previous exercise.

2. Create a Spatial FEM based on the Temperature Profile.

3. Change the Analysis Type to Structual.

4. Specify the Structural Materials.

File/Open...

Existing Database Name: ex8

OK

� Fields

Action: Create

Object: Spatial

Method: FEM

Field Name: tempload

FEM Field Definition: � Continuous

Field Type: � Scalar

Mesh/Results Group Filter: � Current Viewport

Select Group:

Apply

Preferences/Analysis...

Analysis Type: Structural

OK

� Materials

Action: Create

Object: Isotropic


default_group


5. Assign Element Properties.

When asked, “Surface 1 already has been associated to an elementproperty region. Overwrite the association?”, answer Yes.

6. Create a New Load Case.

Material Name: alum_st

Input Properties...

Constitutive Model: Linear Elastic

Elastic Modulus: 1.0e7

Poisson Ratio: 0.34

Thermal Expan. Coeff: 1.3e-5

Reference Temperature: 0.0

Apply

Cancel

� Properties

Action: Create

Object: 2D

Type: Shell

Property Set Name: alum_st

Input Properties...

Material Name: m:alum_st

Thickness: 0.0625

OK


Add

Apply

Yes



WORKSHOP 9

We will create a new load case consisting of the structural thermalloading and apply the fixed boundary conditions on the ends of thecylinder.

7. Apply the Clamped Boundary Conditions.

Click on the Curve or Edge icon.

� Load Cases

Action: Create

Load Case Name: struct_load

Load Case Type: Static

Apply

� Load/BCs

Action: Create

Object: Displacement

Type: Nodal


Current Load Case: struct_load

New Set Name: clamp_bc

Input Data...

Load/BC Set Scale Factor: 1.0

Translations <T1 T2 T3> < 0., 0., 0.>

Rotations <R1 R2 R3> < 0., 0., 0.>

OK



Select Geometry Entities: Curve 1 Surface1.3

Curve or Edge


8. Define a Temperature Load.


Add

OK

Apply

� Load/BCs

Action: Create

Object: Temperature

Type: Nodal



New Set Name: temp_load

Input Data...


Temperature: f:tempload

OK



Select Geometry Entities: Surface 1

Add

OK

Apply

Surface or Face



WORKSHOP 9




� Analysis

Action: Analyze



Job Name: ex9

Subcase Select...

Subcases For Solution Sequence:101

Subcases Selected:

OK

Apply

struct_load

Default









WORKSHOP 9




Analysis

Action: Attach XDB


Method: Local

Select Results File


OK

Apply

� Results



Result Position:

Result Quantity: von Mises

Select DeformationResult:

Apply

struct_load, Static Subcase

Stress Tensor

At Z1

Displacements, Translational



For output we plot the von Mises stress for the fixed end cylinderundergoing the directional thermal load. Peak stresses occur near thefixed end points (recall the points are fixed in X, Y, and Zdirections). Thermal expansion causes growth in the axial and radialdirections with a circumferential variation due to the directionalnature of the thermal load. Near the cylinder mid-plane, in an axialsense, we find the maximum stress at the location which is normalto the directional load vector. The minimum is on the opposite sideof the cylinder in the shadow.

Quit MSC.Patran when you have completed this exercise


Thermal Stress Analysis of a Bi-Metallic Plate

WORKSHOP 10




WORKSHOP 10

Model Description:In this example we will perform the thermal stress analysis of a bi-metallic strip. We will build the entire model from geometricconstruction so that we can apply loads directly on the geometry.The dimension of the bi-metallic strip is one inch by one inch. Thethickness for the solder type material is 0.05 inch, and the thicknessof the Ge material is 0.025 inch. Thus the assembly thickness is0.075 inch.

The top surface temperature boundary condition is -30o C, and thebottom surface temperature boundary condition is 70o C. We willdetermine the temperature distribution by running a steady-statethermal analysis.

Figure 10.1

Prior to the development of the MSC.Patran MSC.Nastran HeatTransfer interface, one would request:

TEMP(PUNCH)=all

in the MSC.Nastran Case Control section of the thermal run. Thetemperature load is then created and saved inside the punch file. Inthe subsequent thermal stress analysis one can access this file bydefining

TEMP(LOAD)=1

in the Case Control section of the ensuing stress analysis run.

T = 70.0 oC

KGe = 1.524 W/in-oC

Ksolder = 1.27 W/in-oC

X

Y

1.0 in

1.0 in

X

Ge: 0.025 in

Solder: 0.05 in

Z T = -30.0 oC

EGe = 1.885E7 lb/in2

GGe = 0.933E7 lb/in2

αGe = 5.8E-6 in/in-oC

ESolder = 1.3E7 lb/in2

νSolder = 0.4αSolder = 2.47E-5 in/in-oC

Tref = -30 oC


However, using MSC.Patran you can use the Create-Spatial-FEMcommand after you have postprocessed the thermal result in theviewport. We will use this technique to apply a thermal load for thestress analysis. Also, we will analyze the thermal stress analysis forthe free-free expansion by enforcing a minimum number ofconstraints to fix-rigid body motion.



WORKSHOP 10


� Create a new database called ex10.db

� Create a geometry representing a bi-metallic strip.

� Mesh the solid using Uniform Mesh Seed for solid 1 and Mesh using HEX8 for both solids.

� Merge all coincident nodes using Equivalence action in the Finite Elements menu

� Specify thermal material properties.

� Define properties using 3D solid for each individual parts.

� Apply temperature boundary conditions to the solid.

� Analyze, perform, and read the results.

� Define a spatial FEM Field based on the temperature Profile.

� Define the new material properties using structural analysis.

� Apply different loads and boundary conditions for the solid

� Perform the structural analysis and read the results.




WORKSHOP 10

Exercise Procedure:




2. Create the Model.

File/New...


OK




OK

� Geometry

Action: Create

Object: Surface

Method: XYZ



Apply

� Geometry

Action: Create

Object: Solid

Method: Extrude



Click on the Solid Face icon.


3. Mesh the Solids.

Auto Execute


Apply


Surface List: Solid 1.6

Apply

� Finite Elements

Action: Create

Object: Mesh Seed

Type: Uniform

Solid Face



WORKSHOP 10

Click on the four corners of Solid 1. Hold shift key down while youclick.

Click on the four corners of Solid 2. Hold shift key down while youclick.


Number: 4

Curve List: Solid 1.1.1 1.2.1 1.2.3 1.1.3

Apply

Number: 2

Curve List: Solid 2.1.1 2.2.1 2.2.3 2.1.3

Apply

� Finite Elements

Action: Create

Object: Mesh

Type: Solid


Element Topology:

Solid List: Solid 1 2

Apply

� Finite Elements

Action: Equivalence

Object: All



Apply

Hex8



5. Specify Thermal Material Properties.

� Materials

Action: Create

Object: Isotropic


Material Name: Ge

Input Properties...



Apply

Cancel

Material Name: Solder

Input Properties...



Apply



WORKSHOP 10


Click on the Bottom View icon.

7. Apply temperature boundary conditions.

Cancel

� Properties

Action: Create

Object: 3D

Type: Solid

Property Set Name: Ge

Input Properties...

Material Name: m:Ge

OK


Add

Apply

Property Set Name: Solder

Input Properties...

Material Name: m:Solder

OK


Add

Apply

� Load/BCs

Action: Create

Bottom View



Object: Temp(Thermal)

Type: Nodal


New Set Name: temp_bottom

Input Data...


OK



Select Geometry Entities: Surface 1

Add

OK

Apply

New Set Name: temp_top

Input Data...

Boundary Temperature: -30

OK



Select Geometry Entities: Solid 2.6

Add

OK

Apply

Surface or Face



WORKSHOP 10


8. Perform the Thermal Analysis.


� Analysis

Action: Analyze



Job Name: ex10

Apply




9a. To submit the MSC.Patran .bdf file, find an available UNIXshell window. At the command prompt enter nastranex10.bdf scr=yes. Monitor the run using the UNIX pscommand.





WORKSHOP 10




Click on the Iso 1 View icon to change the view.

Analysis

Action: Attach XDB


Method: Local

Select Results File


OK

Apply

� Results

Form Type:

Select ResultsCases:

Apply


Temperatures

Iso 1 View



14. Define a Spatial FEM Field based on the Temperature Profile.

15. Change the Analysis type to Structural.

� Fields

Action: Create

Object: Spatial

Method: FEM

Field Name: t_load

FEM Field Definition: � Continuous

Field Type: � Scalar

Mesh/Results Group Filter: � Current Viewport

Select Group:

Apply

Preferences/Analysis...


OK

default_group



WORKSHOP 10

16. Specify Structural Material Properties.

17. Assign Element Properties.

� Materials

Action: Create

Object: Isotropic


Material Name: Solder_st

Input Properties...



Poisson Ratio: 0.4


Reference Temperature: -30.0

Apply

Cancel

Material Name: Ge_st

Input Properties...



Shear Modulus: 0.933e7


Reference Temperature: -30.0

Apply

Cancel

� Properties

Action: Create

Object: 3D


When asked, “Solid 2 already has been associated to an elementproperty region. Overwrite the association?”, answer Yes.

When asked, “Solid 1 already has been associated to an elementproperty region. Overwrite the association?”, answer Yes.

18. Create a New Load Case.

Type: Solid

Property Set Name: Ge_st

Options: StandardFormulation

Input Properties...

Material Name: m:Ge_st

OK


Add

Apply

Yes

Property Set Name: Solder_st

Options: StandardFormulation

Input Properties...

Material Name: m:Solder_st

OK


Add

Apply

Yes

� Load Cases

Action: Create



WORKSHOP 10

19. Define a Temperature Load.

Click on the Solid icon.

20. Apply constraints on the four corner points of the top surface.

Load Case Name: struct_load

Load Case Type: Static

Apply

� Load/BCs

Action: Create

Object: Temperature

Type: Nodal



New Set Name: temp_load

Input Data...


Temperature: f:t_load

OK



Select Geometry Entities: Solid 1 2

Add

OK

Apply

� Load/BCs

Solid


Click on the Point icon.

Action: Create

Object: Displacement

Type: Nodal


New Set Name: fix_x

Input Data...


Translations <T1 T2 T3> <0., , >

OK



Select Geometry Entities: Point 9 10

Add

OK

Apply

New Set Name: fix_y

Input Data...


Translations <T1 T2 T3> < , 0., >

OK




Add

OK

Point



WORKSHOP 10


Apply

New Set Name: fix_z

Input Data...


Translations <T1 T2 T3> < , , 0.>

OK



Select Geometry Entities: Point 9:12

Add

OK

Apply


21. Perform the Structural Analysis.

� Analysis

Action: Analyze



Job Name: ex10_st

Subcase Select...

Subcases For Solution Sequence:101

Subcases Selected:

OK

Apply

struct_load

default



WORKSHOP 10



To submit the MSC.PATRAN .bdf file for analysis, find an availableUNIX shell window. At the command prompt enter: nastranex10_st.bdf scr=yes. Monitor the run using the UNIX ps command.

23. When the run is completed, edit the ex10_st.f06 file and search forthe word FATAL. If no matches exist, search for the wordWARNING. Determine whether existing WARNING messagesindicate modeling errors.

24. Read in the Analysis Results.


� Analysis

Action: Read Output2


Method: Translate

Job Name: ex10_st


OK

Apply

� Results



Result Quantity: von Mises

Select DeformationResult:

Apply

ex10_st.op2

struct_load, Static Subcase

Stress Tensor

Displacements, Translational



The reference or zero stress state for the assembly is initialized at -30 oC. The thermal coefficient of expansion for the solder isapproximately four times that of Ge. When the temperature gradientassociated with the temperature boundary conditions is applied, thesolder layer wants to grow significantly more than the Ge layer duenot only to the higher coefficient of thermal expansion, but alsobecause of the higher temperature relative to TREF. The Ge layerends up with a more complex stress pattern due to its four cornerpoints being constrained, the distribution of temperature through thelayer, and the growth enforced by the solder layer. The free surfaceof the solder layer exhibits the low stress levels.

Quit MSC.Patran when you have completed this exercise

MSC.Nastran 104 Exercise Workbook A-1

Transient Thermal Analysis of a Cooling fin

APPENDIX A

Objectives:

� Create a new database.

� Create the surface.

� Assign the thermal loads

� Submit the model for analysis

A-2 MSC.Nastran 104 Exercise Workbook

Transient Thermal Analysis of a Cooling Fin


APPENDIX A


� Create a new database and name it fin.db.

� Create a surface model of the cooling fin

� Generate the finite elements using mesh seeds

� Define material and element properties.

� Apply the convection conditions to the model.

� Submit the model to MSC.Nastran for analysis.

� Review results.




APPENDIX A

Exercise Procedure:

1. Open a new database called fin.db.

In the New Model Preferences form set the following:


2. Create the surfaces of the cooling fin

Repeat the previous step to create the remaining surface.

File/New...

New Database Name fin

OK


Tolerance Default



OK

Geometry

Action: Create

Object: Surface

Method: XYZ

Reference Coordinate Frame Coord 0

Vector Coordinates List [0.5, 2, 0]

Origin Coordinates List [0, 0, 0]

Apply

Vector Coordinates List [0.5, 0.666667, 0]

Origin Coordinates List [0.5, 0.666667, 0]

Apply


3. Generate the mesh seed for the surfaces created:

Using the mesh seed generated in the previous step, mesh thegeometry and create finite elements.

Use equivalence function to make sure all the overlapping nodes areconnected.

Finite Element

Action: Create

Object: Mesh Seed

Method: Uniform

Element Edge Length Data Number of Elements

Number = 9

Curve List Surface 1.1 1.3

Apply

Number = 4

Curve List Surface 1.2 1.4 2.2 2.4

Apply

Number = 3

Curve List Surface 2.3

Apply

Finite Element

Action: Create

Object: Mesh

Method: Surface

Surface List Surface 1 2

Apply

Finite Element

Action: Equivalence

Object: All



APPENDIX A

4. Next, define a material using the specified thermal conductivity,specific heat, and density.


Apply

Materials

Action: Create

Object: Isotropic


Material Name: mat_1

Input Properties

Thermal Conductivity 6e-4

Specific Heat 0.146

Density 0.283

OK

Apply


5. Next, reference the material that was created in the previous step.Define the properties of the cooling fin.

6. Since this is a transient analysis problem, a transient load case needsto be defined before loads and boundary conditions are applied.

7. Assign the convection properties to the cooling fin.

7a. The convection on the left edge is defined as follows:

Properties

Action: Create

Object: 2D

Type: Shell

Property Set Name fin

Input Properties

Material Name m:mat_1

Thickness 1

OK

Select Members Surface 1 2

Add

Apply

Load Cases

Action: Create

Load Case Name transient

Load Case Type: Time Dependent

Apply

Loads/BCs

Action: Create

Object: Convection


New Set Name conv



APPENDIX A

7b. The right hand side of the fin undergoes a different type ofconvection.


Input Data


Edge Convection Coef 0.001543

Ambient Temperature 2500

OK


Geometry Filter Geometry

Select Surfaces or Edges Surface 1.1

Add

OK

Apply

Loads/BCs

Action: Create

Object: Convection


New Set Name conv_right


Input Data


Edge Convection Coef 0.001157


OK


Geometry Filter FEM


8. Click on the Analysis radio button on the Top Menu Bar andcomplete the entries as shown here:

Select 2D Elements or Edge Element 37:40.1.1 4:12:4.1.2 28:48:4.1.2 45:48.1.3

Add

OK

Apply

Analysis

Action: Analyze


Type: Analysis Deck

Translation Parameters

Data Output: XDB and Print

OK

Solution Type

Solution Type TRANSIENT ANALYSIS

Solution Parameters


OK

Subcase Create

Available Subcases transient

Subcase Parameter

Initial Time Step = 0.1

Number of Time Steps = 20

OK

Apply

Cancel

Apply



APPENDIX A





9a. To submit the MSC.Patran .bdf file, find an available UNIXshell window. At the command prompt enter nastran fin.bdfscr=yes. Monitor the run using the UNIX ps command.

9b. To submit the MSC.Nastran .dat file, find an available UNIXshell window and at the command prompt enter nastran finscr=yes. Monitor the run using the UNIX ps command.

10. When the run is completed, edit the fin.f06 file and search for theword FATAL. If no matches exist, search for the word WARNING.Determine whether existing WARNING messages indicatemodeling errors.



APPENDIX A


12. Proceed with the Reverse Translation process, that is, attaching thefin.xdb results file into MSC.Patran. To do this, return to theAnalysis form and proceed as follows:

13. When the translation is complete and the Heartbeat turns green,bring up the Results form.

Choose the Default result case, and plot the result by selectingTemperature in the Select Fringe Result.

Analysis

Action: Attach XDB


Method: Local

Select Results File

Select Results File fin.xdb

OK

Apply

Results

Action: Create

Object: Quick Plot

Select Result Cases Default, A1:Time = 1.02

Select Fringe Result Temperature

Apply


MSC.Nastran 104 Exercise Workbook B-1

Analytical Solution for a Simple Radiation to Space Problem

APPENDIX B

Objectives:

� Create a new database.

� Create the solid model

� Assign the thermal loads

� Submit the model for analysis

B-2 MSC.Nastran 104 Exercise Workbook

Analytical Solution for a Simple Radiation to SpaceProblem


APPENDIX B


� Create a new database and name it furnance.db.

� Create a surface of the wall and then extrude it to generate a solid model.

� Generate mesh seeds on the edges of the solid.

� Create a finite element model using the available mesh seeds.


� Apply the convection conditions to front surface of the furnance wall.

� Apply radiation and heat flux to the back side of the model.


� Review results.




APPENDIX B

Exercise Procedure:

1. Open a new database called furnance.db.

In the New Model Preferences form set the following:.

Change to a front view by selecting the Iso1 View button on thetoolbar.


2. Create the surfaces of the furnance wall.

File/New...

New Database Name furnance

OK


Tolerance Default



OK

Geometry

Action: Create

Object: Surface

Method: XYZ


Vector Coordinates List <3, 2.5, 0>

Origin Coordinates List [0, 0, 0]

Apply

Iso1 View


Extrude the surface to create a solid wall with thickness of 0.15

3. Create a finite element model

Generate two mesh seeds on the edge of the wall.:

Choose the lower right hand curve

Create mesh seed on the two longer edges of the solid

Geometry

Action: Create

Object: Solid

Method: Extrude


Translation Vector <0, 0, 0.15>

Surface List [Surface 1

Apply

Finite Element

Action: Create

Object: Mesh Seed

Method: Uniform

Element Edge Length Data Number of Elements

Number = 2

Curve List Solid 1.2.1

Apply

Element Edge Length Data Element Length (L)

Number = 0.2

Curve List Solid 1.4.3 1.1.2

Apply



APPENDIX B

Create finite elements using the mesh seeds generated in theprevious steps.

4. Define a material using the specified thermal conductivity.

5. Apply the material properties to the furnance wall

Finite Element

Action: Create

Object: Mesh

Method: Solid

Surface List Solid 1

Apply

Materials

Action: Create

Object: Isotropic


Material Name mat

Input Properties

Thermal Conductivity = 1.2

OK

Apply

Properties

Action: Create

Object: 3D

Type: Solid

Property Set Name solid

Input Properties

Material Name mat

OK


6. Assign the thermal loads to the wall

The front surfaces of the solid is undergoing convection.

Choose the front faces of solid

Heat flux and radiation is being applied to the back surface.

Select Members Solid 1

Add

Apply

Loads/BCs

Action: Create

Object: Convection


New Set Name convection


Input Data

Convection Coef 20


OK



Select Surfaces or Edges Surface 1.6

Add

OK

Apply

Loads/BCs

Action: Create





APPENDIX B

Specify the parameters for the radiation on the back surface.

New Set Name heat_flux


Input Data

Form Type: Basic


Bottom Surf Heat Flux 2020

OK



Select Solid Faces Solid 1.5

Add

OK

Apply

Loads/BCs

Action: Create

Object: Radiation


New Set Name radiation


Input Data

Top Surf Emissivity 0.8

Top Surf Absorptivity 0.8


View Factor 1

OK




An MSC.Nastran input file called furnance.bdf will be generated.This process of translating your model into an input file is called theForward Translation. The Forward Translation is complete when theHeartbeat turns green.


Select Solid Faces Solid 1.6

Add

OK

Apply

Analysis

Action: Analyze


Type: Analysis Deck



OK

Solution Type

Solution Type: STEADY STATE ANALY-SIS

Solution Parameters


Radiation Parameters

Stefan-Boltzmann Constant: 5.67e-8

OK

OK

OK

Apply



APPENDIX B



8a. To submit the MSC.Patran .bdf file, find an available UNIXshell window. At the command prompt enter nastranfurnance.bdf scr=yes. Monitor the run using the UNIX pscommand.

8b. To submit the MSC.Nastran .dat file, find an available UNIXshell window and at the command prompt enter nastranfurnance scr=yes. Monitor the run using the UNIX pscommand.

9. When the run is completed, edit the furnance.f06 file and search forthe word FATAL. If no matches exist, search for the wordWARNING. Determine whether existing WARNING messagesindicate modeling errors.



11. Proceed with the Reverse Translation process, that is, attaching thefurnance.xdb results file into MSC.Patran. To do this, return to theAnalysis form and proceed as follows:



Analysis

Action: Attach XDB


Method: Local

Select Results File

Select Results File furnance

OK

Apply

Results

Action: Create

Object: Quick Plot

Select Result Cases Default


Apply

MSC.Nastran 104 Exercise Workbook C-1

Printed Circuit Board Using 2 1/2 D Paved meshing method

APPENDIX C

Objective:


C-2 MSC.Nastran 104 Exercise Workbook

Printed Circuit Board Using 2 1/2 D PavedMeshing Method


APPENDIX C


� Create a new database called pcb.db




APPENDIX C

Exercise Procedure:

1. Create a New Database and name it pcb.db.



3. Create the surfaces representing the printed circucit board.

Repeat the previous step to create the two rectangular components.

File/New...

New Database Name pcb

OK


Tolerance Default



OK

Geometry

Action: Create

Object: Surface

Method: XYZ

Vector Coordinates List: <6.5 5.4 0>


Apply

Vector Coordinates List: <0.75 0.875 0>

Origin Coordinates List: [5 3.5 0]

Apply


Use the Curve object to create the two circular components

4. Create trimmed surfaces that will represent the components and thecircuit boards.

In order to create trimmed surfaces, the curves that represents theedges of the surface must be chained together.


Origin Coordinates List: [1 1.5 0]

Apply

Geometry

Action: Create

Object: Curve

Method: 2D Circle

Input Radius 0.75

Construction Plane List Coord 0.3

Center Point List [3.5 3 0]

Apply

Input Radius 0.5


Center Point List [4.5 1.5 0]

Apply

Input Radius 0.5


Center Point List [1.5 4 0]

Apply

Geometry

Action: Create

Object: Curve



APPENDIX C

Generate the trimmed surfaces using the chained curved created inthe previous steps.

Click NO when the message “Do you wish to delete the originalcurves?” appears. This also applies to the following steps.

Method: Chain

Delete Orginial Elements


Apply


Apply


Apply

Geometry

Action: Create

Object: Surface

Method: Trimmed

Option: Planar

Use All Edge Vertices

Delete Outer Loop

Outer Loop List Curve 4

Delete Inner Loops

Inner Loop List Curve 2 1 6 3 5

Apply

Geometry


Be sure to delete the curve lists in the Inner Loop List box

Action: Create

Object: Surface

Method: Trimmed

Option: Planar


Delete Outer Loop


Delete Inner Loops

Inner Loop List

Apply

Geometry

Action: Create

Object: Surface

Method: Trimmed

Option: Planar


Delete Outer Loop


Delete Inner Loops

Inner Loop List

Apply

Geometry



APPENDIX C


5. Create the finite element model

Action: Create

Object: Surface

Method: Trimmed

Option: Planar


Delete Outer Loop


Delete Inner Loops

Inner Loop List

Apply


Because the surfaces are trimmed and non-parametric surfaces,paver meshed is need to generate the finite elements.

Create the finite elements for the components.

Extrude the Quad4 elements to generate solid elements to representthe epoxy layer.

Finite Element

Action: Create

Object: Mesh

Method: Surface


Element Topology Quad4

Mesher Paver

Curve List Surface 4

Apply

Finite Element

Action: Create

Object: Mesh

Method: Surface


Element Topology Quad4

Mesher Paver

Curve List Surface 5 6 3 7 2

Apply

Finite Element

Action: Sweep

Object: Element

Method: Extrude

Direction Vector <0 0 0.010>



APPENDIX C

Repeat the previous step and create the solid elements on top of theepoxy elements to represent the components, and the circuit board.

Extrude Distance 0.010

Offset 0.0


Base Entity List Elm 3044:3657:1

Mesh Control

Number = 2

OK

Apply

Finite Element


Offset 0.010



Mesh Control

Number = 2

OK

Apply

Direction Vector <0 0 -0.2>


Offset 0.0



Apply


Equivalence the model to make sure all the intersecting nodes areconnected.

Use the Verify command to make sure that the model is meshedcorrectly.

Finite Element

Action: Equivalence

Object: All


Equivalencing Tolerance 0.0045

Apply

Finite Element

Action: Verify

Object: Element

Method: Boundaries

Display Type Free Edges

Apply



APPENDIX C

6. Create groups that represent the base component, chip, and epoxyfinite elements.

Group/Create...

Action: Create

New Group Name base_component

Make Current

Group Contents: Add Entity Selection

Entity Selection Elm 3044:3657:1

Apply

Group/Create...

Action: Create

New Group Name chip

Make Current


7. Post the Chip, default_group, and epoxy groups to show the finiteelements in the group.

8. Define the three different materials using the specified thermalconductivity.



Apply

Group/Create...

Action: Create

New Group Name epoxy

Make Current



Apply

Group/Post...

Action: Post

Select Group to Post Chipdefault_groupepoxy

Apply

Group/Post...

Action: Post

Select Group to Post default_group

Apply

Materials



APPENDIX C

Action: Create

Object: Isotropic


Material Name: component

Input Properties

Thermal Conductivity 0.89

OK

Apply

Materials

Action: Create

Object: Isotropic


Material Name: glue

Input Properties


OK

Apply

Materials

Action: Create

Object: Isotropic


Material Name: circuit_board

Input Properties



9. Apply the material properties to the finite elements.

OK

Apply

Properties

Action: Create

Object: 3D

Type: Solid

Property Set Name pcb

Input Properties

Material Name m:circuit_board

OK

Select Members Elm 6114:13427:1

Add

Apply

Properties

Action: Create

Object: 3D

Type: Solid

Property Set Name chip

Input Properties

Material Name m:component

OK


Add

Apply

Properties



APPENDIX C

10. Apply the heat flux to the top surfaces of the chips

Before you select the element faces, change the rectangular pickingpreference to Enclose Entire Entity.

Action: Create

Object: 3D

Type: Solid

Property Set Name epoxy

Input Properties

Material Name m:glue

OK


Add

Apply

Loads/BCs

Action: Create



New Set Name heatflux


Input Data

Form Type: Basic

Heat Flux 3

OK


Geometry Filter FEM

Preferences/Picking...


Also, in the FEM Select Menu, pick the Face of element icon.

Next, click on the Top View button on the main menu.

Now drag a rectangular box across the end of the chip elements asshonw in the following figure.

Rectangle/Polygon Picking Enclose entire entity

OK

Select 3D Element Faces Elm 4760:5372:1

Add

OK

Apply

Face of element

Top View



APPENDIX C

Set the boundary condition on the circuit board so it is permanetlykept at 40 degree.

Select the right and left edges of the circuit board.


Loads/BCs

Action: Create


Type: Nodal

New Set Name temp_edge

Input Data

Boundary Temperature 40

OK


Geometry Filter FEM

Select Nodes Node 2 67:120

Add

OK

Apply

Analysis

Action: Analyze


Type: Analysis Deck



OK

Solution Type


An MSC.Nastran input file called pcb.bdf will be generated. Thisprocess of translating your model into an input file is called theForward Translation. The Forward Translation is complete when theHeartbeat turns green.

Solution Type STATIC STATE ANAL-YSIS

Solution Parameters


OK

OK

Apply



APPENDIX C



12a. To submit the MSC.Patran .bdf file, find an available UNIXshell window. At the command prompt enter nastran pcb.bdfscr=yes. Monitor the run using the UNIX ps command.

12b. To submit the MSC.Nastran .dat file, find an available UNIXshell window and at the command prompt enter nastran pcbscr=yes. Monitor the run using the UNIX ps command.

13. When the run is completed, edit the pcb.f06 file and search for theword FATAL. If no matches exist, search for the word WARNING.Determine whether existing WARNING messages indicatemodeling errors.



15. Proceed with the Reverse Translation process, that is, attaching thepcb.xdb results file into MSC.Patran. To do this, return to theAnalysis form and proceed as follows:



Analysis

Action: Attach XDB


Method: Local

Select Results File

Select Results File pcb.xdb

OK

Apply

Results

Action: Create

Object: Quick Plot

Select Result Cases Default


Apply

MSC.Nastran 104 Exercise Workbook D-1

Create Group and List

APPENDIX D

Objectives:� Read in the Patran session file.

D-2 MSC.Nastran 104 Exercise Workbook



APPENDIX D


� Create a new database and name it pwb.db.

� Read in a session file called pwd1.ses

� Click on the Analysis toggle in the Main window: Analyze-Entire Model-Full run: Job name is pwb.

� When the job is completed, you can read in the XDB results. PATRAN version 9 now support XDB file by default.

� Attach XDB –Result entities-local: select the pwb.xdb.

� Click on the Results toggle, and create-quick plot-and select the temperature results.




APPENDIX D

Exercise Procedure:

1. Open a new database and name it pcb.db.



2. Read in the session file called pcb1.ses and play it.

3. Click on the Analysis radio button on the Top Menu Bar andcomplete the entries as shown here:.

File/New...

New Database Name pcb

OK


Tolerance Default



OK

File/Session/Play...

Play from file pcb1

Apply

Analysis

Action: Analysis


Method: Full Run

Job Name pwb

Apply





APPENDIX D



4a. To submit the MSC.Patran .bdf file, find an available UNIXshell window. At the command prompt enter nastran fin.bdfscr=yes. Monitor the run using the UNIX ps command.

4b. To submit the MSC.Nastran .dat file, find an available UNIXshell window and at the command prompt enter nastran finscr=yes. Monitor the run using the UNIX ps command.




7. Proceed with the Reverse Translation process, that is, attaching thefin.xdb results file into MSC.Patran. To do this, return to theAnalysis form and proceed as follows:



9. Create a group named new_85.

Analysis

Action: Attach XDB


Method: Local

Select Result File...

Select Result File pwb.xdb

OK

Apply

Results

Action: Create

Object: Quick Plot

Select Results Cases Default


Apply

Group/Create...

Action: Create

New Group Name new_85

Make Current

Apply



APPENDIX D

Tools/List/Create...

Model: FEM

Object: Element

Method: Attribute

Attribute Fringe Value

TOL-FRI 0.005

F 85

Target List “A”

Apply

List A

Add to Group

Existing Groups new_85

Group Name new_85

Apply

Group/Create...

Action: Create

New Group Name other_than_85

Make Current

Apply


Model: FEM

Object: Element

>


Method: Attribute

Attribute Material

Existing Materials Epoxy_glass_boardbondlinechip

Target List “B”

Apply

List A

Add to Group

Operation:

Add to Group

Existing Groups other_than_85

Group Name other_than_85

Apply

Group/Create...

Action: Create

New Group Name components

Make Current

Apply

Group/Create...

Action: Create

New Group Name thermal_grease

A B

B - A



APPENDIX D

Before you click the Apply button, you should click on the Clearbutton in the List A form. This is to make sure that List A does nothave any existing elements.

Once you have done that, then you click on the Apply on the CreateList menu, this will create the following elements on the List Aform.

Make Current

Apply

Group/Create...

Action: Create

New Group Name pcb

Make Current

Apply


Model: FEM

Object: Element

Method: Attribute

Attribute Material

Existing Materials chip

Target List “A”

Apply

List A

Add to Group

List Save

Existing Groups components


Group Name components

Apply

Display/Entity Color/Label/Render...

Target Group(s) components

Render Style: Shaded/Smooth

Apply

Display/Entity Color/Label/Render...

Target Group(s) pcb

Render Style: Shaded/Smooth

Apply

Group/Post...

Action: Post

Seelct Group to Post Componentspcb

Apply

MSC.Nastran 104 Exercise Workbook E-1

APPENDIX E

Importing IGES file and auto-tet mesh the model

Objectives:� Importing IGES geometry, and create a B-Rep solid from

all the surfaces� Auto-Tet mesh the model with TETRA10� Apply convection heating on the blade surfaces with h=10,

and hot ambient temperature at 1000 F� Apply a constant base temperature of 70 degree F� Obtain a temperature contour

E-2 MSC.Nastran 104 Exercise Workbook

APPENDIX E Importing IGES file and auto-tet mesh the model



� Create a new database and name it fin.db.

� Create a surface model of the cooling fin

� Generate the finite elements using mesh seeds


� Apply the convection conditions to the model.


� Review results.




Exercise Procedure:

1. Open a new database called fin.db.



2. Import the IGES geometry

Click OK when the IGES Import Summary appears

3. Create a B-Rep solid from all the surfaces

File/New...

New Database Name prob16

OK


Tolerance Default



OK

File/Import...

Source: IGES

Import File mblade.igs

Apply

Geometry

Action: Create

Object: Solid

Method: B-rep

Surface List Surface 1:34(Select all the surfaces)


Switch the viewport to ISO2 view by click on the ISO 2 View icon onthe Main Menu.

Also view the model in Smooth Shaded view.

4. Mesh the solid using TetMesh

Apply

Finite Element

Action: Create

Object: Mesh

Type: Solid

Mesher TetMesh

Element Topology Tet10

Input List Solid 1

Apply

Iso 2 View

Smooth Shaded



5. Next, define a material using the specified thermal conductivity.

6. Next, reference the material that was created in the previous step.Define the properties of the blade.

7. Apply the constant temperature boundary conditions at the base.

Materials

Action: Create

Object: Isotropic


Material Name: Titan

Input Properties


OK

Apply

Properties

Action: Create

Object: 3D

Type: Solid

Property Set Name solid

Input Properties

Material Name m:Titan

OK

Select Members Solid 1

Add

Apply

Loads/BCs

Action: Create



Now assign the Convection boundary conditions on the surfaces of theblade.

Type: Nodal

New Set Name base_temp

Input Data

Boundary Temperature 70

OK



Select Geometry Entities Surface 3 5

(Select the bottom 2 arcs)

Add

OK

Apply

Loads/BCs

Action: Create

Object: Convection


New Set Name convection


Input Data

Convection Coefficient 10


OK



Select Solid Faces Solid 1.22 1.21

(Click on the blade to select both faces)




Add

OK

Apply

Analysis

Action: Analyze


Type: Analysis Deck



OK

Solution Type

Solution Type STEADY STATE ANALYSIS

OK


An MSC/NASTRAN input file called prob16.bdf will be generated.This process of translating your model into an input file is called theForward Translation. The Forward Translation is complete when theHeartbeat turns green.

Apply




9. Submit the input file to MSC/NASTRAN for analysis.

9a. To submit the MSC/PATRAN .bdf file, find an availableUNIX shell window. At the command prompt enter nastranprob16.bdf scr=yes. Monitor the run using the UNIX pscommand.

9b. To submit the MSC/NASTRAN .dat file, find an availableUNIX shell window and at the command prompt enternastran prob16 scr=yes. Monitor the run using the UNIX pscommand.



11. MSC/NASTRAN Users have finished this exercise. MSC/PATRAN Users should proceed to the next step.

12. Proceed with the Reverse Translation process, that is, attaching theprob16.xdb results file into MSC/PATRAN. To do this, return to theAnalysis form and proceed as follows:



Analysis

Action: Attach XDB


Method: Local

Select Results File

Select Results File prob16.xdb

OK

Apply

Results

Action: Create

Object: Quick Plot

Select Result Cases Default, A1:Non-Linear:100.% Load

Select Fringe Result Temperatures

Apply




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