WORKSHOP 6 COMPARISON OF TWO HEAT SINK DESIGNS

WS6-2 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation

WS6-3 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Model Description In this exercise you will model a section of a finned heat sink in order to compare the effect of using different materials. The model is a representative fin section of a compressor cylinder casing. The maximum total heating on the casing interior has been determined. A choice of materials is open; the casing can be either aluminum or 1020 steel. Other than cost the only remaining discriminator is temperature; the interior casing surface must not exceed 212 F. If both materials keep this surface at or below 212 F steel will be used otherwise aluminum would be the material of choice. This analysis will determine the material choice.

WS6-4 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation

WS6-5 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Objectives Model two competing finned heat sinks. These will be 2D axisymmetric slices. Exercise Overview: 1. Create a new database named exercise_06.db. Set Tolerance to Default, and the Analysis Code to MSC/THERMAL. 2. Create the five surfaces which define the heat sink geometry. 3. Transform the geometry to create the second heat sink. 4. Mesh the surfaces with an IsoMesh. 5. Create an ambient node Equivalence the nodes at the mating surface edges. 7. Apply element properties to the elements using the MIDs provided. These are 2D Thermal Axisymmetric elements. 8. Apply temperature, flux and convection boundary conditions. 9. Prepare and submit the model for analysis specifying that it is an Axisymmetric Geometry model, that a units conversion is required, and that the direct solver will be used for analysis. 10. Read the results file and plot results. 11. Check the results against the requirement of 212 °F. 12. Quit MSC.Patran.

WS6-6 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 1: Open a new Database f b c e d Create a new database called exercise_06.db. a. File / New. b. Enter exercise_06 as the file name. c. Click OK. d. Choose Default Tolerance. e. Select MSC.Patran Thermal as the Analysis Code. f. Click OK. a

WS6-7 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 2: Create The Heat Sink Surfaces Create the five surfaces which define the model geometry for one of the heat sinks. a. Geometry: Create/ Surface/XYZ. b. Enter for Vector Coordinate List. c. Enter [2 0 0] for Origin Coordinates List. d. Click Apply. b c a d

WS6-8 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 2: Create The Heat Sink Surfaces (Cont.) Continue to create the five surfaces which define the model geometry. a. Geometry: Transform/Surface/ Translate b. Enter for Translation Vector. c. Deselect Auto Execute. d. Select Surface 1 for Surface List. e. Click Apply. f. Use Show Label icon to display labels. a b c d e f

WS6-9 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 2: Create The Heat Sink Surfaces (Cont.) Create the five surfaces which define the model geometry. a. Geometry: Transform/Surface/Translate. b. Enter for Translation Vector. c. Enter 3 for Repeat Count. d. Select Surface 2 for Surface List. e. Click Apply. b d a e c

WS6-10 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 3: Create the Second Heat Sink Surfaces Transform the geometry to create the geometry for the second heat sink model. a. Geometry: Transform/Surface/ Translate. b. Enter for Translation Vector. c. Enter 1 for Repeat Count. d. Drag a rectangle around all the surfaces for Surface List. e. Click Apply. a c b d e

WS6-11 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 4: IsoMesh The Surfaces Mesh the surfaces with IsoMesh. a. Select Finite Elements Applications button. b. Set the Action, Object, and Type to Create/Mesh/Surface. c. Set Global Edge Length to 0.1. d. Select all surfaces for inclusion in Surface List. e. Click Apply. f. Use Hide Label Icons to turn off all labels. The display should now appear as shown. b c d a e e d

WS6-12 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 5: Create An Ambient Node Create an ambient node 999. a. Elements: Create/Node/Edit. b. Enter 999 for Node ID List. c. Deselect Associate with Geometry. d. Enter [ ] for Node Location List. e. Click Apply. f. Display/Finite Elements… g. Adjust the node size to 6 using the slider bar. h. Click Apply, then Cancel. i. Un-display the node markers. f d a c b d e g h i Node 999

WS6-13 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 6: Equivalence Nodes Equivalence nodes at adjacent surface edges. a. Elements: Equivalence/All/ Tolerance Cube. b. Select Apply to connect elements at adjacent geometric edges. c. Display the node markers. b a b c

WS6-14 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 7: Create Element Properties Create element properties for the elements using the two material property MIDs, 1 and 353 a. Properties: Create/2D/Thermal Axisymmetric. b. Enter Property Set Name Steel. c. Click Input Properties… d. Click in the Material Name box and enter 353. e. Select OK to close the form. f. Click in the Select Members box. g. Drag a rectangle around the lower heat sink model surfaces, select Add, then Apply. h. Perform the same steps for the upper model using Aluminum for Property Set Name, and 1 for Material Name. b c f a d e Note: in a typical modeling sequence the materials application button would be the next step to define a material for application in element properties. However, MSC.Thermal includes a material properties database which contains 970 materials with thermal properties already defined. Use this database to facilitate the analysis. Lower heat sink model surfaces g g g h Upper heat sink model surfaces

WS6-15 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 8: Apply Boundary Conditions Apply the temperature, convection, and heat flux boundary conditions to the model. a. Loads/BCs: Create/Temperature/Nodal. b. Select Fixed for Option. c. Enter Ambient for New Set Name. d. Click Input Data… e. Enter 80.0 for Fixed Temperature. f. Click OK. g. Click Select Application Region… h. Select FEM for Geometry Filter. i. Select Node 999 for Select Nodes. j. Click Add and OK. k. Click Apply. e f h i j b c d g k Node 999 a

WS6-16 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 8: Apply Boundary Conditions (Cont.) Apply the temperature, convection, and heat flux boundary conditions to the model (continued). a. Loads/BCs: Create/Convection/Element Uniform. b. Select Template, Convection for Option. c. Enter Air for New Set Name. d. Select 2D for Target Element Type. e. Click Input Data… f. Enter 2.0 for Convection Coefficient. g. Select Node 999 for Fluid Node ID. h. Click OK. i. Click Select Application Region… j. Select Geometry for Geometry Filter. k. Select the Edge icon. l. Using shift-left mouse button select the edges as shown. Select edges for both upper and lower surfaces. m. Click Add and OK. n. Click Apply. k g f h j m l b c d e i n a l l

WS6-17 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 9: Apply Load Apply the flux boundary conditions to the model a. Change Action/Object/Type to Create/heating/Element Uniform. b. Set the Option to Flux,Fixed. c. Enter Flux as new set name d. Set the Target Element Type to be 2D. e. Click Input Data. f. Enter 3400 Btu/(hr*ft 2 ) for Fixed Heat Flux. g. Click OK h. Click Select Application Region… i. Select Geometry for filter j. Click Edge icon. k. Use shift-left mouse button to select the left vertical edges for both upper and lower surfaces. l. Click Add and OK. m. Click Apply. f j i k a b c d h m e l g k

WS6-18 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 10: Display all Loads/BCs Some of the loads and boundary conditions are already displayed. Display any additional ones. a.Change Action/Object/Type to Plot Markers. b.Under Assigned Load/BC Sets select all sets. c.Under Group Filter/Select Groups select default_group. d.Click Apply.

WS6-19 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 11: Prepare And Run Analysis Prepare and submit the model for analysis a. Analyze: Analyze/Full Model/Full Run. b. Click Translation parameters… c. Select Axisymmetric Geometry, R Z Co- ordinates for Model Dimensionality. d. Select X axis for Radial, R Co-ordinate. e. Select Y axis for Centerline, Z Co-ordinate. f. Click Perform Geometry Units Conversion. g. Select inches for From Units. h. Select feet for To Units. i. Select 3,mpidfph.bin (BTU- feet-lbm-hour… for File to Extract Undefined Materials. j. Click OK. k. Click Output Requests… l. Select Fahrenheit. m. Enter Hours for Units Definition for Time Label. n. Click OK. o. Continue to next page. a b c d e g f h i j k l m n

WS6-20 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 11: Prepare And Run Analysis (Cont.) Prepare and submit the model for analysis (continued). a. Click Solution Parameters… b. Select Fahrenheit. c. Select 2,Direct Solver for Solver Option. d. Click Run Control Parameters… e. Enter for Initial Temperature. f. Select Fahrenheit for Initial Temperature Scale. g. Click OK, OK and Apply. a b c e g g d f

WS6-21 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 12: Read And Plot Results Read results file and plot results. a. Select the Analysis application button. b. Set Action/Object to Read Result/Results Entities. c. Click Select Results File, select nr0.nrf.01, then click OK. d. Click Select Rslt Template File. e. Select pthemal_1_nodal.res_tmpl. f. Click OK. g. Click Apply. a b c d e f g Note: from within MSC.Patran the only indication that the analysis has successfully finished is the existence of an nrx.nrf.01 results file in a subdirectory one level below the working directory. c

WS6-22 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 12: Read And Plot Results (Cont.) Read results file and plot results a. Select Results: Create/Quick Plot application. b. In Select Result Cases select TIME: D+00/ HOURS c. Highlight Temperature for Select Fringe Result. d. Select the Fringe Attributes icon. e. Click on Label Style. f. Set Label Format to Fixed, Significant figures to 4, then click OK. g. Select Element Edges for Display. h. Click Apply. b c e f g h d a

WS6-23 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 12: Read And Plot Results (Cont.)

WS6-24 PAT312, Workshop 6, December 2006 Copyright 2007 MSC.Software Corporation Step 13: Quit MSC.Patran Quit MSC.Patran a. Select File on the Menu Bar and select Quit from the drop down menu a