WORKSHOP 7 AN OVEN WINDOW DESIGN

WS7-2 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation

WS7-3 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Model Description In this exercise you will model a 2D planar section of an oven window. You will learn how to initiate and use Utilities which facilitate this task. A manufacturer of appliances is proposing a self cleaning oven design that uses a composite window separating the oven cavity from room air. The composite consists of two high temperature plastics (A & B) whose physical and thermal attributes are shown below. The combined convection / linearized radiation heat transfer parameters for inside and outside of the oven are also shown (Note: Radiation will be linearized and is included in the heat transfer coefficient). The design specification for safe operation requires an outside oven temperature of 50°C or less. The following assumptions can be made for the model. Steady-state conditions exist. The oven door can be modeled as a 2-dimensional slice. Contact resistance is negligible. Each plastic is homogeneous with constant properties.

WS7-4 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation

WS7-5 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Information on Utilities: Utilities refer to a set of tools which facilitate the use of MSC.Patran. These tools are supplied with MSC.Patran. In Version 9.0 they are located on each CD ROM. Utilities are written or supplied by MSC.Software software developers, application engineers, and anyone within MSC who has a good idea for improving MSC.Patran functionality. Sometimes Utilities are the vehicle for implementing an improvement which for organizational reasons will not be officially implemented within a reasonable release horizon. Utilities are written in PCL, MSC.Patran Command Language. Since Utilities are developed from the personal initiative of individuals and not as part of the MSC.Software corporate software development strategy, they are not subjected to any formal quality assurance testing. Hence, they are supplied by MSC.Software as a courtesy but they are officially not supported by MSC.Software. Most Utilities are supplied with the authors name, an address, and telephone number. If you have a problem with a Utilities tool you may contact the author if ownership data is available. You may report suspected or identified problems with Utilities to the MSC.Patran support line but no obligation to fix the Utilities problem is incurred by MSC.Software. That being said, Utilities is generally reliable and quite handy. Most intermediate and advanced user of MSC/PATRAN install and use Utilities. Load the MSC.Patran CD in the CD-ROM drive and mount the CD-ROM drive Installation instructions are listed in Installing PCL Utilities and MSC.Software Institute Files on Unix pg 43 of MSC.Patran Installation and Operation Guide. Instructions for Windows NT are found on pg. 65.

WS7-6 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Information on Utilities (cont.) If the user has installed MSC.Patran with the Full install option, Utilities are loaded automatically. If user selects CUSTOM installation, then PCL Utilities must be selected as an option under the MSC.Patran Core Application. When loaded (installed) Utilities are initiated by copying the p3epilog.pcl file from /shareware/msc/unsupported/utilities (e.g.,/patran/patran3/ shareware/msc/unsupported/utilities/p3epilog.pcl), into a users home directory (for user-by-user access) or the P3_HOME directory (for a system wide access). Once the p3epilog.pcl file in place Utilities is available as a pick on the Menu bar after re-starting MSC.Patran. Objectives Model a 2D planar slice of an oven window Learn how to initiate and use Utilities

WS7-7 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Exercise Overview 1. Create a new database named exercise_07.db. Set Approximate Maximum Model Dimension to 0.20, and the Analysis Code to MSC/Thermal. 2. Create two surfaces which define the oven window geometry. 3. Mesh the surfaces with an IsoMesh, Global Edge Length of Create two fluid nodes 9998 and 9999 for the oven interior and ambient conditions respectively. 5. Equivalence the nodes at the mating surface edges. 6. Define the two material properties for the plastics. 7. Apply element properties to the elements using the defined materials. There are Thermal 2D elements. 8. Use the Fields Form to define the temperature distribution at the interior pane upper edge. 9. Apply temperature and convection boundary conditions. 10. Visualize and verify the convection LBCs using Utilities/Thermal/Thermal BC Display…. 11. Prepare and submit the model for analysis specifying that it is a 2D Plane Geometry model and that the Weakly Nonlinear Solution solver will be used for analysis. 12. Read the results file and plot results. 13. Check the results against the requirement of 50°C. 14. Quit MSC.Patran.

WS7-8 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 1: Create a New Database Create a new database called exercise_07.db. a. File / New. b. Enter exercise_07 as the file name. c. Click OK. d. Choose Based on Model, and set model dimension to e. Select MSC.Patran Thermal as Analysis Code. f. Select Thermal as Analysis Type. g. Click OK. a b c d e f g

WS7-9 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 2: Create the Oven Window Create two surfaces which define the oven window geometry. a. Geometry b. Create/Surface/ XYZ. c. Enter for Vector Coordinate List. d. Apply. e. Turn on Labels using Show Labels icon. a b c d e

WS7-10 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 2: Create the Oven Window Create the second surface. a. Enter the second Vector Coordinate List,. b. Select Point 4 from the viewport for Origin Coordinate List c. Apply. a b c

WS7-11 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 3: IsoMesh the Surfaces Mesh surfaces with IsoMesh, using a global edge length of a. Finite Elements. b. Create/Mesh/ Surface. c. Turn off Automatic Calculation, and enter for Global Edge Length. d. Click in Surface List box and drag a rectangle around both surfaces. e. Click Apply. f. Turn off labels using the following icon. a b c e f d

WS7-12 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 4: Create an Ambient and Over Interior Node Create two fluid nodes, Node 9998 and Node 9999 for the oven interior and ambient conditions, respectively. a. Finite Elements. b. Create/Node/ Edit. c. Enter 9998 for Node ID List. d. Unselect Associate with Geometry. e. Enter [ ] for Node Location List. f. Click Apply. g. Under Finite Elements enter [ ] for Node Location List for the second node, Node h. Click Apply. a b c d e f g h

WS7-13 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 4: Create an Ambient Node Increase the size of the node markers for display to facilitate the application of the boundary conditions. a. Click on Display from the main menu. b. Select Finite Elements from the drop down menu. c. Select 6 for Node Size. d. Click Apply, then Cancel. a b c d

WS7-14 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 5: Equivalence Nodes to Connect Elements Equivalence the nodes at the interface of the surfaces. a. Under Finite Elements specify Equivalence/All/ Tolerance Cube. b. Click Apply. a b

WS7-15 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 6: Define Two Materials Define the two material properties for the plastics. a. Materials. b. Create/Isotropic/Manual Input. c. Enter ka for Material Name. d. Click on Input Properties. e. Enter for Thermal Conductivity, 1.0 for Density, and 1.0 for Specific Heat. f. Click OK, then Apply. g. Repeat this procedure using kb for Material Name, 0.07 for Thermal Conductivity, 1.0 for Density, and 1.0 for Specific Heat. h. OK. i. Apply. a c d e g b h Note: since this will be a steady state analysis, thermal conductivity is the only material property used in the solution f f

WS7-16 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 7: Apply Element Properties Apply element properties to the elements using the defined materials. a. Properties. b. Create/2D/Thermal 2D. c. Under Property Set Name enter interior_pane. d. Click on Input Properties… e. For Material Name select ka from Material Property Sets box. f. OK. g. Under Select Members, select Surface 1(left side). h. Click Add, then Apply. i. Repeat this procedure using exterior_pane for Property Set name. j. Under Input Properties, select kb from Material Property Sets. k. OK. l. Under Select Member select Surface 2 (right side). m. Click Add, then Apply. a e f b c d h e g

WS7-17 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 8: Create a Spatial Field Define the temperature distribution at the interior pane upper edge. a. Fields. b. Create/Spatial/Tabular Input. c. Under Field Name enter edge_T. d. Click on Input Data… e. Under Data select cell X 1. f. Enter 0.0 for Input Scalar Data. g. Enter 0.05 for Input Scalar Data. h. Under Data select cell Value 1. i. Enter for Input Scalar Data. j. Enter 38.0 for Input Scalar Data. k. OK. l. Apply. a b c d e k l h

WS7-18 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 9: Apply Boundary Conditions Apply temperature and convection boundary conditions. a. Loads/BCs. b. Create/Temperature/Nodal. c. Under Option select Fixed. d. Enter oven for New Set Name. e. Click on Input Data… f. Enter for Fixed Temperature. g. Click OK. h. Click on Select Application Region… i. Click on FEM filter. j. Select Node 9998 for Select Nodes. k. Add. l. OK. m. Apply. a f g b d e c m h i j k l Node 9998

WS7-19 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 9: Apply Boundary Conditions Repeat the steps to create another fixed temperature boundary condition. a. Under Loads/BCs enter ambient for New Set Name. b. Click on Input Data. c. Enter 24.0 for Fixed Temperature. d. Click OK. e. Click on Select Application Region… f. Select Node 9999 under Select Nodes. g. Add. h. OK. i. Apply. a b c d e f g h i a

WS7-20 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 9: Apply Boundary Conditions Create the temperature distribution along an edge. a. Under Loads/BCs enter edge for New Set Name. b. Click on Input Data. c. Click on Select Spatial Field… d. Under Spatial Fields select edge_T. e. Click OK. f. Click on Select Application Region… g. Select the Geometry filter. h. In the select menu select Curve or Edge icon. i. Click in the Select Geometric Entities box, and select the upper edge of the interior pane, Surface 1.2. j. Add. k. OK. l. Apply. a b f l g c e i j k h i

WS7-21 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 9: Apply Boundary Conditions Create the heat transfer coefficient boundary conditions. a. Under Loads/BCs select Create/Convection/Element Uniform. b. Under Option select Template, Convection. c. Under New Set Name type oven_convection. d. Under Target Element Type select 2D. e. Click on Input Data, and specify in 16.0 for Convection Coefficient. f. Under Fluid Node ID select Node g. Click OK. h. Click Select Application Region…. i. Click the Geometry filter. j. Under Select Surfaces or Edges select the left oven window edge using the Edge select filter icon. k. Click Add, OK, and Apply. f g a b c d e h e j i k j k

WS7-22 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 9: Apply Boundary Conditions Create the heat transfer coefficient boundary conditions. a. Under New Set Name specify air_convection. b. Under Target Element Type select 2D. c. Click on Input Data, and specify 13.0 for Convection Coefficient. d. Under Fluid Node ID select Node e. Click OK. f. Click Select Application Region... g. Under Select Surfaces or Edges select the right oven window edge by using the Edge icon. h. Add. i. OK. j. Apply. a b c f j g

WS7-23 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 10: Visualize and Verify the Convection Visualize and verify the convection LBCs. a. Click Utilities from the main menu. b. Click Thermal, then Thermal BC Display… c. Click OK. d. Select set of LBCs, then click Apply. e. Use Clear and Close to revert to normal display. f. Reduce the node size. a b d e e Note: shareware contains various utilities for facilitative model creation and LBCs verification. Verify the convective coupling by drawing a vector from the centroid of each element to the associated fluid node using Thermal/Thermal BC Display.. d

WS7-24 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 11: Prepare and Run Analysis Prepare and submit the model for analysis. a. Analysis. b. Analyze/Full Model/ Full Run. c. Click on Translation Parameters, and under Model Dimensionality click on 2D Plane Geometry, XY co-ordinates. d. OK. e. Click on Solution Parameters, and click Celsius for Calculation Temperature Scale. f. Under Solver Option, Click 1, Weakly Nonlinear Solution, and Click OK. g. Click on Output Requests…, and under Units Scale for Output Temperatures click Celsius. h. OK. i. Apply. a b c e g f h d i e f g

WS7-25 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 12: Read and Plot Results Read results file and plot results. a. Under Analysis set to Read Result/Result Entities. b. Click on Select Results File… c. Under directories select the path that will lead to exercise_07. d. Under Available Files select nr0.nrf.01. e. OK. f. Click on Select Rslt Template File… g. Under Files name select pthermal_1_nodal.res_tmpl. h. OK. i. Apply. a b c f g h i e d

WS7-26 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 12: Read and Plot Results Plot the results. a. Results. b. Create/Quick Plot. c. Under Select Result Cases click on TIME: D+00S.. d. Under Select Fringe Result click Temperature. e. Select the Fringe Attributes icon. f. Under Display click on Element Edges. g. Click on Label Style… h. Under Label Format select Fixed. i. Using the slide bar select 4 for Significant figures. j. OK. k. Apply. l. The model should now appear as follows. a b e f g i k h j c d

WS7-27 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 13: Check the Results What is the exterior temperature of the oven window? Is it at or below the required maximum of 50° C?

WS7-28 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation Step 14: Quit MSC.Patran Quit MSC.Patran. a.Select File. b.Click Quit from the drop down menu.

WS7-29 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation

WS7-30 PAT312, Workshop 7, December 2006 Copyright 2007 MSC.Software Corporation