WS11-1 WORKSHOP 11 HEATING A BLOCK OF ICECREAM NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation

WS11-2 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation

WS11-3 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation n Problem Description u An ice cream block, 6 in by 6 in by 12 in, is initially at a uniform temperature of –12 F. It is suddenly exposed to air at 80 F. Determine the time to when thawing(melting) begins. The thermal conductivity of the ice cream block is k=1.26 Btu/hr/(ft*F). The heat transfer coefficient is h=1.55 Btu/hr/(ft**2*F).

WS11-4 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation n Suggested Exercise Steps 1. Create a database 2. Create a solid to be IsoMesh-ed 3. IsoMesh the solid with Hex20 elements 4. Define material property 5. Define element property 6. Create time dependent load case 7. Apply Loads/BCs for convection surrounding block 8. Perform transient thermal analysis 9. Attach XDB results file 10. View the temperature results 11. Plot temperature versus time to determine melting 12. Quit MSC.Patran

WS11-5 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 1: Create a Database Open a Database. a.File/New… b.Enter icecream for File name. c.Click OK. d.Click Default for Tolerance in New Model Preferences. e.Specify MSC.Nastran Thermal f.Click OK. a f d b c

WS11-6 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 2: Create a Solid to be IsoMesh-ed Create a solid. a.Geometry: Create/Solid/XYZ b.Enter for Vector Coordinates List. c.Enter [0 0 0] for Origin Coordinates List. d.Click Apply. a b c d

WS11-7 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 3: IsoMesh the Solid With Hex20 Elements IsoMesh the solid using Hex20 elements.. a.Elements: Create/Mesh/Solid b.Select Hex for Elem Shape. c.Select IsoMesh for Mesher. d.Select Hex20 Topology. e.Enter Solid 1 for Solid List. f.Enter for Global Edge Length. g.Click Apply. a b c e f g d

WS11-8 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 4: Define Material Property Define ice-cream material. a.Materials: Create/Isotropic/Manual Input b.Enter icecream for Material name. c.Click Input Properties… d.Enter 1.26 for Thermal Conductivity. e.Enter 25.2 for Specific Heat. f.Enter 1 for Density. g.Click OK. h.Click Apply. a b c e f g d h

WS11-9 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 5: Define Element Property Apply ice-cream material to the solid Hex20 mesh. a.Properties: Create/3D/Solid. b.Enter solid for Property Set Name. c.Click Input Properties… d.Click in the Material Name box and select icecream under Material Property Sets. e.Click OK. f.Select Solid 1 for Select Members. g.Click Add. h.Click Apply. a b c e f g d d h

WS11-10 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 6: Create Time Dependent Load Case Create time dependent load case. a.Load Case…/Create b.Enter tran for Load Case Name. c.Select Make Current d.Select Time Dependent for Load Case Type. e.Click Apply. a b d e c

WS11-11 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 7: Apply Loads/BCs for Convection Surrounding Block Apply loads/BCs for convection. a.Loads/BCs: Create/Convection/ Element Uniform. b.Select To Ambient for Option. c.Enter conv for New Set Name. d.Select 3D for Target Element Type. e.Click Input Data… f.Enter 1.55 for Convection Coefficient. g.Enter 80 for Ambient Temperature. h.Click Ok. i.Click Select Application Region… j.Select all solid faces, Solid , for Select Solid Faces. k.Click Add. l.Click OK. m.Click Apply. a b c e f g d h i j k l m

WS11-12 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 8: Perform Transient Thermal Analysis Analyze the entire model. a.Analysis: Analyze/Entire Model/Full Run. b.Enter ice_hex20 for Job Name. c.Click Solution Type. d.Select Transient analysis. e.Click Solution Parameters. f.Enter –12 for Default Init Temperature. g.Click OK. h.Click OK. i.Continued a b c e f g d h

WS11-13 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 8: Perform Transient Thermal Analysis (Cont.) a.Click Subcase Select… b.Select tran for Subcases for Solution Sequence: 159. c.Click OK. d.Click Apply a b c d

WS11-14 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 9: Attach XDB Results File Attach XDB file. a.Analysis: Attach XDB/ Result Entities/Local b.Click Select Results File… c.Select ice_hex20. xdb d.Click OK. e.Click Apply. a b d e c

WS11-15 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 10: View the Temperature Results View the temperature result. a.Results: Create/Quick Plot. b.Select SC1:TRAN, A1 Time=0.49 under Select Result Cases c.Select Temperature for Select Fringe Result. d.Click Apply. a b c d

WS11-16 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 11: Plot Temperature Versus Time to Determine Melting Determine time to beginning of melting. a.Results: Create/Graph/Y vs. X b.Select all the result cases. c.Select Temperature for Select Y Result. d.Click Target Entities. e.Enter Node 769 for Select Nodes; the node is at a corner of the block. f.Click Apply. a b c e f d

WS11-17 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 11: Plot Temperature Versus Time to Determine Melting (Cont.) It can be seen that at about 0.53 hours melting begins; the temperature is about 32 F

WS11-18 NAS104, Workshop 11, March 2004 Copyright 2004 MSC.Software Corporation Step 12: Quit MSC.Patran Quit MSC.Patran a.Select File on the Menu Bar and select Quit from the drop down menu a