WS13-1 WORKSHOP 13 DIRECTIONAL HEAT LOADS NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation

WS13-2 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation

WS13-3 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation n Problem Description u For this example apply a directional heat load on a cylindrical surface. Orient the surface normal, using the right hand rule, so that it points away from the cylinder. The incoming directional heat flux is specified as relative to the normal. A typical application of this directional heat load process is in an orbital heating environment. u The dimension of the cylinder is 1.5 inch in diameter with a length of 6 inches. The material is aluminum with a thermal conductivity of 3.96 Watts/(in*C). The directional heat load is 30 Watts/in 2. The exterior surface of the cylinder looses heat by radiation to space. The radiation view factor is 1.0 and the ambient temperature is 20 o C. The absorptivity and emissivity of the cylinder surface is 0.8.

WS13-4 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation

WS13-5 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation n Suggested Exercise Steps 1. Create a new database. 2. Specify MSC.Nastran as Thermal Solver 3. Create a cylindrical surface 4. IsoMesh the surface 5. Connect elements at geometric boundaries 6. Specify material property 7. Define element property 8. Apply a directional heat load 9. Apply a radiation boundary condition 10. Display all thermal boundary conditions 11. Perform the thermal analysis 12. Attach the results file 13. Display the temperature results 14. Quit MSC.Patran

WS13-6 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 1: Create a New Database Create a new database. a.File/New b.Enter direct_heat for File name. c.Click OK. c a b

WS13-7 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 2: Specify MSC.Nastran as Thermal Solver Specify thermal solver. a.Select Default for Tolerance. b.Select MSC.Nastran for Analysis Code. c.Select Thermal for Analysis Type. d.Click OK. c a b d

WS13-8 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 3: Create a Cylindrical Surface Create a point, then revolve it to create a curve. a.Geometry: Create/Point/XYZ b.Enter [ ] for Point Coordinates List. c.Click Apply. d.Greometry: Create/Curve/Revolve. e.Enter 360 for Total Angle. f.Enter Point 1 for Point List. g.Click Apply. c a b g f d e

WS13-9 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 3: Create a Cylindrical Surface (Cont.) Extrude the curve to create a cylindrical surface. nGeometry: Create/Surface/Extrude. nEnter for Translation Vector. nEnter Curve 1 for Curve List. nClick Apply. nChange the view to Iso 1 View. nShow some display-lines c a b d e f

WS13-10 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 3: Create a Cylindrical Surface (Cont.) a.Geometry: Show/Surface/Normal. b.Click Front view icon. c.Enter Surface 1 for Surface List. d.Click Apply. e.Continued. c a b d

WS13-11 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 3: Create a Cylindrical Surface (Cont.) Reverse the surface normal so it is pointed away from the cylinder. nGeometry: Edit/Surface/Reverse. nEnter Surface 1 for Surface List. nClick Apply.

WS13-12 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 4: IsoMesh the Surface Create finite elements using IsoMesh. a.Elements:Create/Mesh/Surface. b.Select Quad for Elem Shape. c.Select IsoMesh for Mesher. d.Select Quad4 for Topology. e.Enter Surface 1 for Surface List. f.Enter 0.1 for Value of Global Edge Length. g.Click Apply. c a b g f d e

WS13-13 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 5: Connect Elements at Geometric Boundaries Connect elements at coincident geometric edges. a.Elements: Equivalence/All/Tolerance Cube. b.Enter for Equivalency Tolerance. c.Click Apply. c a b

WS13-14 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 6: Specify Material Property Specify material property a.Materials: Create/Isotropic/Manual Input. b.Enter alum for Material Name. c.Click Input Properties… d.Select Solid properties for Constitutive Model. e.Enter 3.96 for Thermal Conductivity. f.Click OK. g.Click Apply. c a b g f d e

WS13-15 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 7: Define Element Property Define 2D shell element property a.Properties: Create/2D/Shell b.Enter alum for Property Set Name. c.Select Standard Formulation for Option. d.Click Input Properties.. e.Click in Material Name box and select alum under Material Property Sets. f.Enter for Thickness. g.Click OK. h.Enter Surface 1 for Select Members. i.Click Add. j.Click Apply. c a b j i g h f d e

WS13-16 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 8: Apply a Directional Heat Load Apply a directional heat load. a.Loads/BCs: Create/Applied Heat/Element Uniform. b.Select Directional Fluxes for Option. c.Enter vector_flux for New Set Name. d.Select 2D for Target Element Type. e.Click Input Data… f.Select Top for Surface Option. g.Enter 0.8 for Top Surf Absorptivity. h.Enter 30 for Top Surf Heat Flux i.Enter for incident Thermal Vector. j.Click OK. k.Click Select Application Region l.Enter Surface 1 for Select Surfaces or Edges. m.Click Add. n.Click OK. o.Click Apply. c a b j i g h f d e k l m n o

WS13-17 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 8: Apply a Directional Heat Load (Cont.)

WS13-18 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 9: Apply a Radiation Boundary Condition Apply a radiation boundary condition. a.Loads/BCs: Create/Radiation/Element Uniform. b.Select Ambient Space for Option. c.Enter rad_space for New Set Name. d.Select 2D for Target Element Type. e.Click Input Data.. f.Enter 0.8 for Top Surf Emissivity. g.Enter 0.8 for Top Surf Absorptivity. h.Enter 20 for Ambient Temperature. i.Enter 1.0 for View Factor. j.Click OK. k.Click Select Application Region… l.Enter Surface 1 for Select Surfaces or Edges. m.Click Add. n.Click OK. o.Click Apply. c a b j i g h f d e o n l m k

WS13-19 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 10: All Thermal Boundary Conditions

WS13-20 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 11: Perform the Thermal Analysis Perform the steady-state thermal analysis. a.Analysis: Analyze/Entire Model/Full Run. b.Enter direct_heat for Job Name. c.Click Solution Type… d.Click Solution Parameters… e.Click Radiation Parameters.. f.Select Degree Celsius for Absolute Temperature Scale. g.Select E-11 WATTS/IN2/K4 h.Click OK. i.Click OK. j.Click OK. k.Click Apply. c a b j i g h f d e k

WS13-21 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 12: Attach the Results File Attach the results file. a.Analysis: Attach XDB/Result Entities/Local. b.Click Select Results File… c.Select direct_heat.xdb for File name. d.Click OK. e.Click Apply. b a e d c

WS13-22 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 13: Display the Temperature Results Display the results. a.Results:Create/Quick Plot. b.Select SC1DEFAULT,A1.. for Select Result Cases. c.Select Temperatures for Select Fringe Result. d.Click Apply. c a b d

WS13-23 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation Step 14: Quit MSC.Patran Quit MSC.Patran a.Select File on the Menu Bar and select Quit from the drop down menu a

WS13-24 NAS104, Workshop 13, March 2004 Copyright 2004 MSC.Software Corporation