WS6-1 WORKSHOP 6 TYPICAL AVIONICS FLOW NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation

WS6-2 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation

WS6-3 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation n Problem Description u This exercise involves modeling a compact heat exchanger consisting of five adjacent(congruent) ducts with air flowing through them. To model the exchange of heat from an advecting flow stream to a duct structure wall MSC.Patran can be used to associate fluid nodes to structure nodes using convection with what is called coupled advection. Coupled advection involves the combination of advection heat transfer with forced convection, with the convection being a boundary condition for the structure(conduction medium). u Also, heat flux is to be applied to the duct walls. u A steady-state thermal analysis is to be performed for this model.

WS6-4 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation

WS6-5 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation n Suggested Exercise Steps 1. Create a new database. 2. Set the thermal solver as MSC.Nastran 3. Create geometric surfaces for five ducts 4. IsoMesh all surfaces for five ducts 5. Mesh curve in each of the five ducts 6. Connect the finite elements using equivalence 7. Specify material properties 8. Define element properties 9. Apply a head load 10. Define the inlet temperature 11. Apply convection using coupled advection 12. Perform the thermal analysis 13. Attach the results file 14. Display the temperature results 15. Quit MSC.Patran

WS6-6 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 1: Create a New Database Create a new database. a.File: New b.Enter avionics_flow.db for File name. c.Click OK. c a b

WS6-7 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 2: Set the Thermal Solver as MSC.Nastran Choose MSC.Nastran Thermal as solver. a.Select Default for Tolerance. b.Select MSC.Nastran for Analysis Code. c.Select Thermal for Analysis Type. d.Click OK. b a c d

WS6-8 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 3: Create Geometric Surfaces for Five Ducts Create the geometry that represents the the compact heat exchanger with five rectangular ducts. a.Geometry: Create/Curve/XYZ b.Enter for Vector Coordinates List. c.Enter [0 0 0] for Origin Originates List. d.Click Apply. e.Geometry: Transform/ Curve/Translate. f.Select Cartesian in Refer. CF for Type of Transformation. g.Enter for Translation Vector. h.Enter Curve 1 for Curve List. i.Click Apply. c a b i g h f d e

WS6-9 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 3: Create Geometric Surfaces for Five Ducts (Cont.) a.Geometry: Create/Curve/Point. b.Select 2 Point for Option. c.Enter Point 1 for Starting Point List. d.Enter Point 3 for Ending Point List. e.Click Apply. f.Enter Point 2 for Starting Point List. g.Enter Point 4 for Ending Point List. h.Click Apply. c a b g h f d e c d

WS6-10 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 3: Create Geometric Surfaces for Five Ducts (Cont.) a.Geometry: Create/Surface/Extrude. b.Enter [0 0 0] for Origin of Scale and Rotate. c.Enter for Translation Vector. d.Enter Curve 1:4 for Curve List. e.Click Apply. c a b d e

WS6-11 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 3: Create Geometric Surfaces for Five Ducts (Cont.) Create a curve in the first duct. nGeometry: Create/Curve/XYZ. nEnter for Vector Coordinates List. nEnter [ ] for Origin Coordinates List. nClick Apply. Copy three surfaces four times to create the other ducts. e.Geometry: Transform/Surface/Translate. f.Select Cartesian in Refer. CF for Type of Transformation. g.Enter for Translation Vector. h.Enter 4 for Repeat Count. i.Enter Surface for Surface List. j.Click Apply. c a b j i g h f d e

WS6-12 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 3: Create Geometric Surfaces for Five Ducts (Cont.) Copy Curve 5 (in the first duct) four times, creating a curve in each of the other ducts. nGeometry: Transform/Curve/Translate. nEnter for Translation Vector. nEnter 4 for Repeat Count. nEnter Curve 5 for Curve List. nClick Apply. c a b d e

WS6-13 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 4: IsoMesh all Surfaces for Five Ducts IsoMesh all surfaces with CQUAD4 elements. a.Elements: Create/Mesh/Surface. b.Select Quad for Elem Shape. c.Select IsoMesh for Mesher. d.Select Quad4 for Topology. e.Enter Surface 1:16 for Surface List. f.Enter 0.25 for Value of Global Edge Length. g.Click Apply. c a b g f d e

WS6-14 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 5: Mesh Curve in Each of the Five Ducts Mesh Curves with Bar2 elements a.Elements: Create/Mesh/Curve. b.Select Bar2 for Topology. c.Enter Curve 5:9 for Curve List. d.Enter 0.25 for Value of Global Edge Length. e.Click Apply. c a b d e

WS6-15 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 6: Connect the Finite Elements Using Equivalence Equivalence the finite element nodes to connect the elements. a.Elements: Equivalence/All/Tolerance Cube. b.Enter for Equivalencing Tolerance. c.Click Apply c a b

WS6-16 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 7: Specify Material Properties Create the isotropic material property for aluminum. a.Materials: Create/Isotropic/Manual Input. b.Enter alum for Material Name. c.Click Input properties… d.Enter 4.0 for Thermal Conductivity. e.Click OK. f.Click Apply. c a b f d e

WS6-17 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 7: Specify Material Properties (Cont.) Create the isotropic material property for air. a.Materials: Create/Isotropic/Manual input. b.Enter air for Material Name. c.Click Input Properties… d.Enter 6.66e-4 for Thermal Conductivity. e.Enter for Specific Heat. f.Enter 5.01e-5 for Density. g.Enter 1.03e-6 for Dynamic Viscosity. h.Click OK. i.Click Apply c a b i g h f d e

WS6-18 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 8: Define Element Properties Create 2D shell element property for elements on the outside of the ducts (outside walls). a.Properties: Create/2D/Shell. b.Enter outside_wall for Property Set Name. c.Select Standard Formulation for Option(s). d.Click Input Properties.. e.Click in the Material Name box and select alum under Material Property Sets. f.Enter 0.05 for Thickness. g.Click OK. h.Enter Surface 1: :16 for Select Members. i.Click Add. j.Click Apply. c a b j i h d g f e h

WS6-19 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 8: Define Element Properties (Cont.) Create 2D shell element property for elements on the inside of the ducts (inside walls). nProperties: Create/2D/Shell. nEnter inner_walls for Property Set Name. nClick Input Properties… nClick in the Material Name box and select alum under Material Property Sets. nEnter 0.1 for Thickness. nClick OK. nEnter Surface 4:13:3 for Select Members. nClick Add. nClick Apply. c a b i g h f d e g

WS6-20 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 8: Define Element Properties (Cont.) Create 1D flow tube element property for bar elements on the curves inside of the ducts. a.Properties: Create/1D/Flow Tube. b.Enter air_flow for Property Set name. c.Click Input Properties… d.Click in Material Name box and select air under Material Property Sets. e.Enter for Hydraulic Diam. At Nod. f.Click OK. g.Enter Curve 5:9 for Select Members. h.Click Add. i.Click Apply. c a b i g h f d e

WS6-21 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 9: Apply a Head Load Apply a heat load on the top surface of each duct. a.Loads/BCs: Create/Applied Heat/Element Uniform. b.Select Normal Fluxes for Option. c.Enter flux for New Set Name. d.Select 2D for Target Element Type. e.Click Input Data… f.Enter 20 for Top Surf Heat Flux g.Click OK. h.Click Select Application Region… i.Enter Surface 2 6:15:3 for Select Surfaces or Edges. j.Click Add. k.Click OK. l.Click Apply c a b j i g h f d e k l

WS6-22 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 9: Apply a Head Load (Cont.)

WS6-23 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 10: Define the Inlet Temperature Define the air duct inlet temperature. a.Loads/BCs: Create/Temp/Nodal. b.Enter inlet_temp for New Set Name. c.Click Input Data… d.Enter 20 for Boundary Temperature. e.Click OK. f.Click Select Application Region… g.Enter Point 9 27:33:2 for Select Geometry Entities h.Click Add. i.Click Ok. j.Click Apply c a b j i g h f d e

WS6-24 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 10: Define the Inlet Temperature (Cont.)

WS6-25 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 11: Apply Convection Using Coupled Advection Apply convection using coupled advection. Five load sets, on for each channel, are defined for the fluid-structure coupling. a.Loads/BCs: Create/Convection/Element Uniform. b.Select Coupled Advection for Option. c.Enter conv1 for New Set Name. d.Select 2D for Target Element Type. e.Select 1D for Region 2. f.Click Input Data… g.Enter 0.3 for Top Surf Convection Coef. h.Enter 8.33e-3 for Mass Flow Rate. i.Click OK. j.Continue to next page. c a b i g h f d e

WS6-26 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 11: Apply Convection Using Coupled Advection (Cont.) a.Click Select Application Region. b.Select Closest Approach for Order. c.Enter Surface 1:4 for Select Surfaces or Edges. d.Click Add. e.Click Active List of Companion Region. f.Enter Curve 5 for Select Curves. g.Click Add. h.Click OK. i.Click Apply. j.Repeat the steps using the data in the table. c a b h i f d e

WS6-27 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 11: Apply Convection Using Coupled Advection (Cont.)

WS6-28 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 12: Perform the Thermal Analysis Perform the analysis. a.Analysis: Analyze/Entire Model/Full Run. b.Use for Job Name avionics_flow c.Click Apply a c b

WS6-29 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 13: Attach the Results File Attach the XDB file. a.Analysis: Attach XDB/Result Entities/Local b.Click Select Results File… c.Select avionics_flow.xdb d.Click OK. e.Click Apply c a b d e

WS6-30 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 14: Display the Temperature Results Display the results. a.Results: Create/Quick Plot b.Select SC1DEFAUL… for Select Result Cases c.Select Temperatures for Select Fringe Result. d.Click Apply. c a b d

WS6-31 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 14: Display the Temperature Results (Cont.)

WS6-32 NAS104, Workshop 6, March 2004 Copyright 2004 MSC.Software Corporation Step 15: Quit MSC.Patran Quit MSC.Patran a.Select File on the Menu Bar and select Quit from the drop down menu a