PAT312, Section 37, December 2006 S37-1 Copyright 2007 MSC.Software Corporation SECTION 37 LOADS AND BOUNDARY CONDITIONS

PAT312, Section 37, December 2006 S37-2 Copyright 2007 MSC.Software Corporation

PAT312, Section 37, December 2006 S37-3 Copyright 2007 MSC.Software Corporation LOADS AND BOUNDARY CONDITIONS l Load and Boundary Conditions are invoked from the Load/BCs Applications l The following pages describe the Load and Boundary Conditions form l Included are details of the load and boundary conditions supported by MSC.Patran Thermal

PAT312, Section 37, December 2006 S37-4 Copyright 2007 MSC.Software Corporation LOADS AND BOUNDARY CONDITIONS l Load/Boundary Conditions form l Defines the type of load l Temperature, Heating, etc. l Defines the type of application region l Defines the target element type l 1D, 2D, 3D l Generates the Input Data form l Select the Application Region(s) l More detail in MSC.Patran Users Manual, Functional Assignments

PAT312, Section 37, December 2006 S37-5 Copyright 2007 MSC.Software Corporation THERMAL LBC TYPES l The following table outlines the options for Thermal LBCs ObjectTypeOption RadiationElement UniformAmbient node Gap Radiation Template, View Factors Spacecraft STEP_TAS ConventionElement Uniform Element Variable Fixed Coefficient Time Table CMA Boundary Conditions Temperature Table Template, Convection Spatial Field (Time) HeatingElement Uniform Element Variable Flux, Fixed Flux, Time Table Flux, Temperature Table Template, Fluxes Template, Volumetric Heat Template, Nodal Source Spatial Field (Time) Mass Flow Rate (Hydraulic network LBC) NodalFixed Initial Time Table Template Pressure (Hydraulic network LBC) NodalFixed Initial Time Table Template TemperatureNodalFixed Coupled Template Time Table Initial

PAT312, Section 37, December 2006 S37-6 Copyright 2007 MSC.Software Corporation INPUT DATA l Invoked with the Input Data button l The information on the input form varies: l By Object l By Target Element type l Shown are typical inputs for a Template,Temperature l Multiplier is applied to the field values returned l Default (blank) is 1.0 l Spatial fields defined in the database can be selected from a list l TID points to MACRO template for time or temperature dependent LBCs

PAT312, Section 37, December 2006 S37-7 Copyright 2007 MSC.Software Corporation TEMPLATE BOUNDARY CONDITIONS l MSC.Thermal uses a pointer structure to apply variable boundary conditions l Template ID points into template.dat file l MACRO template l Functional variation is constructed by this template l Points to microfunction (field) data l Optionally, Multiplier is applied to field results l Spatial fields are selected directly l Template is not required

PAT312, Section 37, December 2006 S37-8 Copyright 2007 MSC.Software Corporation APPLICATION REGIONS l Form customized for: l Target Element Type l Nodal l 1D, 2D, 3D l Standard or l 2-region LBCs l Both FEM or l Both Geometry l LBC type l Element vs. nodal

PAT312, Section 37, December 2006 S37-9 Copyright 2007 MSC.Software Corporation TEMPERATURE BOUNDARY CONDITIONS l Options for Temperature Boundary Condition l Fixed l Isothermal boundary l Spatially varying Temperature l Time Table l Input temperature vs. time l Coupled l Closest Approach or Selection l Initial l Initial value for steady state l Temperature at initial time for transient l Overrides global initial temperature l Template l TID points to functional (field) variation l Time

PAT312, Section 37, December 2006 S37-10 Copyright 2007 MSC.Software Corporation HEATING BOUNDARY CONDITIONS l Fixed l Input a fixed flux (e.g. W/m 2 ) l Time table l Input heat flux vs. time in tabular form l Temperature table l Input heat flux vs. temperature l Template l Input TID and multiplier l TID points to MACRO template l Template, Volumetric heat l Fixed or Template flux (e.g. W/m 3 ) l Template, Nodal Source l Fixed or Template heat (W/node) l Spatial Field (time) l Use Field, Spatial, Tabular (Time)

PAT312, Section 37, December 2006 S37-11 Copyright 2007 MSC.Software Corporation FIXED HEAT FLUX l Heat flux is an elemental quantity l Applied as Element Uniform (default) l Element variable l These pertain to spatial variations l Input the heat flux value l Optionally, select a spatial field l Set Target Element Type l Element type underlying the application region l e.g. Face of a solid element l Select 3D

PAT312, Section 37, December 2006 S37-12 Copyright 2007 MSC.Software Corporation TIME TABLE HEAT FLUX l Input heat vs. time values l Name table l Existing tables can be re-used l Simplified entry, same as: l Template, heating l MACRO template l Non-spatial field (time)

PAT312, Section 37, December 2006 S37-13 Copyright 2007 MSC.Software Corporation TEMPERATURE TABLE HEAT FLUX l Input heat flux vs. temperature values l Name table l Existing tables can be reused l Simplified entry, same as: l Template heating l MACRO template l Non-spatial field (temperature) l Temperatures evaluated node-by-node

PAT312, Section 37, December 2006 S37-14 Copyright 2007 MSC.Software Corporation TEMPLATE FLUX l Enter constant heat source (fixed) value, or: l Template ID points into template.dat file l MACRO template l Non-spatial field functional variation l Optional Heat Flux multiplier l Area type application region l Surfaces l Shell elements l Faces of solids or solid elements

PAT312, Section 37, December 2006 S37-15 Copyright 2007 MSC.Software Corporation FLUX, SPATIAL FIELD (TIME) l Spatial, time fields l Create in Fields: l Spatial, Tabular input l Select Independent variables l Select Time dynamic variable

PAT312, Section 37, December 2006 S37-16 Copyright 2007 MSC.Software Corporation VOLUMETRIC HEAT SOURCE BOUNDARY CONDITION l Input the volumetric heat flux value l e.g. W/m 3, OR l Uncheck Fixed l Template ID points into: l MACRO template l Non-spatial field functional variation l Optional heat flux multiplier l Volume type application region l Solids l Solid elements

PAT312, Section 37, December 2006 S37-17 Copyright 2007 MSC.Software Corporation ELEMENT VARIABLE AND UNIFORM l Element variable heat flux is same as element uniform unless there is a spatial variation l If the LBC value is spatially varying, the Element Variable type specifies that data will be evaluated at the element nodes. (varies across the element) l The Element Uniform type is evaluated at the center of the element edge for scaling based on unit length or element face for scaling based on area l Same concept applies to spatially varying convection, temperature and volumetric heat flux

PAT312, Section 37, December 2006 S37-18 Copyright 2007 MSC.Software Corporation CONVECTION BOUNDARY CONDITIONS l Fixed l Input a fixed coefficient l Between regions convection l Time table l Input coefficient vs. time l Temperature table l Input coefficient vs. temperature l Template l Input TID and multiplier l TID points to Material Property template l CMA Boundary conditions l Set-up for CMA ablation analysis l Spatial Field (time) l Use Field, Spatial, Tabular (Time)

PAT312, Section 37, December 2006 S37-19 Copyright 2007 MSC.Software Corporation FIXED COEFFICIENT CONVECTION l Constant or spatially varying coefficient l Between regions LBC l Closest approach l Most robust connection option l Both regions must use same geometry filter l Area for computation comes from the Application Region l Time table and temperature table convection are also Between Regions LBCs

PAT312, Section 37, December 2006 S37-20 Copyright 2007 MSC.Software Corporation TEMPLATE CONVECTION l Enter constant coefficient (fixed), or: l Optional GP2/GP3 input l Generally used for spatial dependency l e.g. characteristic lengths l Template ID points into template.dat file l CONV template l Material Property field functional variation l GPs and MPIDs input via template l Select a single fluid node ID l Need not be associated with geometry l Can have fixed temperature applied l Convection coefficient can be defined using configuration library

PAT312, Section 37, December 2006 S37-21 Copyright 2007 MSC.Software Corporation TIME OR TEMPERATURE DEPENDENT LBCS l Temperature or Heat l Create LBC using Template ID l Create Field/Non Spatial/General l Create micro function with MFID l Edit template.dat.apnd l Include MACRO linking TID to MFID l MACRO TID # of MFIDs Node1 Node2 Scale Factor l MFID l Convection by user defined time or temperature function l Create LBC using Template ID l Create Field/Material Property/General l Create material property function h(t or T) with MPID l Edit template.dat.apnd using Analysis, Build Template l Include CONV linking TID to MPID for configuration 29 l CONV TID l MPID

PAT312, Section 37, December 2006 S37-22 Copyright 2007 MSC.Software Corporation TIME OR TEMPERATURE DEPENDENT LBCS (Cont.) l Convection by MSC.Patran Configuration Library (see P3/THERMAL User Manual. Vol. 1) l Create LBC using Template, Convection l Uncheck Fixed l Include value for GP2 and GP3 in Conv GP2/GP3 l Or, leave Conv GP2/GP3 blank for GP2 and GP3 defined in template.dat.apnd l Edit template.dat.apnd using Analysis, Build Template l Include CONV linking TID to MPID for configuration CFIG l CONV TID CGIF # of GPs defined here # of MPIDs supplied here l GPs l MPIDs

PAT312, Section 37, December 2006 S37-23 Copyright 2007 MSC.Software Corporation

PAT312, Section 37, December 2006 S37-24 Copyright 2007 MSC.Software Corporation