PAT312, Section 63, December 2006 S63-1 Copyright 2007 MSC.Software Corporation SECTION 63 ORGANIZING A VIEW FACTOR JOB

PAT312, Section 63, December 2006 S63-2 Copyright 2007 MSC.Software Corporation

PAT312, Section 63, December 2006 S63-3 Copyright 2007 MSC.Software Corporation GENERAL STRUCTURE Defined in LBC Form Enclosure ID VFAC Template ID Points into template.dat.apnd file Convex Surface ID Ambient Node ID Participating Media Node ID Obstruction Flag Top/Bottom Surface Switch

PAT312, Section 63, December 2006 S63-4 Copyright 2007 MSC.Software Corporation DEFINITIONS Enclosure ID Surfaces with different Enclosure IDs do not see each other. VFAC ID LBCs with different emissivities need separate VFAC template IDs and therefore separate LBCs

PAT312, Section 63, December 2006 S63-5 Copyright 2007 MSC.Software Corporation DEFINITIONS (Cont.) Convex surface ID LBCs with the same ID do not see each other Ambient node ID Node number of the ambient environment node Participating media node ID Node number of the participating media node Obstruction Flag Can the entities in this LBC obstruct others in same enclosure? Top/Bottom Surface Switch For 2D application regions, Top matches surface normal direction

PAT312, Section 63, December 2006 S63-6 Copyright 2007 MSC.Software Corporation ORGANIZATION EXAMPLE Enclosure 1 Enclosure 2 Convex ID 2, e = 0.7, LBC_C, bottomConvex ID 2, e = 0.85, LBC_D, top Convex ID 1, e = 0.85, LBC_B, bottom Convex ID null, e = 0.8, LBC_A, top Ambient Node 99

PAT312, Section 63, December 2006 S63-7 Copyright 2007 MSC.Software Corporation ORGANIZATION EXAMPLE (Cont.) LBC_ALBC_B LBC_C Node 99

PAT312, Section 63, December 2006 S63-8 Copyright 2007 MSC.Software Corporation ORGANIZATION EXAMPLE (Cont.) LBC_Dtemplate.dat.apnd * LBC A VFAC * LBC B and D VFAC * LBC C VFAC

PAT312, Section 63, December 2006 S63-9 Copyright 2007 MSC.Software Corporation IMPROVING PERFORMANCE OF RADIATION INTERCHANGE MODELS 5 features of MSC.Thermal Viewfactor maximize execution speed and minimize memory and storage Maximizing the number of Enclosures in a model Reduces execution time by reducing viewfactor combinations The Convex Surface ID Flag in the LBC form Reduces execution time by eliminating viewfactor and obstruction calculation for convex element surfaces The non-Obstruction Flag in the LBC form Reduces execution time for obstruction determination The Collapse Flag in the VFAC template definition Reduces file storage demand by collapsing nodal subelement radiosity nodes and resistors Maximizing the use of Radiation symmetry Reduces execution time and storage demand by minimizing the overall model size

PAT312, Section 63, December 2006 S63-10 Copyright 2007 MSC.Software Corporation

PAT312, Section 63, December 2006 S63-11 Copyright 2007 MSC.Software Corporation

PAT312, Section 63, December 2006 S63-12 Copyright 2007 MSC.Software Corporation