Purpose

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The general procedure for performing a thermal radiation analysis is:

Patran	Build model and assign boundary conditions.
Analysis Menu	Select Viewfactor Solution under Solution Type.
Hit Apply	This executes a script that will check for obstructions, calculate viewfactors and make radiation resistors for Patran Thermal.
Analysis Menu	If a thermal analysis was requested under solution type, following the Viewfactor analysis, Patran Thermal will create a QTRAN source file for the problem and perform the thermal network analysis.
Patran	Display the results.

Patran

Build model and assign boundary conditions.

Analysis Menu

Select Viewfactor Solution under Solution Type.

Hit Apply

This executes a script that will check for obstructions, calculate viewfactors and make radiation resistors for Patran Thermal.

Analysis Menu

If a thermal analysis was requested under solution type, following the Viewfactor analysis, Patran Thermal will create a QTRAN source file for the problem and perform the thermal network analysis.

Patran

Display the results.

Parameter	Description
UID	User template ID.
MEDNOD	Participating media node if any Flag for top or bottom of shell.
AMBNOD	Ambient or space node.
CNVSID	Convex surface ID.
NONOBSTRUCTING FLAG	Flag for nonobstructing surface.
TOP/BOTTOM FLAG	Flag for top or bottom of shell.
ENCLOSURE ID	Enclosure ID.

Parameter

Description

UID

User template ID.

MEDNOD

Participating media node if any Flag for top or bottom of shell.

AMBNOD

Ambient or space node.

CNVSID

Convex surface ID.

NONOBSTRUCTING FLAG

Flag for nonobstructing surface.

TOP/BOTTOM FLAG

Flag for top or bottom of shell.

ENCLOSURE ID

Enclosure ID.

The surfaces on which the VFAC boundary conditions are applied are defined under Application Region.

The VFAC Template in the Patran Thermal TEMPLATEDAT file has the form:

Parameter	Description
TID	Integer, Template ID.
nbands	Integer, Optional, Default = 0, Number of wavebands in this template.
epsilon	Real, surface emissivity.
tau	Real, Optional, Default = 1.0, Participating media transmissivity (kflag = 0) or extinction coefficient (kflag = 1).
empid	Integer, Optional, Default = 0, Emissivity material property ID.
tmpid	Integer, Optional, Default = 0, Transmissivity (kflag = 0) or extinction coefficient (kflag = 1) material property ID.
lambda1	Real, Optional, Default = 0.0, Waveband beginning wavelength, microns.
lambda2	Real, Optional, Default = 0.0, Waveband ending wavelength, microns.
kflag	Integer, Optional, Default = 0, Flag that tau or tmpid refer to transmissivity (kflag = 1) or to extinction coefficient (kflag = 1).
collapse	Integer, Optional, Default = 0, ID to control the collapsing of radiosity nodes associated with a surface node.

Parameter

Description

TID

Integer, Template ID.

nbands

Integer, Optional, Default = 0, Number of wavebands in this template.

epsilon

Real, surface emissivity.

tau

Real, Optional, Default = 1.0, Participating media transmissivity (kflag = 0) or extinction coefficient (kflag = 1).

empid

Integer, Optional, Default = 0, Emissivity material property ID.

tmpid

Integer, Optional, Default = 0, Transmissivity (kflag = 0) or extinction coefficient (kflag = 1) material property ID.

lambda1

Real, Optional, Default = 0.0, Waveband beginning wavelength, microns.

lambda2

Real, Optional, Default = 0.0, Waveband ending wavelength, microns.

kflag

Integer, Optional, Default = 0, Flag that tau or tmpid refer to transmissivity (kflag = 1) or to extinction coefficient (kflag = 1).

collapse

Integer, Optional, Default = 0, ID to control the collapsing of radiosity nodes associated with a surface node.

must be repeated for each of the nbands in the template and once for nbands = 0.

Note:	This command is automatically issued when execution is spawned from within Patran.

The VFCTL file contains information to control the execution of Viewfactor. If no filename is given, a default VFCTL file on your system will be used. This default file may have been altered on your system. The default VFCTL file supplied with Viewfactor is: