Viewfactor > Data File Specifications > 9.3 VFRAWDAT (Raw Viewfactor Data)
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9.3 VFRAWDAT (Raw Viewfactor Data)
The VFRAWDAT file is a FORTRAN Unformatted Sequential Access file. Since this is an unformatted file, its specific content is machine dependent and so we will only give an informal specification of its form. Each item in curly braces corresponds to a record in the file.
 
Parameter
Description
Nchar
Integer number of characters in the following character string, less than 132.
Comment_String
Character string beginning with the blank character or the * character.
Title_String
Character string beginning with the characters $TITLE: and followed by optional title characters. Maximum length is 80 characters.
Size_String
Character string beginning with the characters $SIZE: and containing the following data in the (A6,4X,4I10) format: Dimension_Code, Number_Nodes, Number_Enclosures, and Max_Node_ID.
 
Dimension_Code
Integer code for the dimensionality of the model.
2 ==> 2-D XY space
-2 ==> 2-D RZ axisymmetric space
3 ==> 3-D XYZ space
 
Number_Nodes - Integer number of nodes in one symmetric image of the model.
 
Number_Enclosure - Integer number of enclosures in the model, before symmetry operations.
 
Max_Node_ID - Integer largest node ID in the model.
Symmetry_String
Character string beginning with the characters $SYM: and followed by the data, Number_Symmetry_Objects, and formatted as (A5,5X,I10).
 
Number_Symmetry_Objects - Integer number of symmetry operations for which data will follow.
Symmetry_Data
15 real constants, unformatted, representing the symmetry operation. See the specification for the VFINDAT file for a description of this data. The data is given in column order.
antisymmetric_
String
Character string containing the characters $ENDSYM:
Begin_Node_Data
String
Character string beginning with the characters $NODES: and followed by the data, Number_Nodes and Symmetry_Multiplier, and formatted as (A7,3X,2I10).
 
Symmetry_Multiplier - Integer giving the total number of images of the model after all symmetry operations have been completed, includes the original image.
Node_Data_Record
(Node_ID)(XYZ_Coordinates).
 
Node_ID - Integer node ID number.
 
XYZ_Coordinates - 3 real constants giving the X, Y, and Z coordinates of the node. For 2-D models, the third number should be zero. For 2D RZ axisymmetric models, the first two coordinates are the R and Z coordinates, respectively.
End_Node_Data_
String
Character string containing the characters $ENDNODES.
Begin_Enclosure_
String
Character string containing the characters $ENCL: and followed by the data, Enclosure_ID, Number_Surfaces, and Symmetry_Multiplier, and formatted as (A6,4X,3I10).
 
Enclosure_ID - Integer ID of this enclosure.
 
Number_Surfaces - Integer number of surfaces in this enclosure.
Number_User_ID
Integer number of User IDs, or UIDs, which are used in this enclosure and which will follow.
User_ID
Integer user ID which is used in this enclosure.
Surface_Data
(SURATT)(SURDAT)(SURNOD)(SURARA)(LFTHND).
 
SURATT - 14 Integers, see the description of surface attributes in the VFINDAT file specification.
 
SURDAT - SURATT number four reals, see the description of surface data in the VFINDAT file specification.
 
SURDAT - SURATT number four reals, see the description of surface data in the VFINDAT file specification.
 
SURNOD - SURATT number five integers giving the nodes on this surface and in the order specified for the corresponding Patran Plus elements.
 
SURARA - SURATT number five plus one reals giving the surface area and the nodal subareas for this surface.
 
LFTHND - Logical, true is surface has left handed orientation.
Surface_Pair_
Record
(Surface_E_Index)(Surface_F_Index)(Symmetry_Index) (Subdivision_Index)(Number_Subdivision)(Can_See_Flag)
 
Surface_E_Index - Integer index to the first surface in the pair.
 
Surface_F_Index - Integer index to the second surface in the pair.
 
Symmetry_Index - Integer index to the symmetric image of the second surface.
 
Subdivision_Index - Integer index to the surface subdivision, not currently used.
 
Number_Subdivision - Integer number of subdivisions of the surface, not currently used.
 
Can_See_Flag - Logical, set true if View_Factor_Data is to follow.
If_Can_See
Not a formal item in the VFRAWDAT file. It is used to indicate the number of View_Factor_Data records that should follow. If_Can_See is set to one if Can_See_Flag is true and set to zero otherwise.
View_Factor_Data
[
(Nodal_Can_See)(Nodal_View_Factor).
(Nodal_Mean_Beam_Length).
]*Number_Nodes_Surface_E.
]*Number_Nodes_Surface_F.
 
Nodal_Can_See - Logical that node on surface E can see node on surface F.
 
Nodal_View_Factor - Real value of the viewfactor from nodal subarea on surface E to nodal subarea on surface F.
 
Nodal_Mean_Beam_Length - Real value of the mean beam length from nodal subarea on surface E to nodal subarea on surface F.
 
Number_Nodes_Surface_E - SURATT number five for surface E.
 
Number_Nodes_Surface_F - SURATT number five for surface F.
Upper_Number_
Surfaces
Number_Surfaces minus the current outer repeat structure index minus one. This provides the upper triangular portion of the surface pair matrix as the part for which the VFRAWDAT file contains data.
Sum_View_Factor_
Data
(SUMSUR)(SUMONE)(SUMZRO)(SUMNOD).
SUMSUR - Real value containing the sum of the viewfactors from this surface to all other surfaces in this enclosure.
SUMONE - Real value equal to one minus SUMSUR.
SUMZRO - Real value containing the sum of all viewfactors from this surface to all other surfaces which were set to zero by virtue of being less than the zero cutoff value.
SUMNOD 7- [Real value containing the sum of the viewfactors from this nodal subarea on surface E to all other nodal subareas on all other surfaces in this enclosure]*. Number_Nodes_Surface_E.
End_Enclosure_
String
Character string containing the characters $ENDENCL:
End_File_String
Character string containing the characters $EOF:
EOF
FORTRAN ENDFILE marker.
Character
FORTRAN CHARACTER*(*) Type with length less than 132 characters.
Logical
FORTRAN default LOGICAL Type.
Integer
FORTRAN default INTEGER Type.
Real
FORTRAN default REAL Type.