The output created by Viewfactor depends on the value of the run control parameter $RUN_CONTROL:. The files VFMSG and VFDIAG are always created (unless a severe error occurs before these files can be opened, which only happens when the file names or directories are invalid). The file VFRAWDAT is created whenever viewfactors are calculated (run control parameter equal 0 or 1). The files VFRESDAT and VFNODEDAT are created whenever Patran Thermal radiation resistors are made (run control parameter equal 0 or 2). The user’s computer system may also create a log file for the batch or background execution of Viewfactor. Viewfactor will also create VFRESTARTSTAT and VFRESTARTDAT files for its own internal use. These two files will automatically be deleted by Viewfactor before execution terminates. However, if execution is terminated abnormally, these files may be left on the disk and you must delete them.

Examples are shown in Reviewing the Viewfactor Output, 103.

This file contains messages from Viewfactor to the user. It begins with a header, followed by the title data from the VFCTL file. Then the control data that was actually used by Viewfactor is echoed to this file. This data may not look quite the same as the user’s VFCTL file. This is because the format may be different and if you allowed any values to default, the default values will be displayed.

The rest of the file contains either informative messages on the progress of the Viewfactor analysis or error messages. Since Viewfactor has been designed to check for many errors and to terminate gracefully on an error condition, the VFMSG file is the only reliable place to find if an error has occurred.

For the most part, Viewfactor will not abort at the computer operating system level. When it detects an error, it reports the error to the VFMSG file and terminates execution without triggering any system level errors. Since there is no system level traceback, the traceback information that Viewfactor outputs to the VFMSG file is very helpful if you need to discuss a problem with MSC’s technical support staff. VFMSG, the Viewfactor Message File, 103 contains a sample VFMSG file.

This file contains primarily numeric diagnostic data. The file begins with the title data from the VFCTL file, followed by any additional title data from the input data files.

If viewfactors were calculated in this analysis, data is given about the sums of the viewfactors from each surface to every other surface in the enclosure. Similar data is also given for the nodal subareas on each surface.

This data is grouped by enclosure. Each group of enclosure data begins with the keyword $ENCL: followed by the enclosure ID number, the number of surfaces in the enclosure, and the number of symmetric images created of this enclosure. Then for each surface in the enclosure there is a line of data containing the surface ID, the sum of the viewfactors from this surface to all other surfaces in the enclosure, 1.0 minus this sum, and the sum of all viewfactors from this surface to other surfaces which were set to zero because they were less than the zero cutoff value ($ZERO:). Following this line will be the sum of the viewfactors for each nodal subarea on the surface. Thus, there will be the same number of data items as there are nodes on the surface. These data will have four values per line until all of the nodes on this surface are used. Currently, none of the element faces supported by Viewfactor have more than four nodes and hence this data fits on one line. This pattern is repeated for each surface in the enclosure.

After all of the surfaces in the enclosure have been accounted for in the above manner, some statistical data for the enclosure is given. This data is presented in five columns. The first line of statistical data is for the surfaces as wholes and the following lines are statistical data for the nodal subareas of the surfaces. The statistical data for the nodal subareas do not have a sound theoretical basis and should not be taken too seriously. It is, however, the best data available at this time.

The five columns contain the following data:

The data for each enclosure is terminated with the $ENDENCL: keyword. If there is more than one enclosure, the above pattern is repeated for each enclosure.

If Patran Thermal radiation resistors were created by this execution of Viewfactor, the VFMSG file will contain information on the radiosity nodes, emissivity resistors, and radiation resistors created for each enclosure.

The file is terminated by the keyword $EOF:.

Examples are given in VFDIAG, the Viewfactor Diagnostic Data File, 106.

This is an unformatted (binary) file containing data about the surfaces and raw viewfactor data. Since it is in binary form, the user may not readily examine its contents. The binary form was chosen because this data file tends to be very large and the binary form is considerably more compact than the text form.

This is also a binary file. It contains data describing the Patran Thermal radiation resistors. This file is typically very large, hence its binary form. Patran Thermal can translate the binary form of this file to a text form which the user can read, but it can be a very large file. The procedure for doing this is described in Interface From Viewfactor to Patran Thermal, 111.

This file must be referenced by the Patran Thermal QINDAT file in order for it to be included in the QTRAN thermal analysis. See Interface From Viewfactor to Patran Thermal, 111.

This file contains the information needed by Patran Thermal to define the additional radiosity nodes created by Viewfactor for the thermal analysis of the thermal radiation interchange. It contains comment lines which begin with a semicolon. If any radiosity nodes were created, the file will contain the line

for the nodes created by Viewfactor. If no radiosity nodes were created by Viewfactor (all surfaces were black) then the file will contain the comment

;NO ADDITIONAL RADIOSITY NODES WERE GENERATED.

This file must be referenced by the Patran Thermal QINDAT file in order for it to be included in the QTRAN thermal analysis. See Interface From Viewfactor to Patran Thermal, 111.