Last Updated: 12/13/04
If you click on
the link below, a Microsoft
Excel workbook will be downloaded to your computer.
Each of the worksheets making up this workbook
will compute the radiation viewfactor for a particular
geometry using the inputs you supply. In addition, each worksheet
draws your geometry
to scale so that you can verify your inputs
and also appreciate the numerical
values of the computed values returned.
The four geometries covered
in this workbook are those
that are usually
presented in graphical form in textbooks.
This workbook was
written under Windows, but should
work under MS Office running on a Macintosh. Earlier versions of MS Office
on both platforms may not support all features used in this workbook.
Disclaimer No warranties, expressed or implied, are made that this program
is free from error, or is consistent with any particular standard of
merchantability,
or will meet your requirements for any particular application. This program
should not be relied on for solving problems
whose incorrect solution could
result in injury or lost property. If
you use this program in such a manner,
it is at own risk. The author disclaims all liability for direct or consequential
damages resulting from your use of this program, i.e., SOFTWARE THAT IS
FREE HAS NO GUARANTEE!
This Excel workbook contain several macros written in Visual Basic for Applications, so that when you open it you will probably see a warning like, "[filename] contains macros. Macros may contain viruses. It is always safe to disable macros, but if the macros are legitimate, you might lose some functionality." Then you are given the choices: "Disable Macros", "Enable Macros" and "More Info". In the case of this spreadsheet, you must select "Enable Macros" or it will not work at all! (If you not even offered this choice, then your security is probably set at "High." You must have your security level in Excel set at "Medium," which allows you to "choose whether or not to run potentially unsafe macros.") My virus checker is set to update automatically every day (yours should be too!). You might scan these materials (and anything else containing macros you might download from the Internet) before opening them, but then you MUST enable macros!
Radiation View Factors - Perpendicular Plates
The first of the four worksheets finds the viewfactor for perpendicular plates with a common edge (from the well-known analytical solution) and draws an isometric view of them on the screen. The user inputs the length of the common edge as well as the second dimension of the two plates. This worksheet and the one for parallel plates was developed in part to help in verifying the viewfactor values computed by our much more versatile Visual Basic viewfactor module.
Radiation View Factors - Coaxial Disks
The viewfactor for coaxial, parallel disks is computed from the analytical solution and then they are drawn to scale on the screen. The user inputs the radii of the two disks (emitter and receiver) and the separation distance.
Radiation View Factors - Coaxial Cylinders
Viewfactors for finite-length, coaxial cylinders are computed using a combination of analytical solutions and viewfactor algebra. The user inputs the radii of the two cylinders and their length. All nine relevent viewfactors and a scale drawing are returned.
Radiation View Factors - Parallel Rectangles
