Greetings Anthony,

I vaguely remember seeing a thread where this is discussed in more detail... I'm not sure I found it, but here are a few good references on this topic:

• http://www.cfd-online.com/Forums/ope...naf-model.html
• http://openfoamwiki.net/index.php/Contrib/Janaf
• http://www.openfoam.org/docs/user/thermophysical.php

The last link is for the OpenFOAM documentation, where in the table "JANAF thermodynamics coefficients" it details what values are used from those tables.

Regarding the 15th constant, it's explained on this post: http://www.cfd-online.com/Forums/ope...tml#post326891 post #27
In addition, if you look into the file "etc/thermoData/thermoData", you'll see a variant of the original file "etc/thermoData/therm.dat" reinterpreted to OpenFOAM's dictionary formatting; in this variant file, you'll see that the 15th constant isn't present.

Best regards,
Bruno