Cp/R = a1 + a2 T + a3 T^2 + a4 T^3 + a5 T^4
H/RT = a1 + a2 T /2 + a3 T^2 /3 + a4 T^3 /4 + a5 T^4 /5 + a6/T
S/RT = a1 lnT + a2 T + a3 T^2 /2 + a4 T^3 /3 + a5 T^4 /4 + a7
where a1, a2, a3, a4, a5, a6, and a7 are the numerical coefficients supplied in
NASA thermodynamic files. The
first 7 numbers starting on the second line of each species entry (five of the
second line and the first two of the third line) are the seven coefficients (a1
through a7, respectively) for the high-temperature range (above 1000 K, the upper
boundary is specified on the first line of the species entry). The following
seven numbers are the coefficients (a1 through a7, respectively) for the
low-temperature range (below 1000 K, the lower boundary is specified on the first
line of the species entry).H in the above equation is defined as
H(T) = Hf(298) + [ H(T) - H(298) ]
so that, in general, H(T) is not equal to Hf(T) and one needs to have the
data for the reference elements to calculate Hf(T).
|See GRI-Mech thermodynamic values|
Chemkin you may get output that is
significantly different.