CH4
CH4 provides ideal gas thermodynamic properties valid for methane over the temperature range from 250 K to 6000 K based on the property information from McBride et al. (2002). The reference state for specific enthalpy is based on the enthalpy of formation relative to the elements (-74,595 kJ/kmol) at 25 C. The reference state for specific enthalpy is based on the enthalpy of formation relative to the elements at 25 C. The reference state for specific entropy is based on the Third Law of Thermodynamics. The reference values are from:
Bonnie J. McBride, Michael J. Zehe, and Sanford Gordon
"NASA Glenn Coefficients for Calculating Thermodynamic Properties of Individual Species"
NASA/TP-2002-211556, Sept. 2002
https://www.grc.nasa.gov/WWW/CEAWeb/
Transport property correlations are implemented using data from provided by N.B. Vargaftik, Y.K. Vinogradov, V.S. Yargin, V.S., Handbook of Physical Properties of Liquids and Gases, 3rd ed, 1996, ISBN 1-56700-063-0. The viscosity correlation is applicable for temperatures between 200 K and 1200 K. The thermal conductivity correlation is applicable for temperatures between 200 K and 1270 K.
Note that CH4 provides thermodynamic properties assuming ideal gas behavior. Use METHANE to provide real fluid properties in the subcooled, saturated mixture, and superheated regimes.