He
He provides ideal gas thermodynamic properties for normal helium valid over the temperature range from 50 K to 6000 K based on a constant pressure specific heat of 20.786 J/kmol-K. The reference state for specific enthalpy is 0 at 25 C. The reference state for specific entropy is 0 at 298.15 K and 101.3 kPa
Transport property correlations were also taken from Yaws, Carl L., ed. Chemical Properties Handbook. New York: McGraw-Hill, 1999.
The viscosity correlation is applicable for temperatures between 150 K and 2000 K.
The thermal conductivity is applicable for temperatures between 100 K and 2000 K.
Note that He provides thermodynamic properties assuming ideal gas behavior. Use Helium to provide real fluid properties in the subcooled, saturated mixture, and superheated regimes.