Ideal Gas Law

Defines an ideal gas, for example:

EOS GAS
  DENSITY IDEAL
  ENTHALPY IDEAL_CO2
  VISCOSITY CONSTANT 0.03 cP
END

The enthalpy of the ideal gas can defined specified as IDEAL_METHANE, or IDEAL_CO2. This value cannot be defaulted for thermal problems or the code will return an error.

Viscosity units are optional, if not entered defaults to \(Pa.s\)

The density is modeled with the gas ideal law.

\[\rho( P , T )= \frac{P}{RT},\]

where:

\[R = 8.31446,\]

the gas ideal constant, units \(J/(\mbox{mol} K)\).

The Enthalpy will be computed differently based on the type of ideal gas selected above.

For IDEAL_METHANE the Enthalpy will be computed as:

\[h(T )=c_p T,\]

where

\[c_p = 35.69,\]

the constant pressure heat capacity of methane, units J/(mol K), at T = 288.15 K, P=1 bar.

For IDEAL_CO2 the Enthalpy will be computed as:

\[h(T )=c_v T +RT,\]

where:

\[c_v = 28.075,\]

the constant volume heat capacity of CO₂, units \(J/(\mbox{mol} K)\), at T = 15 C and P= 1 atm.