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EOS

Defines an equation of state for a simulated fluid.

Required Cards:

EOS <string>

Specifies the fluid for which the EOS applies [WATER, GAS].

Optional Cards:

WATER Phase

DENSITY <string> <optional parameters>

DENSITY CONSTANT <float>

Units of density should be in kg/m^3.

DENSITY EXPONENTIAL <float> <float> <float> (ref. density [rho0], ref. pressure [p0], compressibility)

Exponential function: rho0 * exp(compressibility*(pressure - p0))

DENSITY IF97

Liquid water density EOS based on International Association for the Properties of Water and Steam Standard IF97

STEAM_DENSITY IF97

Superheated vapor density EOS based on International Association for the Properties of Water and Steam Standard IF97

DENSITY DEFAULT

Default water EOS based on International Formulation Committee of the Sixth International Conference on Properties of Steam (1967). Density is calculated as a function of temperature and pressure.

ENTHALPY <string> <optional parameters>

ENTHALPY CONSTANT <float>

Units of enthalpy should be in J/kmol.

ENTHALPY IF97

Liquid water enthalpy EOS based on International Association for the Properties of Water and Steam Standard IF97

STEAM_ENTHALPY IF97

Superheated vapor enthalpy EOS based on International Association for the Properties of Water and Steam Standard IF97

ENTHALPY DEFAULT

Default water EOS based on International Formulation Committee of the Sixth International Conference on Properties of Steam (1967). Enthalpy is calculated as a function of temperature and pressure.

VISCOSITY <string> <optional parameters>

VISCOSITY CONSTANT <float>

Units of viscosity should be in Pa-s (dynamic viscosity).

VISCOSITY DEFAULT

Default water EOS based on International Formulation Committee of the Sixth International Conference on Properties of Steam (1967). Viscosity is calculated as a function of temperature, pressure, and saturation pressure.

TEST <float> <float> <float> <float> <int> <int> <string> <string>

Tests the equation of state (currently water density only). The order of the arguments are temperature low [C], temperature high [C], pressure low [Pa], pressure high [Pa], number of temperatures, number of pressures, temperature distribution [uniform,log], pressure distribution [uniform,log]

GAS Phase

DENSITY <string> <optional parameters>

DENSITY CONSTANT <float>

Units of density should be in kmol/m^3.

DENSITY IDEAL

Calculate the gas density using the ideal gas law.

DENSITY DEFAULT

Calculate the gas density using the ideal gas law.

DENSITY RKS

Calculate the gas density using the Redlich-Kwong-Soave (RKS) equation of state. Currently, the gas is assumed to behave as a single-component gas (mixture properties are not supported). If none of the following optional subcards are specified, default values for hydrogen gas are employed. Either the long or short keywords can be input.

HYDROGEN | NON-HYDROGEN

Use a hydrogen-specific, modified correlation (Graboski) to calculate the alpha parameter.

CRITICAL_TEMPERATURE, TC <float>

Units kelvin.

CRITICAL_PRESSURE, PC <float>

Units Pa.

ACENTRIC_FACTOR, AC <float>

OMEGAA, A <float>

OMEGAB, B <float>

ENTHALPY <string> <optional parameters>

ENTHALPY CONSTANT <float>

Units of enthalpy should be in J/kmol.

ENTHALPY IDEAL

Calculate enthalpy using the ideal gas law.

ENTHALPY DEFAULT

Calculate enthalpy using the ideal gas law.

VISCOSITY <string> <optional parameters>

VISCOSITY CONSTANT <float>

Units of viscosity should be in Pa-s (dynamic viscosity).

VISCOSITY DEFAULT

Calculate gas viscosity using correlations for water-vapor/air mixutures (Hirschfelder et al.) Viscosity is calculated as a function of temperature, pressure, and saturation pressure.

HENRYS_CONSTANT <string> <optional parameters>

HENRYS_CONSTANT is currently only used in GENERAL mode.

HENRYS_CONSTANT CONSTANT <float>

Set Henry’s constant (the solubility of gas in liquid) to a fixed value. The units for Henry’s constant are [Pa].

HENRYS_CONSTANT DEFAULT

Calculate Henry’s constant using correlations for water-vapor/air mixutures (Fernandez-Prini et al.). Henry’s constant is calculated as a function of temperature and saturation pressure.

FORMULA_WEIGHT <float>

Set the molecular weight for the gas component. Units g/mol.

TEST <float> <float> <float> <float> <int> <int> <string> <string>

Tests the equation of state (currently gas density only). The order of the arguments are temperature low [C], temperature high [C], pressure low [Pa], pressure high [Pa], number of temperatures, number of pressures, temperature distribution [uniform,log], pressure distribution [uniform,log]

Examples

EOS WATER
  DENSITY EXPONENTIAL 997.16d0 101325.d0 1.d-8
  VISCOSITY CONSTANT 8.904156d-4
END

EOS WATER
  DENSITY CONSTANT 997.16d0 kg/m^3
  ENTHALPY CONSTANT 1.8890d0 J/kmol
  VISCOSITY CONSTANT 8.904156d-4 Pa-s
  TEST 1.d-2 500.d0 1.d-2 5.d8 100 100 uniform uniform
END

EOS GAS
  DENSITY IDEAL
  VISCOSITY CONSTANT 9.0829d-6
  HENRYS_CONSTANT CONSTANT 1.d10
END

EOS GAS
  DENSITY RKS
    HYDROGEN
    TC 41.67
    PC 2.1029d6
    AC 0.00
    A 0.42747
    B 0.08664
  /
  VISCOSITY CONSTANT 9.0829d-6
  FORMULA_WEIGHT 2.01588D0
END