Package Modelica.Media.IdealGases.Common.Functions
Basic Functions for ideal gases: cp, h, s, thermal conductivity, viscosity

Information

Standard package icon.

Extends from Modelica.Icons.FunctionsPackage (Icon for packages containing functions).

Package Contents

Name	Description
`cp_T`	Compute specific heat capacity at constant pressure from temperature and gas data
`cp_Tlow`	Compute specific heat capacity at constant pressure, low T region
`cp_Tlow_der`	Compute specific heat capacity at constant pressure, low T region
`dynamicViscosityLowPressure`	Dynamic viscosity of low pressure gases
`h_T`	Compute specific enthalpy from temperature and gas data; reference is decided by the refChoice input, or by the referenceChoice package constant by default
`h_T_der`	Derivative function for h_T
`h_Tlow`	Compute specific enthalpy, low T region; reference is decided by the refChoice input, or by the referenceChoice package constant by default
`h_Tlow_der`	Compute specific enthalpy, low T region; reference is decided by the refChoice input, or by the referenceChoice package constant by default
`s0_T`	Compute specific entropy from temperature and gas data
`s0_Tlow`	Compute specific entropy, low T region
`s0_Tlow_der`	Compute derivative of specific entropy, low T region
`thermalConductivityEstimate`	Thermal conductivity of polyatomic gases (Eucken and Modified Eucken correlation)

Package Constants

Type	Name	Value	Description
`Boolean`	`excludeEnthalpyOfFormation`	`true`	If true, enthalpy of formation Hf is not included in specific enthalpy h
`SpecificEnthalpy`	`h_offset`	`0`	User defined offset for reference enthalpy, if referenceChoice = UserDefined
`Integer`	`methodForThermalConductivity`	`1`
`ReferenceEnthalpy`	`referenceChoice`	`Modelica.Media.Interfaces.Choices.ReferenceEnthalpy.ZeroAt0K`	Choice of reference enthalpy

Function Modelica.Media.IdealGases.Common.Functions.cp_T
Compute specific heat capacity at constant pressure from temperature and gas data

Information

This icon indicates Modelica functions.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`DataRecord`	`data`	Ideal gas data
`Temperature`	`T`	Temperature

Outputs

Type	Name	Description
`SpecificHeatCapacity`	`cp`	Specific heat capacity at temperature T

Function Modelica.Media.IdealGases.Common.Functions.cp_Tlow
Compute specific heat capacity at constant pressure, low T region

Information

This icon indicates Modelica functions.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`DataRecord`	`data`	Ideal gas data
`Temperature`	`T`	Temperature

Outputs

Type	Name	Description
`SpecificHeatCapacity`	`cp`	Specific heat capacity at temperature T

Function Modelica.Media.IdealGases.Common.Functions.cp_Tlow_der
Compute specific heat capacity at constant pressure, low T region

Information

This icon indicates Modelica functions.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`DataRecord`	`data`	Ideal gas data
`Temperature`	`T`	Temperature
`Real`	`dT`	Temperature derivative

Outputs

Type	Name	Description
`Real`	`cp_der`	Derivative of specific heat capacity

Function Modelica.Media.IdealGases.Common.Functions.h_T
Compute specific enthalpy from temperature and gas data; reference is decided by the refChoice input, or by the referenceChoice package constant by default

Information

This icon indicates Modelica functions.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`DataRecord`	`data`	Ideal gas data
`Temperature`	`T`	Temperature
`Boolean`	`exclEnthForm`	If true, enthalpy of formation Hf is not included in specific enthalpy h
`ReferenceEnthalpy`	`refChoice`	Choice of reference enthalpy
`SpecificEnthalpy`	`h_off`	User defined offset for reference enthalpy, if referenceChoice = UserDefined

Outputs

Type	Name	Description
`SpecificEnthalpy`	`h`	Specific enthalpy at temperature T

Function Modelica.Media.IdealGases.Common.Functions.h_T_der
Derivative function for h_T

Information

This icon indicates Modelica functions.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`DataRecord`	`data`	Ideal gas data
`Temperature`	`T`	Temperature
`Boolean`	`exclEnthForm`	If true, enthalpy of formation Hf is not included in specific enthalpy h
`ReferenceEnthalpy`	`refChoice`	Choice of reference enthalpy
`SpecificEnthalpy`	`h_off`	User defined offset for reference enthalpy, if referenceChoice = UserDefined
`Real`	`dT`	Temperature derivative

Outputs

Type	Name	Description
`Real`	`h_der`	Specific enthalpy at temperature T

Function Modelica.Media.IdealGases.Common.Functions.h_Tlow
Compute specific enthalpy, low T region; reference is decided by the refChoice input, or by the referenceChoice package constant by default

Information

This icon indicates Modelica functions.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`DataRecord`	`data`	Ideal gas data
`Temperature`	`T`	Temperature
`Boolean`	`exclEnthForm`	If true, enthalpy of formation Hf is not included in specific enthalpy h
`ReferenceEnthalpy`	`refChoice`	Choice of reference enthalpy
`SpecificEnthalpy`	`h_off`	User defined offset for reference enthalpy, if referenceChoice = UserDefined

Outputs

Type	Name	Description
`SpecificEnthalpy`	`h`	Specific enthalpy at temperature T

Function Modelica.Media.IdealGases.Common.Functions.h_Tlow_der
Compute specific enthalpy, low T region; reference is decided by the refChoice input, or by the referenceChoice package constant by default

Information

This icon indicates Modelica functions.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`DataRecord`	`data`	Ideal gas data
`Temperature`	`T`	Temperature
`Boolean`	`exclEnthForm`	If true, enthalpy of formation Hf is not included in specific enthalpy h
`ReferenceEnthalpy`	`refChoice`	Choice of reference enthalpy
`SpecificEnthalpy`	`h_off`	User defined offset for reference enthalpy, if referenceChoice = UserDefined
`Real`	`dT`	Temperature derivative

Outputs

Type	Name	Description
`Real`	`h_der`	Derivative of specific enthalpy at temperature T

Function Modelica.Media.IdealGases.Common.Functions.s0_T
Compute specific entropy from temperature and gas data

Information

This icon indicates Modelica functions.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`DataRecord`	`data`	Ideal gas data
`Temperature`	`T`	Temperature

Outputs

Type	Name	Description
`SpecificEntropy`	`s`	Specific entropy at temperature T

Function Modelica.Media.IdealGases.Common.Functions.s0_Tlow
Compute specific entropy, low T region

Information

This icon indicates Modelica functions.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`DataRecord`	`data`	Ideal gas data
`Temperature`	`T`	Temperature

Outputs

Type	Name	Description
`SpecificEntropy`	`s`	Specific entropy at temperature T

Function Modelica.Media.IdealGases.Common.Functions.s0_Tlow_der
Compute derivative of specific entropy, low T region

Information

This icon indicates Modelica functions.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`DataRecord`	`data`	Ideal gas data
`Temperature`	`T`	Temperature
`Real`	`T_der`	Temperature derivative

Outputs

Type	Name	Description
`Real`	`s_der`	Derivative of specific entropy at temperature T

Function Modelica.Media.IdealGases.Common.Functions.dynamicViscosityLowPressure
Dynamic viscosity of low pressure gases

Information

The used formula are based on the method of Chung et al (1984, 1988) referred to in ref [1] chapter 9. The formula 9-4.10 is the one being used. The Formula is given in non-SI units, the following conversion constants were used to transform the formula to SI units:

Const1_SI: The factor 10^(-9.5) =10^(-2.5)*1e-7 where the factor 10^(-2.5) originates from the conversion of g/mol->kg/mol + cm^3/mol->m^3/mol and the factor 1e-7 is due to conversion from microPoise->Pa.s.
Const2_SI: The factor 1/3.335641e-27 = 1e-3/3.335641e-30 where the factor 3.335641e-30 comes from debye->C.m and 1e-3 is due to conversion from cm^3/mol->m^3/mol

References:

[1] Bruce E. Poling, John E. Prausnitz, John P. O'Connell, "The Properties of Gases and Liquids" 5th Ed. Mc Graw Hill.

Author

T. Skoglund, Lund, Sweden, 2004-08-31

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`Temp_K`	`T`	Gas temperature
`Temp_K`	`Tc`	Critical temperature of gas
`MolarMass`	`M`	Molar mass of gas
`MolarVolume`	`Vc`	Critical molar volume of gas
`Real`	`w`	Acentric factor of gas
`DipoleMoment`	`mu`	Dipole moment of gas molecule
`Real`	`k`	Special correction for highly polar substances

Outputs

Type	Name	Description
`DynamicViscosity`	`eta`	Dynamic viscosity of gas

Function Modelica.Media.IdealGases.Common.Functions.thermalConductivityEstimate
Thermal conductivity of polyatomic gases (Eucken and Modified Eucken correlation)

Information

This function provides two similar methods for estimating the thermal conductivity of polyatomic gases. The Eucken method (input method == 1) gives good results for low temperatures, but it tends to give an underestimated value of the thermal conductivity (lambda) at higher temperatures.
The Modified Eucken method (input method == 2) gives good results for high-temperatures, but it tends to give an overestimated value of the thermal conductivity (lambda) at low temperatures.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
`SpecificHeatCapacity`	`Cp`	Constant pressure heat capacity
`DynamicViscosity`	`eta`	Dynamic viscosity
`Integer`	`method`	1: Eucken Method, 2: Modified Eucken Method
`DataRecord`	`data`	Ideal gas data

Outputs

Type	Name	Description
`ThermalConductivity`	`lambda`	Thermal conductivity [W/(m.k)]

Package Modelica.​Media.​IdealGases.​Common.​FunctionsBasic Functions for ideal gases: cp, h, s, thermal conductivity, viscosity

Information

Package Contents

Package Constants

Function Modelica.​Media.​IdealGases.​Common.​Functions.​cp_TCompute specific heat capacity at constant pressure from temperature and gas data

Information

Inputs

Outputs

Function Modelica.​Media.​IdealGases.​Common.​Functions.​cp_TlowCompute specific heat capacity at constant pressure, low T region

Information

Inputs

Outputs

Function Modelica.​Media.​IdealGases.​Common.​Functions.​cp_Tlow_derCompute specific heat capacity at constant pressure, low T region

Information

Inputs

Outputs

Function Modelica.​Media.​IdealGases.​Common.​Functions.​h_TCompute specific enthalpy from temperature and gas data; reference is decided by the refChoice input, or by the referenceChoice package constant by default

Information

Inputs

Outputs

Function Modelica.​Media.​IdealGases.​Common.​Functions.​h_T_derDerivative function for h_T

Information

Inputs

Outputs

Function Modelica.​Media.​IdealGases.​Common.​Functions.​h_TlowCompute specific enthalpy, low T region; reference is decided by the refChoice input, or by the referenceChoice package constant by default

Information

Inputs

Outputs

Function Modelica.​Media.​IdealGases.​Common.​Functions.​h_Tlow_derCompute specific enthalpy, low T region; reference is decided by the refChoice input, or by the referenceChoice package constant by default

Information

Inputs

Outputs

Function Modelica.​Media.​IdealGases.​Common.​Functions.​s0_TCompute specific entropy from temperature and gas data

Information

Inputs

Outputs

Function Modelica.​Media.​IdealGases.​Common.​Functions.​s0_TlowCompute specific entropy, low T region

Information

Inputs

Outputs

Function Modelica.​Media.​IdealGases.​Common.​Functions.​s0_Tlow_derCompute derivative of specific entropy, low T region

Information

Inputs

Outputs

Function Modelica.​Media.​IdealGases.​Common.​Functions.​dynamicViscosityLowPressureDynamic viscosity of low pressure gases

Information

References:

Author

Inputs

Outputs

Function Modelica.​Media.​IdealGases.​Common.​Functions.​thermalConductivityEstimateThermal conductivity of polyatomic gases (Eucken and Modified Eucken correlation)

Information

Inputs

Outputs

Package Modelica.Media.IdealGases.Common.Functions
Basic Functions for ideal gases: cp, h, s, thermal conductivity, viscosity

Function Modelica.Media.IdealGases.Common.Functions.cp_T
Compute specific heat capacity at constant pressure from temperature and gas data

Function Modelica.Media.IdealGases.Common.Functions.cp_Tlow
Compute specific heat capacity at constant pressure, low T region

Function Modelica.Media.IdealGases.Common.Functions.cp_Tlow_der
Compute specific heat capacity at constant pressure, low T region

Function Modelica.Media.IdealGases.Common.Functions.h_T
Compute specific enthalpy from temperature and gas data; reference is decided by the refChoice input, or by the referenceChoice package constant by default

Function Modelica.Media.IdealGases.Common.Functions.h_T_der
Derivative function for h_T

Function Modelica.Media.IdealGases.Common.Functions.h_Tlow
Compute specific enthalpy, low T region; reference is decided by the refChoice input, or by the referenceChoice package constant by default

Function Modelica.Media.IdealGases.Common.Functions.h_Tlow_der
Compute specific enthalpy, low T region; reference is decided by the refChoice input, or by the referenceChoice package constant by default

Function Modelica.Media.IdealGases.Common.Functions.s0_T
Compute specific entropy from temperature and gas data

Function Modelica.Media.IdealGases.Common.Functions.s0_Tlow
Compute specific entropy, low T region

Function Modelica.Media.IdealGases.Common.Functions.s0_Tlow_der
Compute derivative of specific entropy, low T region

Function Modelica.Media.IdealGases.Common.Functions.dynamicViscosityLowPressure
Dynamic viscosity of low pressure gases

Function Modelica.Media.IdealGases.Common.Functions.thermalConductivityEstimate
Thermal conductivity of polyatomic gases (Eucken and Modified Eucken correlation)