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

NameDescription
cp_TCompute specific heat capacity at constant pressure from temperature and gas data
cp_TlowCompute specific heat capacity at constant pressure, low T region
cp_Tlow_derCompute specific heat capacity at constant pressure, low T region
dynamicViscosityLowPressureDynamic viscosity of low pressure gases
h_TCompute specific enthalpy from temperature and gas data; reference is decided by the refChoice input, or by the referenceChoice package constant by default
h_T_derDerivative function for h_T
h_TlowCompute specific enthalpy, low T region; reference is decided by the refChoice input, or by the referenceChoice package constant by default
h_Tlow_derCompute specific enthalpy, low T region; reference is decided by the refChoice input, or by the referenceChoice package constant by default
s0_TCompute specific entropy from temperature and gas data
s0_TlowCompute specific entropy, low T region
s0_Tlow_derCompute derivative of specific entropy, low T region
thermalConductivityEstimateThermal conductivity of polyatomic gases (Eucken and Modified Eucken correlation)

Package Constants

TypeNameValueDescription
BooleanexcludeEnthalpyOfFormationtrueIf true, enthalpy of formation Hf is not included in specific enthalpy h
SpecificEnthalpyh_offset0User defined offset for reference enthalpy, if referenceChoice = UserDefined
IntegermethodForThermalConductivity1 
ReferenceEnthalpyreferenceChoiceModelica.​Media.​Interfaces.​Choices.​ReferenceEnthalpy.​ZeroAt0KChoice 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

TypeNameDescription
DataRecorddataIdeal gas data
TemperatureTTemperature

Outputs

TypeNameDescription
SpecificHeatCapacitycpSpecific 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

TypeNameDescription
DataRecorddataIdeal gas data
TemperatureTTemperature

Outputs

TypeNameDescription
SpecificHeatCapacitycpSpecific 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

TypeNameDescription
DataRecorddataIdeal gas data
TemperatureTTemperature
RealdTTemperature derivative

Outputs

TypeNameDescription
Realcp_derDerivative 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

TypeNameDescription
DataRecorddataIdeal gas data
TemperatureTTemperature
BooleanexclEnthFormIf true, enthalpy of formation Hf is not included in specific enthalpy h
ReferenceEnthalpyrefChoiceChoice of reference enthalpy
SpecificEnthalpyh_offUser defined offset for reference enthalpy, if referenceChoice = UserDefined

Outputs

TypeNameDescription
SpecificEnthalpyhSpecific 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

TypeNameDescription
DataRecorddataIdeal gas data
TemperatureTTemperature
BooleanexclEnthFormIf true, enthalpy of formation Hf is not included in specific enthalpy h
ReferenceEnthalpyrefChoiceChoice of reference enthalpy
SpecificEnthalpyh_offUser defined offset for reference enthalpy, if referenceChoice = UserDefined
RealdTTemperature derivative

Outputs

TypeNameDescription
Realh_derSpecific 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

TypeNameDescription
DataRecorddataIdeal gas data
TemperatureTTemperature
BooleanexclEnthFormIf true, enthalpy of formation Hf is not included in specific enthalpy h
ReferenceEnthalpyrefChoiceChoice of reference enthalpy
SpecificEnthalpyh_offUser defined offset for reference enthalpy, if referenceChoice = UserDefined

Outputs

TypeNameDescription
SpecificEnthalpyhSpecific 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

TypeNameDescription
DataRecorddataIdeal gas data
TemperatureTTemperature
BooleanexclEnthFormIf true, enthalpy of formation Hf is not included in specific enthalpy h
ReferenceEnthalpyrefChoiceChoice of reference enthalpy
SpecificEnthalpyh_offUser defined offset for reference enthalpy, if referenceChoice = UserDefined
RealdTTemperature derivative

Outputs

TypeNameDescription
Realh_derDerivative 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

TypeNameDescription
DataRecorddataIdeal gas data
TemperatureTTemperature

Outputs

TypeNameDescription
SpecificEntropysSpecific 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

TypeNameDescription
DataRecorddataIdeal gas data
TemperatureTTemperature

Outputs

TypeNameDescription
SpecificEntropysSpecific 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

TypeNameDescription
DataRecorddataIdeal gas data
TemperatureTTemperature
RealT_derTemperature derivative

Outputs

TypeNameDescription
SpecificEntropysSpecific 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:

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

TypeNameDescription
Temp_KTGas temperature
Temp_KTcCritical temperature of gas
MolarMassMMolar mass of gas
MolarVolumeVcCritical molar volume of gas
RealwAcentric factor of gas
DipoleMomentmuDipole moment of gas molecule
RealkSpecial correction for highly polar substances

Outputs

TypeNameDescription
DynamicViscosityetaDynamic 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

TypeNameDescription
SpecificHeatCapacityCpConstant pressure heat capacity
DynamicViscosityetaDynamic viscosity
Integermethod1: Eucken Method, 2: Modified Eucken Method
DataRecorddataIdeal gas data

Outputs

TypeNameDescription
ThermalConductivitylambdaThermal conductivity [W/(m.k)]

Generated 2018-12-12 12:13:53 EST by MapleSim.