Partial Package Modelica.Media.IdealGases.Common.MixtureGasNasaMedium model of a mixture of ideal gases based on NASA source
Partial Package Modelica.Media.IdealGases.Common.MixtureGasNasa
This model calculates the medium properties for single component ideal gases.
Sources for model and literature:
Original Data: Computer program for calculation of complex chemical
equilibrium compositions and applications. Part 1: Analysis
Document ID: 19950013764 N (95N20180) File Series: NASA Technical Reports
Report Number: NASA-RP-1311 E-8017 NAS 1.61:1311
Authors: Gordon, Sanford (NASA Lewis Research Center)
Mcbride, Bonnie J. (NASA Lewis Research Center)
Published: Oct 01, 1994.
Known limits of validity:
The data is valid for
temperatures between 200 K and 6000 K. A few of the data sets for
monatomic gases have a discontinuous 1st derivative at 1000 K, but
this never caused problems so far.
This model has been copied from the ThermoFluid library. It has been developed by Hubertus Tummescheit.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium (Base class for pure substances of several chemical substances).
| Name | Description |
|---|---|
AbsolutePressure | Type for absolute pressure with medium specific attributes |
BaseProperties | Base properties (p, d, T, h, u, R, MM, X, and Xi of NASA mixture gas |
Basic … | The most basic version of a record used in several degrees of detail |
beta | Alias for isobaricExpansionCoefficient for user convenience |
Choices … | |
CumulativeExtraProperty | Type for conserved integral of unspecified, mass specific property |
Density | Type for density with medium specific attributes |
density | Return density of ideal gas |
density_derh_p | Return density derivative w.r.t. specific enthalpy at constant pressure |
density_derp_h | Return density derivative w.r.t. pressure at const specific enthalpy |
density_derp_T | Return density derivative by pressure at constant temperature |
density_derT_p | Return density derivative by temperature at constant pressure |
density_derX | Return density derivative by mass fraction |
density_phX | Return density from p, h, and X or Xi |
density_psX | Return density from p, s, and X or Xi |
density_pTX | Return density from p, T, and X or Xi |
DerDensityByEnthalpy | Type for partial derivative of density with respect to enthalpy with medium specific attributes |
DerDensityByPressure | Type for partial derivative of density with respect to pressure with medium specific attributes |
DerDensityByTemperature | Type for partial derivative of density with respect to temperature with medium specific attributes |
DerEnthalpyByPressure | Type for partial derivative of enthalpy with respect to pressure with medium specific attributes |
DerTemperatureByPressure | Type for partial derivative of temperature with respect to pressure with medium specific attributes |
DipoleMoment | Type for dipole moment with medium specific attributes |
DynamicViscosity | Type for dynamic viscosity with medium specific attributes |
dynamicViscosity | Return mixture dynamic viscosity |
EnthalpyFlowRate | Type for enthalpy flow rate with medium specific attributes |
ExtraProperty | Type for unspecified, mass-specific property transported by flow |
ExtraPropertyFlowRate | Type for flow rate of unspecified, mass-specific property |
FixedPhase | Phase of the fluid: 1 for 1-phase, 2 for two-phase, 0 for not known, e.g., interactive use |
FluidConstants | |
FluidLimits | Validity limits for fluid model |
gasConstant | Return gasConstant |
gasMixtureViscosity | Return viscosities of gas mixtures at low pressures (Wilke method) |
h_TX | Return specific enthalpy |
h_TX_der | Return specific enthalpy derivative |
heatCapacity_cp | Alias for deprecated name |
heatCapacity_cv | Alias for deprecated name |
IdealGas … | The ideal gas version of a record used in several degrees of detail |
isentropicEnthalpy | Return isentropic enthalpy |
isentropicEnthalpyApproximation | Approximate method of calculating h_is from upstream properties and downstream pressure |
IsentropicExponent | Type for isentropic exponent with medium specific attributes |
isentropicExponent | Return isentropic exponent |
IsobaricExpansionCoefficient | Type for isobaric expansion coefficient with medium specific attributes |
isobaricExpansionCoefficient | Return isobaric expansion coefficient beta |
isothermalCompressibility | Return isothermal compressibility factor |
kappa | Alias of isothermalCompressibility for user convenience |
lowPressureThermalConductivity | Return thermal conductivities of low-pressure gas mixtures (Mason and Saxena Modification) |
MassFlowRate | Type for mass flow rate with medium specific attributes |
MassFraction | Type for mass fraction with medium specific attributes |
massToMoleFractions | Return mole fractions from mass fractions X |
MixEntropy | Return mixing entropy of ideal gases / R |
mixtureViscosityChung | Return the viscosity of gas mixtures without access to component viscosities (Chung, et. al. rules) |
MolarMass | Type for molar mass with medium specific attributes |
molarMass | Return molar mass of mixture |
MolarVolume | Type for molar volume with medium specific attributes |
MoleFraction | Type for mole fraction with medium specific attributes |
moleToMassFractions | Return mass fractions X from mole fractions |
PrandtlNumber | Type for Prandtl number with medium specific attributes |
prandtlNumber | Return the Prandtl number |
pressure | Return pressure of ideal gas |
s_TX | Return temperature dependent part of the entropy, expects full entropy vector |
SaturationProperties | Saturation properties of two phase medium |
setSmoothState | Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b |
setState_dTX | Return thermodynamic state as function of d, T and composition X |
setState_phX | Return thermodynamic state as function of p, h and composition X |
setState_psX | Return thermodynamic state as function of p, s and composition X |
setState_pTX | Return thermodynamic state as function of p, T and composition X |
SpecificEnergy | Type for specific energy with medium specific attributes |
SpecificEnthalpy | Type for specific enthalpy with medium specific attributes |
specificEnthalpy | Return specific enthalpy |
specificEnthalpy_psX | Return specific enthalpy from p, s, and X or Xi |
specificEnthalpy_pTX | Return specific enthalpy from p, T, and X or Xi |
SpecificEntropy | Type for specific entropy with medium specific attributes |
specificEntropy | Return specific entropy |
specificEntropy_pTX | Return specific enthalpy from p, T, and X or Xi |
specificGibbsEnergy | Return specific Gibbs energy |
SpecificHeatCapacity | Type for specific heat capacity with medium specific attributes |
specificHeatCapacityCp | Return specific heat capacity at constant pressure |
specificHeatCapacityCv | Return specific heat capacity at constant volume from temperature and gas data |
specificHelmholtzEnergy | Return specific Helmholtz energy |
SpecificInternalEnergy | Type for specific internal energy with medium specific attributes |
specificInternalEnergy | Return specific internal energy |
SurfaceTension | Type for surface tension with medium specific attributes |
T_hX | Return temperature from specific enthalpy and mass fraction |
T_psX | Return temperature from pressure, specific entropy and mass fraction |
Temperature | Type for temperature with medium specific attributes |
temperature | Return temperature of ideal gas |
temperature_phX | Return temperature from p, h, and X or Xi |
temperature_psX | Return temperature from p,s, and X or Xi |
ThermalConductivity | Type for thermal conductivity with medium specific attributes |
thermalConductivity | Return thermal conductivity for low pressure gas mixtures |
ThermodynamicState | Thermodynamic state variables |
TwoPhase … | The two phase fluid version of a record used in several degrees of detail |
VelocityOfSound | Type for velocity of sound with medium specific attributes |
velocityOfSound | Return velocity of sound |
| Type | Name | Value | Description |
|---|---|---|---|
ExtraProperty | C_default[nC] | fill(0, nC) | Default value for trace substances of medium (for initialization) |
Real | C_nominal[nC] | 1e-6 * ones(nC) | Default for the nominal values for the extra properties |
Boolean | excludeEnthalpyOfFormation | true | If true, enthalpy of formation Hf is not included in specific enthalpy h |
String | extraPropertiesNames[:] | fill("", 0) | Names of the additional (extra) transported properties. Set extraPropertiesNames=fill("",0) if unused |
Boolean | fixedX | false | = true if medium contains the equation X = reference_X |
SpecificEnthalpy | h_default | specificEnthalpy_pTX(p_default, T_default, X_default) | Default value for specific enthalpy of medium (for initialization) |
SpecificEnthalpy | h_offset | 0 | User defined offset for reference enthalpy, if referenceChoice = UserDefined |
String | mediumName | "unusablePartialMedium" | Name of the medium |
Integer | methodForThermalConductivity | 1 | |
MolarMass | MMX[nX] | data[msim/UNKNOWN].MM | Molar masses of components |
final Integer | nC | size(extraPropertiesNames, 1) | Number of extra (outside of standard mass-balance) transported properties |
final Integer | nS | size(substanceNames, 1) | Number of substances |
Integer | nX | nS | Number of mass fractions |
Integer | nXi | if fixedX then 0 else if reducedX then nS - 1 else nS | Number of structurally independent mass fractions (see docu for details) |
AbsolutePressure | p_default | 101325 | Default value for pressure of medium (for initialization) |
Boolean | reducedX | false | = true if medium contains the equation sum(X) = 1.0; set reducedX=true if only one substance (see docu for details) |
AbsolutePressure | reference_p | 101325 | Reference pressure of Medium: default 1 atmosphere |
Temperature | reference_T | 298.15 | Reference temperature of Medium: default 25 deg Celsius |
MassFraction | reference_X[nX] | fill(nX ^ (-1), nX) | Default mass fractions of medium |
ReferenceEnthalpy | referenceChoice | ReferenceEnthalpy.ZeroAt0K | Choice of reference enthalpy |
Boolean | singleState | false | = true, if u and d are not a function of pressure |
String | substanceNames[:] | data[msim/UNKNOWN].name | Names of the mixture substances. Set substanceNames={mediumName} if only one substance. |
Temperature | T_default | Modelica.SIunits.Conversions.from_degC(20) | Default value for temperature of medium (for initialization) |
IndependentVariables | ThermoStates | Modelica.Media.Interfaces.Choices.IndependentVariables.pTX | Enumeration type for independent variables |
MassFraction | X_default[nX] | reference_X | Default value for mass fractions of medium (for initialization) |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.AbsolutePressureExtends from Modelica.SIunits.AbsolutePressure.
| Name | Value |
|---|---|
quantity | "Pressure" |
unit | "Pa" |
displayUnit | "bar" |
min | 0 |
max | 1e+8 |
start | 1000000 |
nominal | 1000000 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.DensityExtends from Modelica.SIunits.Density.
| Name | Value |
|---|---|
quantity | "Density" |
unit | "kg/m3" |
displayUnit | "g/cm3" |
min | 0 |
max | 100000 |
start | 10 |
nominal | 10 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.DynamicViscosityExtends from Modelica.SIunits.DynamicViscosity.
| Name | Value |
|---|---|
quantity | "DynamicViscosity" |
unit | "Pa.s" |
min | 0 |
max | 1e+8 |
start | 0.001 |
nominal | 0.001 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.EnthalpyFlowRateExtends from Modelica.SIunits.EnthalpyFlowRate.
| Name | Value |
|---|---|
quantity | "EnthalpyFlowRate" |
unit | "W" |
min | -1e+8 |
max | 1e+8 |
start | 0. |
nominal | 1000 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.MassFractionExtends from Real.
| Name | Value |
|---|---|
quantity | "MassFraction" |
unit | "kg/kg" |
min | 0 |
max | 1 |
start | 0. |
nominal | 0.1 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.MoleFractionExtends from Real.
| Name | Value |
|---|---|
quantity | "MoleFraction" |
unit | "mol/mol" |
min | 0 |
max | 1 |
start | 0. |
nominal | 0.1 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.MolarMassExtends from Modelica.SIunits.MolarMass.
| Name | Value |
|---|---|
quantity | "MolarMass" |
unit | "kg/mol" |
min | 0.001 |
max | 0.25 |
start | 0. |
nominal | 0.032 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.MolarVolumeExtends from Modelica.SIunits.MolarVolume.
| Name | Value |
|---|---|
quantity | "MolarVolume" |
unit | "m3/mol" |
min | 1e-6 |
max | 1000000 |
start | 0. |
nominal | 1 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.IsentropicExponentExtends from Modelica.SIunits.RatioOfSpecificHeatCapacities.
| Name | Value |
|---|---|
quantity | "RatioOfSpecificHeatCapacities" |
unit | "1" |
min | 1 |
max | 500000 |
start | 1.2 |
nominal | 1.2 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.SpecificEnergyExtends from Modelica.SIunits.SpecificEnergy.
| Name | Value |
|---|---|
quantity | "SpecificEnergy" |
unit | "J/kg" |
min | -1e+8 |
max | 1e+8 |
start | 0. |
nominal | 1000000 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.SpecificInternalEnergyExtends from Modelica.Media.IdealGases.Common.MixtureGasNasa.SpecificEnergy (Type for specific energy with medium specific attributes).
| Name | Value |
|---|---|
quantity | "SpecificEnergy" |
unit | "J/kg" |
min | -1e+8 |
max | 1e+8 |
start | 0. |
nominal | 1000000 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.SpecificEnthalpyExtends from Modelica.SIunits.SpecificEnthalpy.
| Name | Value |
|---|---|
quantity | "SpecificEnergy" |
unit | "J/kg" |
min | -1e+10 |
max | 1e+10 |
start | if referenceChoice == ReferenceEnthalpy.ZeroAt0K then 300000 else if referenceChoice == ReferenceEnthalpy.UserDefined then h_offset else 0 |
nominal | 100000 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.SpecificEntropyExtends from Modelica.SIunits.SpecificEntropy.
| Name | Value |
|---|---|
quantity | "SpecificEntropy" |
unit | "J/(kg.K)" |
min | -1e+7 |
max | 1e+7 |
start | 0. |
nominal | 1000 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.SpecificHeatCapacityExtends from Modelica.SIunits.SpecificHeatCapacity.
| Name | Value |
|---|---|
quantity | "SpecificHeatCapacity" |
unit | "J/(kg.K)" |
min | 0 |
max | 1e+7 |
start | 1000 |
nominal | 1000 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.SurfaceTensionExtends from Modelica.SIunits.SurfaceTension.
| Name | Value |
|---|---|
quantity | "SurfaceTension" |
unit | "N/m" |
min | -Modelica.Constants.inf |
max | Modelica.Constants.inf |
start | 0. |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.TemperatureExtends from Modelica.SIunits.Temperature.
| Name | Value |
|---|---|
quantity | "ThermodynamicTemperature" |
unit | "K" |
displayUnit | "degC" |
min | 200 |
max | 6000 |
start | 500 |
nominal | 500 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.ThermalConductivityExtends from Modelica.SIunits.ThermalConductivity.
| Name | Value |
|---|---|
quantity | "ThermalConductivity" |
unit | "W/(m.K)" |
min | 0 |
max | 500 |
start | 1 |
nominal | 1 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.PrandtlNumberExtends from Modelica.SIunits.PrandtlNumber.
| Name | Value |
|---|---|
quantity | "PrandtlNumber" |
unit | "1" |
min | 0.001 |
max | 100000 |
start | 0. |
nominal | 1 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.VelocityOfSoundExtends from Modelica.SIunits.Velocity.
| Name | Value |
|---|---|
quantity | "Velocity" |
unit | "m/s" |
min | 0 |
max | 100000 |
start | 1000 |
nominal | 1000 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.ExtraPropertyExtends from Real.
| Name | Value |
|---|---|
min | 0 |
max | Modelica.Constants.inf |
start | 1 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.CumulativeExtraPropertyExtends from Real.
| Name | Value |
|---|---|
min | 0 |
max | Modelica.Constants.inf |
start | 1 |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.ExtraPropertyFlowRateExtends from Real.
| Name | Value |
|---|---|
unit | "kg/s" |
min | -Modelica.Constants.inf |
max | Modelica.Constants.inf |
start | 0. |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.IsobaricExpansionCoefficientExtends from Real.
| Name | Value |
|---|---|
unit | "1/K" |
min | 0 |
max | 1e+8 |
start | 0. |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.DipoleMomentExtends from Real.
| Name | Value |
|---|---|
quantity | "ElectricDipoleMoment" |
unit | "debye" |
min | 0 |
max | 2 |
start | 0. |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.DerDensityByPressureExtends from Modelica.SIunits.DerDensityByPressure.
| Name | Value |
|---|---|
unit | "s2/m2" |
min | -Modelica.Constants.inf |
max | Modelica.Constants.inf |
start | 0. |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.DerDensityByEnthalpyExtends from Modelica.SIunits.DerDensityByEnthalpy.
| Name | Value |
|---|---|
unit | "kg.s2/m5" |
min | -Modelica.Constants.inf |
max | Modelica.Constants.inf |
start | 0. |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.DerEnthalpyByPressureExtends from Modelica.SIunits.DerEnthalpyByPressure.
| Name | Value |
|---|---|
unit | "J.m.s2/kg2" |
min | -Modelica.Constants.inf |
max | Modelica.Constants.inf |
start | 0. |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.DerDensityByTemperatureExtends from Modelica.SIunits.DerDensityByTemperature.
| Name | Value |
|---|---|
unit | "kg/(m3.K)" |
min | -Modelica.Constants.inf |
max | Modelica.Constants.inf |
start | 0. |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.DerTemperatureByPressureExtends from Real.
| Name | Value |
|---|---|
unit | "K/Pa" |
min | -Modelica.Constants.inf |
max | Modelica.Constants.inf |
start | 0. |
Record Modelica.Media.IdealGases.Common.MixtureGasNasa.SaturationProperties
This icon is indicates a record.
Extends from Modelica.Icons.Record (Icon for records).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | psat | Saturation pressure |
Temperature | Tsat | Saturation temperature |
Record Modelica.Media.IdealGases.Common.MixtureGasNasa.FluidLimits
The minimum pressure mostly applies to the liquid state only. The minimum density is also arbitrary, but is reasonable for technical applications to limit iterations in non-linear systems. The limits in enthalpy and entropy are used as safeguards in inverse iterations.
Extends from Modelica.Icons.Record (Icon for records).
| Type | Name | Description |
|---|---|---|
Temperature | TMIN | Minimum temperature |
Temperature | TMAX | Maximum temperature |
Density | DMIN | Minimum density |
Density | DMAX | Maximum density |
AbsolutePressure | PMIN | Minimum pressure |
AbsolutePressure | PMAX | Maximum pressure |
SpecificEnthalpy | HMIN | Minimum enthalpy |
SpecificEnthalpy | HMAX | Maximum enthalpy |
SpecificEntropy | SMIN | Minimum entropy |
SpecificEntropy | SMAX | Maximum entropy |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.FixedPhaseExtends from Integer.
| Name | Value |
|---|---|
min | 0 |
max | 2 |
start | 0 |
Record Modelica.Media.IdealGases.Common.MixtureGasNasa.FluidConstants
This icon is indicates a record.
Extends from Modelica.Media.Interfaces.Types.IdealGas.FluidConstants (Extended fluid constants).
| Type | Name | Description |
|---|---|---|
String | iupacName | Complete IUPAC name (or common name, if non-existent) |
String | casRegistryNumber | Chemical abstracts sequencing number (if it exists) |
String | chemicalFormula | Chemical formula, (brutto, nomenclature according to Hill |
String | structureFormula | Chemical structure formula |
MolarMass | molarMass | Molar mass |
Temperature | criticalTemperature | Critical temperature |
AbsolutePressure | criticalPressure | Critical pressure |
MolarVolume | criticalMolarVolume | Critical molar Volume |
Real | acentricFactor | Pitzer acentric factor |
Temperature | meltingPoint | Melting point at 101325 Pa |
Temperature | normalBoilingPoint | Normal boiling point (at 101325 Pa) |
DipoleMoment | dipoleMoment | Dipole moment of molecule in Debye (1 debye = 3.33564e10-30 C.m) |
Boolean | hasIdealGasHeatCapacity | True if ideal gas heat capacity is available |
Boolean | hasCriticalData | True if critical data are known |
Boolean | hasDipoleMoment | True if a dipole moment known |
Boolean | hasFundamentalEquation | True if a fundamental equation |
Boolean | hasLiquidHeatCapacity | True if liquid heat capacity is available |
Boolean | hasSolidHeatCapacity | True if solid heat capacity is available |
Boolean | hasAccurateViscosityData | True if accurate data for a viscosity function is available |
Boolean | hasAccurateConductivityData | True if accurate data for thermal conductivity is available |
Boolean | hasVapourPressureCurve | True if vapour pressure data, e.g., Antoine coefficients are known |
Boolean | hasAcentricFactor | True if Pitzer acentric factor is known |
SpecificEnthalpy | HCRIT0 | Critical specific enthalpy of the fundamental equation |
SpecificEntropy | SCRIT0 | Critical specific entropy of the fundamental equation |
SpecificEnthalpy | deltah | Difference between specific enthalpy model (h_m) and f.eq. (h_f) (h_m - h_f) |
SpecificEntropy | deltas | Difference between specific enthalpy model (s_m) and f.eq. (s_f) (s_m - s_f) |
Record Modelica.Media.IdealGases.Common.MixtureGasNasa.ThermodynamicState
This icon is indicates a record.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.ThermodynamicState (Thermodynamic state variables).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Absolute pressure of medium |
Temperature | T | Temperature of medium |
MassFraction | X[nX] | Mass fractions (= (component mass)/total mass m_i/m) |
Model Modelica.Media.IdealGases.Common.MixtureGasNasa.BaseProperties
Model BaseProperties is a model within package PartialMedium and contains the declarations of the minimum number of variables that every medium model is supposed to support. A specific medium inherits from model BaseProperties and provides the equations for the basic properties.
The BaseProperties model contains the following 7+nXi variables (nXi is the number of independent mass fractions defined in package PartialMedium):
| Variable | Unit | Description |
| T | K | temperature |
| p | Pa | absolute pressure |
| d | kg/m3 | density |
| h | J/kg | specific enthalpy |
| u | J/kg | specific internal energy |
| Xi[nXi] | kg/kg | independent mass fractions m_i/m |
| R | J/kg.K | gas constant |
| M | kg/mol | molar mass |
In order to implement an actual medium model, one can extend from this base model and add 5 equations that provide relations among these variables. Equations will also have to be added in order to set all the variables within the ThermodynamicState record state.
If standardOrderComponents=true, the full composition vector X[nX] is determined by the equations contained in this base class, depending on the independent mass fraction vector Xi[nXi].
Additional 2 + nXi equations will have to be provided when using the BaseProperties model, in order to fully specify the thermodynamic conditions. The input connector qualifier applied to p, h, and nXi indirectly declares the number of missing equations, permitting advanced equation balance checking by Modelica tools. Please note that this doesn't mean that the additional equations should be connection equations, nor that exactly those variables should be supplied, in order to complete the model. For further information, see the Modelica.Media User's guide, and Section 4.7 (Balanced Models) of the Modelica 3.0 specification.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.BaseProperties (Base properties (p, d, T, h, u, R, MM and, if applicable, X and Xi) of a medium).
| Type | Name | Default | Description |
|---|---|---|---|
Boolean | preferredMediumStates | false | = true if StateSelect.prefer shall be used for the independent property variables of the medium |
final Boolean | standardOrderComponents | true | If true, and reducedX = true, the last element of X will be computed from the other ones |
| Type | Name | Description |
|---|---|---|
input InputAbsolutePressure | p | Absolute pressure of medium |
input InputMassFraction | Xi[nXi] | Structurally independent mass fractions |
input InputSpecificEnthalpy | h | Specific enthalpy of medium |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.setState_pTX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
Temperature | T | Temperature |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.setState_phX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
SpecificEnthalpy | h | Specific enthalpy |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.setState_psX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
SpecificEntropy | s | Specific entropy |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.setState_dTX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
Density | d | Density |
Temperature | T | Temperature |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.setSmoothState
This function is used to approximate the equation
state = if x > 0 then state_a else state_b;
by a smooth characteristic, so that the expression is continuous and differentiable:
state := smooth(1, if x > x_small then state_a else
if x < -x_small then state_b else f(state_a, state_b));
This is performed by applying function Media.Common.smoothStep(..) on every element of the thermodynamic state record.
If mass fractions X[:] are approximated with this function then this can be performed for all nX mass fractions, instead of applying it for nX-1 mass fractions and computing the last one by the mass fraction constraint sum(X)=1. The reason is that the approximating function has the property that sum(state.X) = 1, provided sum(state_a.X) = sum(state_b.X) = 1. This can be shown by evaluating the approximating function in the abs(x) < x_small region (otherwise state.X is either state_a.X or state_b.X):
X[1] = smoothStep(x, X_a[1] , X_b[1] , x_small);
X[2] = smoothStep(x, X_a[2] , X_b[2] , x_small);
...
X[nX] = smoothStep(x, X_a[nX], X_b[nX], x_small);
or
X[1] = c*(X_a[1] - X_b[1]) + (X_a[1] + X_b[1])/2
X[2] = c*(X_a[2] - X_b[2]) + (X_a[2] + X_b[2])/2;
...
X[nX] = c*(X_a[nX] - X_b[nX]) + (X_a[nX] + X_b[nX])/2;
c = (x/x_small)*((x/x_small)^2 - 3)/4
Summing all mass fractions together results in
sum(X) = c*(sum(X_a) - sum(X_b)) + (sum(X_a) + sum(X_b))/2
= c*(1 - 1) + (1 + 1)/2
= 1
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.setSmoothState (Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b).
| Type | Name | Description |
|---|---|---|
Real | x | m_flow or dp |
ThermodynamicState | state_a | Thermodynamic state if x > 0 |
ThermodynamicState | state_b | Thermodynamic state if x < 0 |
Real | x_small | Smooth transition in the region -x_small < x < x_small |
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Smooth thermodynamic state for all x (continuous and differentiable) |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.dynamicViscosity
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.dynamicViscosity (Return dynamic viscosity).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
DynamicViscosity | eta | Dynamic viscosity |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.thermalConductivity
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.thermalConductivity (Return thermal conductivity).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Integer | method | Method to compute single component thermal conductivity |
| Type | Name | Description |
|---|---|---|
ThermalConductivity | lambda | Thermal conductivity |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.prandtlNumber
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
PrandtlNumber | Pr | Prandtl number |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.pressure
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.pressure (Return pressure).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.temperature
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.temperature (Return temperature).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
Temperature | T | Temperature |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.density
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.density (Return density).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
Density | d | Density |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.specificEnthalpy
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.specificEnthalpy (Return specific enthalpy) and Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
SpecificEnthalpy | h | Specific enthalpy |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.specificInternalEnergy
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.specificInternalEnergy (Return specific internal energy) and Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
SpecificEnergy | u | Specific internal energy |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.specificEntropy
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.specificEntropy (Return specific entropy).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
SpecificEntropy | s | Specific entropy |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.specificGibbsEnergy
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.specificGibbsEnergy (Return specific Gibbs energy) and Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
SpecificEnergy | g | Specific Gibbs energy |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.specificHelmholtzEnergy
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.specificHelmholtzEnergy (Return specific Helmholtz energy) and Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
SpecificEnergy | f | Specific Helmholtz energy |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.specificHeatCapacityCp
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.specificHeatCapacityCp (Return specific heat capacity at constant pressure).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
SpecificHeatCapacity | cp | Specific heat capacity at constant pressure |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.heatCapacity_cp
This icon indicates Modelica functions.
Extends from Modelica.Media.IdealGases.Common.MixtureGasNasa.specificHeatCapacityCp (Return specific heat capacity at constant pressure).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
SpecificHeatCapacity | cp | Specific heat capacity at constant pressure |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.specificHeatCapacityCv
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.specificHeatCapacityCv (Return specific heat capacity at constant volume).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
SpecificHeatCapacity | cv | Specific heat capacity at constant volume |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.heatCapacity_cv
This icon indicates Modelica functions.
Extends from Modelica.Media.IdealGases.Common.MixtureGasNasa.specificHeatCapacityCv (Return specific heat capacity at constant volume from temperature and gas data).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
SpecificHeatCapacity | cv | Specific heat capacity at constant volume |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.isentropicExponent
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.isentropicExponent (Return isentropic exponent).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
IsentropicExponent | gamma | Isentropic exponent |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.isentropicEnthalpy
This function computes an isentropic state transformation:
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.isentropicEnthalpy (Return isentropic enthalpy).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p_downstream | Downstream pressure |
ThermodynamicState | refState | Reference state for entropy |
Boolean | exact | Flag whether exact or approximate version should be used |
| Type | Name | Description |
|---|---|---|
SpecificEnthalpy | h_is | Isentropic enthalpy |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.velocityOfSound
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.velocityOfSound (Return velocity of sound) and Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
VelocityOfSound | a | Velocity of sound |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.isobaricExpansionCoefficient
beta is defined as 1/v * der(v,T), with v = 1/d, at constant pressure p.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.isobaricExpansionCoefficient (Return overall the isobaric expansion coefficient beta).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
IsobaricExpansionCoefficient | beta | Isobaric expansion coefficient |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.beta
beta is defined as 1/v * der(v,T), with v = 1/d, at constant pressure p.
Extends from Modelica.Media.IdealGases.Common.MixtureGasNasa.isobaricExpansionCoefficient (Return isobaric expansion coefficient beta).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
IsobaricExpansionCoefficient | beta | Isobaric expansion coefficient |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.isothermalCompressibility
kappa is defined as - 1/v * der(v,p), with v = 1/d at constant temperature T.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.isothermalCompressibility (Return overall the isothermal compressibility factor).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
IsothermalCompressibility | kappa | Isothermal compressibility |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.kappa
kappa is defined as - 1/v * der(v,p), with v = 1/d at constant temperature T.
Extends from Modelica.Media.IdealGases.Common.MixtureGasNasa.isothermalCompressibility (Return isothermal compressibility factor).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
IsothermalCompressibility | kappa | Isothermal compressibility |
Partial Function Modelica.Media.IdealGases.Common.MixtureGasNasa.density_derp_h
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
DerDensityByPressure | ddph | Density derivative w.r.t. pressure |
Partial Function Modelica.Media.IdealGases.Common.MixtureGasNasa.density_derh_p
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
DerDensityByEnthalpy | ddhp | Density derivative w.r.t. specific enthalpy |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.density_derp_T
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.density_derp_T (Return density derivative w.r.t. pressure at const temperature).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
DerDensityByPressure | ddpT | Density derivative w.r.t. pressure |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.density_derT_p
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.density_derT_p (Return density derivative w.r.t. temperature at constant pressure).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
DerDensityByTemperature | ddTp | Density derivative w.r.t. temperature |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.density_derX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
Density | dddX[nX] | Derivative of density w.r.t. mass fraction |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.molarMass
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.molarMass (Return the molar mass of the medium).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
| Type | Name | Description |
|---|---|---|
MolarMass | MM | Mixture molar mass |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.specificEnthalpy_pTX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
Temperature | T | Temperature |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
SpecificEnthalpy | h | Specific enthalpy |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.specificEntropy_pTX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
Temperature | T | Temperature |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
SpecificEntropy | s | Specific entropy |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.density_pTX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
Temperature | T | Temperature |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
Density | d | Density |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.temperature_phX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
SpecificEnthalpy | h | Specific enthalpy |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
Temperature | T | Temperature |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.density_phX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
SpecificEnthalpy | h | Specific enthalpy |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
Density | d | Density |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.temperature_psX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
SpecificEntropy | s | Specific entropy |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
Temperature | T | Temperature |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.density_psX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
SpecificEntropy | s | Specific entropy |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
Density | d | Density |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.specificEnthalpy_psX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
SpecificEntropy | s | Specific entropy |
MassFraction | X[:] | Mass fractions |
| Type | Name | Description |
|---|---|---|
SpecificEnthalpy | h | Specific enthalpy |
Type Modelica.Media.IdealGases.Common.MixtureGasNasa.MassFlowRateExtends from Modelica.SIunits.MassFlowRate.
| Name | Value |
|---|---|
quantity | "MassFlowRate." + mediumName |
unit | "kg/s" |
min | -100000 |
max | 100000 |
start | 0. |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.gasConstant
This icon indicates Modelica functions.
Extends from Modelica.Media.Interfaces.PartialMixtureMedium.gasConstant (Return the gas constant of the mixture (also for liquids)).
| Type | Name | Description |
|---|---|---|
ThermodynamicState | state | Thermodynamic state |
| Type | Name | Description |
|---|---|---|
SpecificHeatCapacity | R | Mixture gas constant |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.moleToMassFractions
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
MoleFraction | moleFractions[:] | Mole fractions of mixture |
MolarMass | MMX[:] | Molar masses of components |
| Type | Name | Description |
|---|---|---|
MassFraction | X[size(moleFractions, 1)] | Mass fractions of gas mixture |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.massToMoleFractions
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
MassFraction | X[:] | Mass fractions of mixture |
MolarMass | MMX[:] | Molar masses of components |
| Type | Name | Description |
|---|---|---|
MoleFraction | moleFractions[size(X, 1)] | Mole fractions of gas mixture |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.h_TX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
Temperature | T | Temperature |
MassFraction | X[nX] | Independent Mass fractions of gas mixture |
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 |
| Type | Name | Description |
|---|---|---|
SpecificEnthalpy | h | Specific enthalpy at temperature T |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.h_TX_der
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
Temperature | T | Temperature |
MassFraction | X[nX] | Independent Mass fractions of gas mixture |
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 |
Real | dX[nX] | Independent mass fraction derivative |
| Type | Name | Description |
|---|---|---|
Real | h_der | Specific enthalpy at temperature T |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.MixEntropy
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
MoleFraction | x[:] | Mole fraction of mixture |
| Type | Name | Description |
|---|---|---|
Real | smix | Mixing entropy contribution, divided by gas constant |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.s_TX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
Temperature | T | Temperature |
MassFraction | X[nX] | Mass fraction |
| Type | Name | Description |
|---|---|---|
SpecificEntropy | s | Specific entropy |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.isentropicEnthalpyApproximation
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p2 | Downstream pressure |
ThermodynamicState | state | Thermodynamic state at upstream location |
| Type | Name | Description |
|---|---|---|
SpecificEnthalpy | h_is | Isentropic enthalpy |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.gasMixtureViscosity
Simplification of the kinetic theory (Chapman and Enskog theory)
approach neglecting the second-order effects.
This equation has been extensively tested (Amdur and Mason, 1958;
Bromley and Wilke, 1951; Cheung, 1958; Dahler, 1959; Gandhi and Saxena,
1964; Ranz and Brodowsky, 1962; Saxena and Gambhir, 1963a; Strunk, et
al., 1964; Vanderslice, et al. 1962; Wright and Gray, 1962). In most
cases, only nonpolar mixtures were compared, and very good results
obtained. For some systems containing hydrogen as one component, less
satisfactory agreement was noted. Wilke's method predicted mixture
viscosities that were larger than experimental for the H2-N2 system,
but for H2-NH3, it underestimated the viscosities.
Gururaja, et al. (1967) found that this method also overpredicted in
the H2-O2 case but was quite accurate for the H2-CO2 system.
Wilke's approximation has proved reliable even for polar-polar gas
mixtures of aliphatic alcohols (Reid and Belenyessy, 1960). The
principal reservation appears to lie in those cases where Mi>>Mj
and etai>>etaj.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
MoleFraction | yi[:] | Mole fractions |
MolarMass | M[size(yi, 1)] | Mole masses |
DynamicViscosity | eta[size(yi, 1)] | Pure component viscosities |
| Type | Name | Description |
|---|---|---|
DynamicViscosity | etam | Viscosity of the mixture |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.mixtureViscosityChung
Equation to estimate the viscosity of gas mixtures at low pressures.
It is a simplification of an extension of the rigorous kinetic theory
of Chapman and Enskog to determine the viscosity of multicomponent
mixtures, at low pressures and with a factor to correct for molecule
shape and polarity.
The input argument Kappa is a special correction for highly polar substances such as
alcohols and acids.
Values of kappa for a few such materials:
| Compound |
Kappa |
Compound |
Kappa |
| Methanol |
0.215 |
n-Pentanol |
0.122 |
| Ethanol |
0.175 |
n-Hexanol |
0.114 |
| n-Propanol |
0.143 |
n-Heptanol |
0.109 |
| i-Propanol |
0.143 |
Acetic Acid |
0.0916 |
| n-Butanol |
0.132 |
Water |
0.076 |
| i-Butanol |
0.132 |
Chung, et al. (1984) suggest that for other alcohols not shown in the
table:
kappa = 0.0682 + 4.704*[(number of -OH
groups)]/[molecular weight]
S.I. units relation for the
debyes:
1 debye = 3.162e-25 (J.m^3)^(1/2)
[1] THE PROPERTIES OF GASES AND LIQUIDS, Fifth Edition,
Bruce E. Poling, John M.
Prausnitz, John P. O'Connell.
[2] Chung, T.-H., M. Ajlan, L. L. Lee, and K. E. Starling: Ind. Eng.
Chem. Res., 27: 671 (1988).
[3] Chung, T.-H., L. L. Lee, and K. E. Starling; Ing. Eng. Chem.
Fundam., 23: 3 ()1984).
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
Temperature | T | Temperature |
Temperature | Tc[nX] | Critical temperatures |
MolarVolume | Vcrit[nX] | Critical volumes (m3/mol) |
Real | w[nX] | Acentric factors |
Real | mu[nX] | Dipole moments (debyes) |
MolarMass | MolecularWeights[nX] | Molecular weights (kg/mol) |
MoleFraction | y[nX] | Molar Fractions |
Real | kappa[nX] | Association Factors |
| Type | Name | Description |
|---|---|---|
DynamicViscosity | etaMixture | Mixture viscosity (Pa.s) |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.lowPressureThermalConductivity
This function applies the Masson and Saxena modification of the Wassiljewa Equation for the thermal conductivity for gas mixtures of n elements at low pressure.
For nonpolar gas mixtures errors will generally be less than 3 to 4%. For mixtures of nonpolar-polar and polar-polar gases, errors greater than 5 to 8% may be expected. For mixtures in which the sizes and polarities of the constituent molecules are not greatly different, the thermal conductivity can be estimated satisfactorily by a mole fraction average of the pure component conductivities.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
MoleFraction | y[:] | Mole fraction of the components in the gas mixture |
Temperature | T | Temperature |
Temperature | Tc[size(y, 1)] | Critical temperatures |
AbsolutePressure | Pc[size(y, 1)] | Critical pressures |
MolarMass | M[size(y, 1)] | Molecular weights |
ThermalConductivity | lambda[size(y, 1)] | Thermal conductivities of the pure gases |
| Type | Name | Description |
|---|---|---|
ThermalConductivity | lambdam | Thermal conductivity of the gas mixture |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.T_hX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
SpecificEnthalpy | h | Specific enthalpy |
MassFraction | X[nX] | Mass fractions of composition |
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 |
| Type | Name | Description |
|---|---|---|
Temperature | T | Temperature |
Function Modelica.Media.IdealGases.Common.MixtureGasNasa.T_psX
This icon indicates Modelica functions.
Extends from Modelica.Icons.Function (Icon for functions).
| Type | Name | Description |
|---|---|---|
AbsolutePressure | p | Pressure |
SpecificEntropy | s | Specific entropy |
MassFraction | X[nX] | Mass fractions of composition |
| Type | Name | Description |
|---|---|---|
Temperature | T | Temperature |