Modelica.Media.IdealGases.Common.SingleGasNasa

Medium model of an ideal gas based on NASA source

Information


This model calculates medium properties for an ideal gas of a single substance, or for an ideal gas consisting of several substances where the mass fractions are fixed. Independent variables are temperature T and pressure p. Only density is a function of T and p. All other quantities are solely a function of T. The properties are valid in the range:

   200 K ≤ T ≤ 6000 K

The following quantities are always computed:

Variable Unit Description
h J/kg specific enthalpy h = h(T)
u J/kg specific internal energy u = u(T)
d kg/m^3 density d = d(p,T)

For the other variables, see the functions in Modelica.Media.IdealGases.Common.SingleGasNasa. Note, dynamic viscosity and thermal conductivity are only provided for gases that use a data record from Modelica.Media.IdealGases.FluidData. Currently these are the following gases:

  Ar
  C2H2_vinylidene
  C2H4
  C2H5OH
  C2H6
  C3H6_propylene
  C3H7OH
  C3H8
  C4H8_1_butene
  C4H9OH
  C4H10_n_butane
  C5H10_1_pentene
  C5H12_n_pentane
  C6H6
  C6H12_1_hexene
  C6H14_n_heptane
  C7H14_1_heptene
  C8H10_ethylbenz
  CH3OH
  CH4
  CL2
  CO
  CO2
  F2
  H2
  H2O
  He
  N2
  N2O
  NH3
  NO
  O2
  SO2
  SO3

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 200K and 6000K. A few of the data sets for monatomic gases have a discontinuous 1st derivative at 1000K, but this never caused problems so far.

This model has been copied from the ThermoFluid library and adapted to the Modelica.Media package.

Extends from Interfaces.PartialPureSubstance (Base class for pure substances of one chemical substance).

Package Content

NameDescription
Modelica.Media.IdealGases.Common.SingleGasNasa.ThermodynamicState ThermodynamicState Thermodynamic state variables for ideal gases
dataData record of ideal gas substance
fluidConstantsConstant data for the fluid
Modelica.Media.IdealGases.Common.SingleGasNasa.BaseProperties BaseProperties Base properties of ideal gas medium
Modelica.Media.IdealGases.Common.SingleGasNasa.setState_pTX setState_pTX Return thermodynamic state as function of p, T and composition X
Modelica.Media.IdealGases.Common.SingleGasNasa.setState_phX setState_phX Return thermodynamic state as function of p, h and composition X
Modelica.Media.IdealGases.Common.SingleGasNasa.setState_psX setState_psX Return thermodynamic state as function of p, s and composition X
Modelica.Media.IdealGases.Common.SingleGasNasa.setState_dTX setState_dTX Return thermodynamic state as function of d, T and composition X
Modelica.Media.IdealGases.Common.SingleGasNasa.setSmoothState setSmoothState Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b
Modelica.Media.IdealGases.Common.SingleGasNasa.pressure pressure Return pressure of ideal gas
Modelica.Media.IdealGases.Common.SingleGasNasa.temperature temperature Return temperature of ideal gas
Modelica.Media.IdealGases.Common.SingleGasNasa.density density Return density of ideal gas
Modelica.Media.IdealGases.Common.SingleGasNasa.specificEnthalpy specificEnthalpy Return specific enthalpy
Modelica.Media.IdealGases.Common.SingleGasNasa.specificInternalEnergy specificInternalEnergy Return specific internal energy
Modelica.Media.IdealGases.Common.SingleGasNasa.specificEntropy specificEntropy Return specific entropy
Modelica.Media.IdealGases.Common.SingleGasNasa.specificGibbsEnergy specificGibbsEnergy Return specific Gibbs energy
Modelica.Media.IdealGases.Common.SingleGasNasa.specificHelmholtzEnergy specificHelmholtzEnergy Return specific Helmholtz energy
Modelica.Media.IdealGases.Common.SingleGasNasa.specificHeatCapacityCp specificHeatCapacityCp Return specific heat capacity at constant pressure
Modelica.Media.IdealGases.Common.SingleGasNasa.specificHeatCapacityCv specificHeatCapacityCv Compute specific heat capacity at constant volume from temperature and gas data
Modelica.Media.IdealGases.Common.SingleGasNasa.isentropicExponent isentropicExponent Return isentropic exponent
Modelica.Media.IdealGases.Common.SingleGasNasa.velocityOfSound velocityOfSound Return velocity of sound
Modelica.Media.IdealGases.Common.SingleGasNasa.isentropicEnthalpyApproximation isentropicEnthalpyApproximation Approximate method of calculating h_is from upstream properties and downstream pressure
Modelica.Media.IdealGases.Common.SingleGasNasa.isentropicEnthalpy isentropicEnthalpy Return isentropic enthalpy
Modelica.Media.IdealGases.Common.SingleGasNasa.isobaricExpansionCoefficient isobaricExpansionCoefficient Returns overall the isobaric expansion coefficient beta
Modelica.Media.IdealGases.Common.SingleGasNasa.isothermalCompressibility isothermalCompressibility Returns overall the isothermal compressibility factor
Modelica.Media.IdealGases.Common.SingleGasNasa.density_derp_T density_derp_T Returns the partial derivative of density with respect to pressure at constant temperature
Modelica.Media.IdealGases.Common.SingleGasNasa.density_derT_p density_derT_p Returns the partial derivative of density with respect to temperature at constant pressure
Modelica.Media.IdealGases.Common.SingleGasNasa.density_derX density_derX Returns the partial derivative of density with respect to mass fractions at constant pressure and temperature
Modelica.Media.IdealGases.Common.SingleGasNasa.dynamicViscosity dynamicViscosity Dynamic viscosity
Modelica.Media.IdealGases.Common.SingleGasNasa.thermalConductivity thermalConductivity Thermal conductivity of gas
Modelica.Media.IdealGases.Common.SingleGasNasa.molarMass molarMass Return the molar mass of the medium
Modelica.Media.IdealGases.Common.SingleGasNasa.T_h T_h Compute temperature from specific enthalpy
Modelica.Media.IdealGases.Common.SingleGasNasa.T_ps T_ps Compute temperature from pressure and specific entropy
Modelica.Media.IdealGases.Common.SingleGasNasa.dynamicViscosityLowPressure dynamicViscosityLowPressure Dynamic viscosity of low pressure gases
Modelica.Media.IdealGases.Common.SingleGasNasa.thermalConductivityEstimate thermalConductivityEstimate Thermal conductivity of polyatomic gases(Eucken and Modified Eucken correlation)
Inherited
Modelica.Media.Interfaces.PartialPureSubstance.setState_pT setState_pT Return thermodynamic state from p and T
Modelica.Media.Interfaces.PartialPureSubstance.setState_ph setState_ph Return thermodynamic state from p and h
Modelica.Media.Interfaces.PartialPureSubstance.setState_ps setState_ps Return thermodynamic state from p and s
Modelica.Media.Interfaces.PartialPureSubstance.setState_dT setState_dT Return thermodynamic state from d and T
Modelica.Media.Interfaces.PartialPureSubstance.density_ph density_ph Return density from p and h
Modelica.Media.Interfaces.PartialPureSubstance.temperature_ph temperature_ph Return temperature from p and h
Modelica.Media.Interfaces.PartialPureSubstance.pressure_dT pressure_dT Return pressure from d and T
Modelica.Media.Interfaces.PartialPureSubstance.specificEnthalpy_dT specificEnthalpy_dT Return specific enthalpy from d and T
Modelica.Media.Interfaces.PartialPureSubstance.specificEnthalpy_ps specificEnthalpy_ps Return specific enthalpy from p and s
Modelica.Media.Interfaces.PartialPureSubstance.temperature_ps temperature_ps Return temperature from p and s
Modelica.Media.Interfaces.PartialPureSubstance.density_ps density_ps Return density from p and s
Modelica.Media.Interfaces.PartialPureSubstance.specificEnthalpy_pT specificEnthalpy_pT Return specific enthalpy from p and T
Modelica.Media.Interfaces.PartialPureSubstance.density_pT density_pT Return density from p and T
ThermoStatesEnumeration type for independent variables
mediumName="unusablePartialMedium"Name of the medium
substanceNames={mediumName}Names of the mixture substances. Set substanceNames={mediumName} if only one substance.
extraPropertiesNames=fill("", 0)Names of the additional (extra) transported properties. Set extraPropertiesNames=fill("",0) if unused
singleState= true, if u and d are not a function of pressure
reducedX=true= true if medium contains the equation sum(X) = 1.0; set reducedX=true if only one substance (see docu for details)
fixedX=false= true if medium contains the equation X = reference_X
reference_p=101325Reference pressure of Medium: default 1 atmosphere
reference_T=298.15Reference temperature of Medium: default 25 deg Celsius
reference_X=fill(1/nX, nX)Default mass fractions of medium
p_default=101325Default value for pressure of medium (for initialization)
T_default=Modelica.SIunits.Conversions.from_degC(20)Default value for temperature of medium (for initialization)
h_default=specificEnthalpy_pTX(p_default, T_default, X_default)Default value for specific enthalpy of medium (for initialization)
X_default=reference_XDefault value for mass fractions of medium (for initialization)
nS=size(substanceNames, 1)Number of substances
nX=nSNumber of mass fractions
nXi=if fixedX then 0 else if reducedX then nS - 1 else nSNumber of structurally independent mass fractions (see docu for details)
nC=size(extraPropertiesNames, 1)Number of extra (outside of standard mass-balance) transported properties
C_nominal=1.0e-6*ones(nC)Default for the nominal values for the extra properties
Modelica.Media.Interfaces.PartialMedium.FluidConstants FluidConstants Critical, triple, molecular and other standard data of fluid
Modelica.Media.Interfaces.PartialMedium.prandtlNumber prandtlNumber Return the Prandtl number
Modelica.Media.Interfaces.PartialMedium.heatCapacity_cp heatCapacity_cp Alias for deprecated name
Modelica.Media.Interfaces.PartialMedium.heatCapacity_cv heatCapacity_cv Alias for deprecated name
Modelica.Media.Interfaces.PartialMedium.beta beta Alias for isobaricExpansionCoefficient for user convenience
Modelica.Media.Interfaces.PartialMedium.kappa kappa Alias of isothermalCompressibility for user convenience
Modelica.Media.Interfaces.PartialMedium.density_derp_h density_derp_h Return density derivative w.r.t. pressure at const specific enthalpy
Modelica.Media.Interfaces.PartialMedium.density_derh_p density_derh_p Return density derivative w.r.t. specific enthalpy at constant pressure
Modelica.Media.Interfaces.PartialMedium.specificEnthalpy_pTX specificEnthalpy_pTX Return specific enthalpy from p, T, and X or Xi
Modelica.Media.Interfaces.PartialMedium.specificEntropy_pTX specificEntropy_pTX Return specific enthalpy from p, T, and X or Xi
Modelica.Media.Interfaces.PartialMedium.density_pTX density_pTX Return density from p, T, and X or Xi
Modelica.Media.Interfaces.PartialMedium.temperature_phX temperature_phX Return temperature from p, h, and X or Xi
Modelica.Media.Interfaces.PartialMedium.density_phX density_phX Return density from p, h, and X or Xi
Modelica.Media.Interfaces.PartialMedium.temperature_psX temperature_psX Return temperature from p,s, and X or Xi
Modelica.Media.Interfaces.PartialMedium.density_psX density_psX Return density from p, s, and X or Xi
Modelica.Media.Interfaces.PartialMedium.specificEnthalpy_psX specificEnthalpy_psX Return specific enthalpy from p, s, and X or Xi
MassFlowRate Type for mass flow rate with medium specific attributes
AbsolutePressure Type for absolute pressure with medium specific attributes
Density Type for density with medium specific attributes
DynamicViscosity Type for dynamic viscosity with medium specific attributes
EnthalpyFlowRate Type for enthalpy flow rate with medium specific attributes
MassFraction Type for mass fraction with medium specific attributes
MoleFraction Type for mole fraction with medium specific attributes
MolarMass Type for molar mass with medium specific attributes
MolarVolume Type for molar volume with medium specific attributes
IsentropicExponent Type for isentropic exponent with medium specific attributes
SpecificEnergy Type for specific energy with medium specific attributes
SpecificInternalEnergy Type for specific internal energy with medium specific attributes
SpecificEnthalpy Type for specific enthalpy with medium specific attributes
SpecificEntropy Type for specific entropy with medium specific attributes
SpecificHeatCapacity Type for specific heat capacity with medium specific attributes
SurfaceTension Type for surface tension with medium specific attributes
Temperature Type for temperature with medium specific attributes
ThermalConductivity Type for thermal conductivity with medium specific attributes
PrandtlNumber Type for Prandtl number with medium specific attributes
VelocityOfSound Type for velocity of sound with medium specific attributes
ExtraProperty Type for unspecified, mass-specific property transported by flow
CumulativeExtraProperty Type for conserved integral of unspecified, mass specific property
ExtraPropertyFlowRate Type for flow rate of unspecified, mass-specific property
IsobaricExpansionCoefficient Type for isobaric expansion coefficient with medium specific attributes
DipoleMoment Type for dipole moment with medium specific attributes
DerDensityByPressure Type for partial derivative of density with respect to pressure with medium specific attributes
DerDensityByEnthalpy Type for partial derivative of density with respect to enthalpy with medium specific attributes
DerEnthalpyByPressure Type for partial derivative of enthalpy with respect to pressure with medium specific attributes
DerDensityByTemperature Type for partial derivative of density with respect to temperature with medium specific attributes
DerTemperatureByPressure Type for partial derivative of temperature with respect to pressure with medium specific attributes
Modelica.Media.Interfaces.Types.SaturationProperties SaturationProperties Saturation properties of two phase medium
Modelica.Media.Interfaces.Types.FluidLimits FluidLimits Validity limits for fluid model
FixedPhase Phase of the fluid: 1 for 1-phase, 2 for two-phase, 0 for not known, e.g., interactive use
Modelica.Media.Interfaces.Types.Basic Basic The most basic version of a record used in several degrees of detail
Modelica.Media.Interfaces.Types.IdealGas IdealGas The ideal gas version of a record used in several degrees of detail
Modelica.Media.Interfaces.Types.TwoPhase TwoPhase The two phase fluid version of a record used in several degrees of detail

Modelica.Media.IdealGases.Common.SingleGasNasa.ThermodynamicState Modelica.Media.IdealGases.Common.SingleGasNasa.ThermodynamicState

Thermodynamic state variables for ideal gases

Information

Extends from (Minimal variable set that is available as input argument to every medium function).

Modelica.Media.IdealGases.Common.SingleGasNasa.BaseProperties Modelica.Media.IdealGases.Common.SingleGasNasa.BaseProperties

Base properties of ideal gas medium

Information

Extends from .

Parameters

NameDescription
Advanced
preferredMediumStates= true if StateSelect.prefer shall be used for the independent property variables of the medium

Modelica.Media.IdealGases.Common.SingleGasNasa.setState_pTX Modelica.Media.IdealGases.Common.SingleGasNasa.setState_pTX

Return thermodynamic state as function of p, T and composition X

Information

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

Inputs

NameDescription
pPressure [Pa]
TTemperature [K]
X[:]Mass fractions [kg/kg]

Outputs

NameDescription
state 

Modelica.Media.IdealGases.Common.SingleGasNasa.setState_phX Modelica.Media.IdealGases.Common.SingleGasNasa.setState_phX

Return thermodynamic state as function of p, h and composition X

Information

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

Inputs

NameDescription
pPressure [Pa]
hSpecific enthalpy [J/kg]
X[:]Mass fractions [kg/kg]

Outputs

NameDescription
state 

Modelica.Media.IdealGases.Common.SingleGasNasa.setState_psX Modelica.Media.IdealGases.Common.SingleGasNasa.setState_psX

Return thermodynamic state as function of p, s and composition X

Information

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

Inputs

NameDescription
pPressure [Pa]
sSpecific entropy [J/(kg.K)]
X[:]Mass fractions [kg/kg]

Outputs

NameDescription
state 

Modelica.Media.IdealGases.Common.SingleGasNasa.setState_dTX Modelica.Media.IdealGases.Common.SingleGasNasa.setState_dTX

Return thermodynamic state as function of d, T and composition X

Information

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

Inputs

NameDescription
dDensity [kg/m3]
TTemperature [K]
X[:]Mass fractions [kg/kg]

Outputs

NameDescription
state 

Modelica.Media.IdealGases.Common.SingleGasNasa.setSmoothState Modelica.Media.IdealGases.Common.SingleGasNasa.setSmoothState

Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b

Information

Extends from (Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b).

Inputs

NameDescription
xm_flow or dp
state_aThermodynamic state if x > 0
state_bThermodynamic state if x < 0
x_smallSmooth transition in the region -x_small < x < x_small

Outputs

NameDescription
stateSmooth thermodynamic state for all x (continuous and differentiable)

Modelica.Media.IdealGases.Common.SingleGasNasa.pressure Modelica.Media.IdealGases.Common.SingleGasNasa.pressure

Return pressure of ideal gas

Information

Extends from (Return pressure).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
pPressure [Pa]

Modelica.Media.IdealGases.Common.SingleGasNasa.temperature Modelica.Media.IdealGases.Common.SingleGasNasa.temperature

Return temperature of ideal gas

Information

Extends from (Return temperature).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
TTemperature [K]

Modelica.Media.IdealGases.Common.SingleGasNasa.density Modelica.Media.IdealGases.Common.SingleGasNasa.density

Return density of ideal gas

Information

Extends from (Return density).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
dDensity [kg/m3]

Modelica.Media.IdealGases.Common.SingleGasNasa.specificEnthalpy Modelica.Media.IdealGases.Common.SingleGasNasa.specificEnthalpy

Return specific enthalpy

Information

Extends from Modelica.Icons.Function (Icon for functions), (Return specific enthalpy).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
hSpecific enthalpy [J/kg]

Modelica.Media.IdealGases.Common.SingleGasNasa.specificInternalEnergy Modelica.Media.IdealGases.Common.SingleGasNasa.specificInternalEnergy

Return specific internal energy

Information

Extends from Modelica.Icons.Function (Icon for functions), (Return specific internal energy).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
uSpecific internal energy [J/kg]

Modelica.Media.IdealGases.Common.SingleGasNasa.specificEntropy Modelica.Media.IdealGases.Common.SingleGasNasa.specificEntropy

Return specific entropy

Information

Extends from Modelica.Icons.Function (Icon for functions), (Return specific entropy).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
sSpecific entropy [J/(kg.K)]

Modelica.Media.IdealGases.Common.SingleGasNasa.specificGibbsEnergy Modelica.Media.IdealGases.Common.SingleGasNasa.specificGibbsEnergy

Return specific Gibbs energy

Information

Extends from Modelica.Icons.Function (Icon for functions), (Return specific Gibbs energy).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
gSpecific Gibbs energy [J/kg]

Modelica.Media.IdealGases.Common.SingleGasNasa.specificHelmholtzEnergy Modelica.Media.IdealGases.Common.SingleGasNasa.specificHelmholtzEnergy

Return specific Helmholtz energy

Information

Extends from Modelica.Icons.Function (Icon for functions), (Return specific Helmholtz energy).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
fSpecific Helmholtz energy [J/kg]

Modelica.Media.IdealGases.Common.SingleGasNasa.specificHeatCapacityCp Modelica.Media.IdealGases.Common.SingleGasNasa.specificHeatCapacityCp

Return specific heat capacity at constant pressure

Information

Extends from (Return specific heat capacity at constant pressure).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
cpSpecific heat capacity at constant pressure [J/(kg.K)]

Modelica.Media.IdealGases.Common.SingleGasNasa.specificHeatCapacityCv Modelica.Media.IdealGases.Common.SingleGasNasa.specificHeatCapacityCv

Compute specific heat capacity at constant volume from temperature and gas data

Information

Extends from (Return specific heat capacity at constant volume).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
cvSpecific heat capacity at constant volume [J/(kg.K)]

Modelica.Media.IdealGases.Common.SingleGasNasa.isentropicExponent Modelica.Media.IdealGases.Common.SingleGasNasa.isentropicExponent

Return isentropic exponent

Information

Extends from (Return isentropic exponent).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
gammaIsentropic exponent [1]

Modelica.Media.IdealGases.Common.SingleGasNasa.velocityOfSound Modelica.Media.IdealGases.Common.SingleGasNasa.velocityOfSound

Return velocity of sound

Information

Extends from Modelica.Icons.Function (Icon for functions), (Return velocity of sound).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
aVelocity of sound [m/s]

Modelica.Media.IdealGases.Common.SingleGasNasa.isentropicEnthalpyApproximation Modelica.Media.IdealGases.Common.SingleGasNasa.isentropicEnthalpyApproximation

Approximate method of calculating h_is from upstream properties and downstream pressure

Information

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

Inputs

NameDescription
p2Downstream pressure [Pa]
stateProperties at upstream location
exclEnthFormIf true, enthalpy of formation Hf is not included in specific enthalpy h
refChoiceChoice of reference enthalpy
h_offUser defined offset for reference enthalpy, if referenceChoice = UserDefined [J/kg]

Outputs

NameDescription
h_isIsentropic enthalpy [J/kg]

Modelica.Media.IdealGases.Common.SingleGasNasa.isentropicEnthalpy Modelica.Media.IdealGases.Common.SingleGasNasa.isentropicEnthalpy

Return isentropic enthalpy

Information

Extends from (Return isentropic enthalpy).

Inputs

NameDescription
exclEnthFormIf true, enthalpy of formation Hf is not included in specific enthalpy h
refChoiceChoice of reference enthalpy
h_offUser defined offset for reference enthalpy, if referenceChoice = UserDefined [J/kg]
p_downstreamDownstream pressure [Pa]
refStateReference state for entropy

Outputs

NameDescription
h_isIsentropic enthalpy [J/kg]

Modelica.Media.IdealGases.Common.SingleGasNasa.isobaricExpansionCoefficient Modelica.Media.IdealGases.Common.SingleGasNasa.isobaricExpansionCoefficient

Returns overall the isobaric expansion coefficient beta

Information

Extends from (Return overall the isobaric expansion coefficient beta).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
betaIsobaric expansion coefficient [1/K]

Modelica.Media.IdealGases.Common.SingleGasNasa.isothermalCompressibility Modelica.Media.IdealGases.Common.SingleGasNasa.isothermalCompressibility

Returns overall the isothermal compressibility factor

Information

Extends from (Return overall the isothermal compressibility factor).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
kappaIsothermal compressibility [1/Pa]

Modelica.Media.IdealGases.Common.SingleGasNasa.density_derp_T Modelica.Media.IdealGases.Common.SingleGasNasa.density_derp_T

Returns the partial derivative of density with respect to pressure at constant temperature

Information

Extends from (Return density derivative w.r.t. pressure at const temperature).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
ddpTDensity derivative w.r.t. pressure [s2/m2]

Modelica.Media.IdealGases.Common.SingleGasNasa.density_derT_p Modelica.Media.IdealGases.Common.SingleGasNasa.density_derT_p

Returns the partial derivative of density with respect to temperature at constant pressure

Information

Extends from (Return density derivative w.r.t. temperature at constant pressure).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
ddTpDensity derivative w.r.t. temperature [kg/(m3.K)]

Modelica.Media.IdealGases.Common.SingleGasNasa.density_derX Modelica.Media.IdealGases.Common.SingleGasNasa.density_derX

Returns the partial derivative of density with respect to mass fractions at constant pressure and temperature

Information

Extends from (Return density derivative w.r.t. mass fraction).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
dddX[nX]Derivative of density w.r.t. mass fraction [kg/m3]

Modelica.Media.IdealGases.Common.SingleGasNasa.dynamicViscosity Modelica.Media.IdealGases.Common.SingleGasNasa.dynamicViscosity

Dynamic viscosity

Information

Extends from (Return dynamic viscosity).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
etaDynamic viscosity [Pa.s]

Modelica.Media.IdealGases.Common.SingleGasNasa.thermalConductivity Modelica.Media.IdealGases.Common.SingleGasNasa.thermalConductivity

Thermal conductivity of gas

Information

Extends from (Return thermal conductivity).

Inputs

NameDescription
method1: Eucken Method, 2: Modified Eucken Method
stateThermodynamic state record

Outputs

NameDescription
lambdaThermal conductivity [W/(m.K)]

Modelica.Media.IdealGases.Common.SingleGasNasa.molarMass Modelica.Media.IdealGases.Common.SingleGasNasa.molarMass

Return the molar mass of the medium

Information

Extends from (Return the molar mass of the medium).

Inputs

NameDescription
stateThermodynamic state record

Outputs

NameDescription
MMMixture molar mass [kg/mol]

Modelica.Media.IdealGases.Common.SingleGasNasa.T_h Modelica.Media.IdealGases.Common.SingleGasNasa.T_h

Compute temperature from specific enthalpy

Information

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

Inputs

NameDescription
hSpecific enthalpy [J/kg]

Outputs

NameDescription
TTemperature [K]

Modelica.Media.IdealGases.Common.SingleGasNasa.T_ps Modelica.Media.IdealGases.Common.SingleGasNasa.T_ps

Compute temperature from pressure and specific entropy

Information

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

Inputs

NameDescription
pPressure [Pa]
sSpecific entropy [J/(kg.K)]

Outputs

NameDescription
TTemperature [K]

Modelica.Media.IdealGases.Common.SingleGasNasa.dynamicViscosityLowPressure Modelica.Media.IdealGases.Common.SingleGasNasa.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

NameDescription
TGas temperature [K]
TcCritical temperature of gas [K]
MMolar mass of gas [kg/mol]
VcCritical molar volume of gas [m3/mol]
wAcentric factor of gas
muDipole moment of gas molecule [debye]
kSpecial correction for highly polar substances

Outputs

NameDescription
etaDynamic viscosity of gas [Pa.s]

Modelica.Media.IdealGases.Common.SingleGasNasa.thermalConductivityEstimate Modelica.Media.IdealGases.Common.SingleGasNasa.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

NameDescription
CpConstant pressure heat capacity [J/(kg.K)]
etaDynamic viscosity [Pa.s]
method1: Eucken Method, 2: Modified Eucken Method
dataIdeal gas data

Outputs

NameDescription
lambdaThermal conductivity [W/(m.k)] [W/(m.K)]

Automatically generated Mon Sep 23 17:21:02 2013.