WOLFRAM SYSTEM MODELER

SingleGasNasa

Medium model of an ideal gas based on NASA source

Package Contents

	ThermodynamicState Thermodynamic state variables for ideal gases
	BaseProperties Base properties of ideal gas medium
	setState_pTX Return thermodynamic state as function of p, 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_dTX Return thermodynamic state as function of d, T and composition X
	setSmoothState Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b
	pressure Return pressure of ideal gas
	temperature Return temperature of ideal gas
	density Return density of ideal gas
	specificEnthalpy Return specific enthalpy
	specificInternalEnergy Return specific internal energy
	specificEntropy Return specific entropy
	specificGibbsEnergy Return specific Gibbs energy
	specificHelmholtzEnergy Return specific Helmholtz energy
	specificHeatCapacityCp Return specific heat capacity at constant pressure
	specificHeatCapacityCv Compute specific heat capacity at constant volume from temperature and gas data
	isentropicExponent Return isentropic exponent
	velocityOfSound Return velocity of sound
	isentropicEnthalpyApproximation Approximate method of calculating h_is from upstream properties and downstream pressure
	isentropicEnthalpy Return isentropic enthalpy
	isobaricExpansionCoefficient Returns overall the isobaric expansion coefficient beta
	isothermalCompressibility Returns overall the isothermal compressibility factor
	density_derp_T Returns the partial derivative of density with respect to pressure at constant temperature
	density_derT_p Returns the partial derivative of density with respect to temperature at constant pressure
	density_derX Returns the partial derivative of density with respect to mass fractions at constant pressure and temperature
	dynamicViscosity Dynamic viscosity
	thermalConductivity Thermal conductivity of gas
	molarMass Return the molar mass of the medium
	T_h Compute temperature from specific enthalpy
	T_ps Compute temperature from pressure and specific entropy
	dynamicViscosityLowPressure Dynamic viscosity of low pressure gases
	thermalConductivityEstimate Thermal conductivity of polyatomic gases(Eucken and Modified Eucken correlation)

Package Constants (22)

ThermoStates	Value: Modelica.Media.Interfaces.Choices.IndependentVariables.pT Type: IndependentVariables Description: Enumeration type for independent variables
mediumName	Value: data.name Type: String Description: Name of the medium
substanceNames	Value: {data.name} Type: String[:] Description: Names of the mixture substances. Set substanceNames={mediumName} if only one substance.
extraPropertiesNames	Value: fill("", 0) Type: String[:] Description: Names of the additional (extra) transported properties. Set extraPropertiesNames=fill("",0) if unused
singleState	Value: false Type: Boolean Description: = true, if u and d are not a function of pressure
reducedX	Value: true Type: Boolean Description: = true if medium contains the equation sum(X) = 1.0; set reducedX=true if only one substance (see docu for details)
fixedX	Value: true Type: Boolean Description: = true if medium contains the equation X = reference_X
reference_p	Value: 101325 Type: AbsolutePressure (Pa) Description: Reference pressure of Medium: default 1 atmosphere
reference_T	Value: 298.15 Type: Temperature (K) Description: Reference temperature of Medium: default 25 deg Celsius
reference_X	Value: fill(1 / nX, nX) Type: MassFraction[nX] (kg/kg) Description: Default mass fractions of medium
p_default	Value: 101325 Type: AbsolutePressure (Pa) Description: Default value for pressure of medium (for initialization)
T_default	Value: Modelica.Units.Conversions.from_degC(20) Type: Temperature (K) Description: Default value for temperature of medium (for initialization)
h_default	Value: specificEnthalpy_pTX(p_default, T_default, X_default) Type: SpecificEnthalpy (J/kg) Description: Default value for specific enthalpy of medium (for initialization)
X_default	Value: reference_X Type: MassFraction[nX] (kg/kg) Description: Default value for mass fractions of medium (for initialization)
C_default	Value: fill(0, nC) Type: ExtraProperty[nC] Description: Default value for trace substances of medium (for initialization)
nS	Value: size(substanceNames, 1) Type: Integer Description: Number of substances
nX	Value: nS Type: Integer Description: Number of mass fractions
nXi	Value: if fixedX then 0 else if reducedX then nS - 1 else nS Type: Integer Description: Number of structurally independent mass fractions (see docu for details)
nC	Value: size(extraPropertiesNames, 1) Type: Integer Description: Number of extra (outside of standard mass-balance) transported properties
C_nominal	Value: 1.0e-6 * ones(nC) Type: Real[nC] Description: Default for the nominal values for the extra properties
data	Value: Type: DataRecord Description: Data record of ideal gas substance
fluidConstants	Value: Type: FluidConstants[nS] Description: Constant data for the fluid

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

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.

Wolfram Language

In[1]:=

SystemModel["Modelica.Media.IdealGases.Common.SingleGasNasa"]

Out[1]:=

Extended by (38)

	SO3 Modelica.Media.IdealGases.SingleGases Ideal gas "SO3" from NASA Glenn coefficients
	SO2 Modelica.Media.IdealGases.SingleGases Ideal gas "SO2" from NASA Glenn coefficients
	O2 Modelica.Media.IdealGases.SingleGases Ideal gas "O2" from NASA Glenn coefficients
	Ne Modelica.Media.IdealGases.SingleGases Ideal gas "Ne" from NASA Glenn coefficients
	N2O Modelica.Media.IdealGases.SingleGases Ideal gas "N2O" from NASA Glenn coefficients
	N2 Modelica.Media.IdealGases.SingleGases Ideal gas "N2" from NASA Glenn coefficients
	NO2 Modelica.Media.IdealGases.SingleGases Ideal gas "NO2" from NASA Glenn coefficients
	NO Modelica.Media.IdealGases.SingleGases Ideal gas "NO" from NASA Glenn coefficients
	NH3 Modelica.Media.IdealGases.SingleGases Ideal gas "NH3" from NASA Glenn coefficients
	He Modelica.Media.IdealGases.SingleGases Ideal gas "He" from NASA Glenn coefficients
	H2O Modelica.Media.IdealGases.SingleGases Ideal gas "H2O" from NASA Glenn coefficients
	H2 Modelica.Media.IdealGases.SingleGases Ideal gas "H2" from NASA Glenn coefficients
	F2 Modelica.Media.IdealGases.SingleGases Ideal gas "F2" from NASA Glenn coefficients
	CL2 Modelica.Media.IdealGases.SingleGases Ideal gas "Cl2" from NASA Glenn coefficients
	C8H18_n_octane Modelica.Media.IdealGases.SingleGases Ideal gas "C8H18_n_octane" from NASA Glenn coefficients
	C8H10_ethylbenz Modelica.Media.IdealGases.SingleGases Ideal gas "C8H10_ethylbenz" from NASA Glenn coefficients
	C7H16_n_heptane Modelica.Media.IdealGases.SingleGases Ideal gas "C7H16_n_heptane" from NASA Glenn coefficients
	C7H14_1_heptene Modelica.Media.IdealGases.SingleGases Ideal gas "C7H14_1_heptene" from NASA Glenn coefficients
	C6H14_n_hexane Modelica.Media.IdealGases.SingleGases Ideal gas "C6H14_n_hexane" from NASA Glenn coefficients
	C6H12_1_hexene Modelica.Media.IdealGases.SingleGases Ideal gas "C6H12_1_hexene" from NASA Glenn coefficients
	C6H6 Modelica.Media.IdealGases.SingleGases Ideal gas "C6H6" from NASA Glenn coefficients
	C5H12_n_pentane Modelica.Media.IdealGases.SingleGases Ideal gas "C5H12_n_pentane" from NASA Glenn coefficients
	C5H10_1_pentene Modelica.Media.IdealGases.SingleGases Ideal gas "C5H10_1_pentene" from NASA Glenn coefficients
	C4H10_n_butane Modelica.Media.IdealGases.SingleGases Ideal gas "C4H10_n_butane" from NASA Glenn coefficients
	C4H8_1_butene Modelica.Media.IdealGases.SingleGases Ideal gas "C4H8_1_butene" from NASA Glenn coefficients
	C3H8O_1propanol Modelica.Media.IdealGases.SingleGases Ideal gas "C3H8O_1propanol" from NASA Glenn coefficients
	C3H8 Modelica.Media.IdealGases.SingleGases Ideal gas "C3H8" from NASA Glenn coefficients
	C3H6_propylene Modelica.Media.IdealGases.SingleGases Ideal gas "C3H6_propylene" from NASA Glenn coefficients
	C2H6 Modelica.Media.IdealGases.SingleGases Ideal gas "C2H6" from NASA Glenn coefficients
	C2H5OH Modelica.Media.IdealGases.SingleGases Ideal gas "C2H5OH" from NASA Glenn coefficients
	C2H4 Modelica.Media.IdealGases.SingleGases Ideal gas "C2H4" from NASA Glenn coefficients
	C2H2_vinylidene Modelica.Media.IdealGases.SingleGases Ideal gas "C2H2_vinylidene" from NASA Glenn coefficients
	CO2 Modelica.Media.IdealGases.SingleGases Ideal gas "CO2" from NASA Glenn coefficients
	CO Modelica.Media.IdealGases.SingleGases Ideal gas "CO" from NASA Glenn coefficients
	CH3OH Modelica.Media.IdealGases.SingleGases Ideal gas "CH3OH" from NASA Glenn coefficients
	CH4 Modelica.Media.IdealGases.SingleGases Ideal gas "CH4" from NASA Glenn coefficients
	Ar Modelica.Media.IdealGases.SingleGases Ideal gas "Ar" from NASA Glenn coefficients
	DryAirNasa Modelica.Media.Air Air: Detailed dry air model as ideal gas (200..6000 K)

Enable JavaScript to interact with content and submit forms on Wolfram websites. Learn how »