WOLFRAM SYSTEM MODELER
SingleGasNasaMedium model of an ideal gas based on NASA source |
Thermodynamic state variables for ideal gases |
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Base properties of ideal gas medium |
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Return thermodynamic state as function of p, T and composition X |
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Return thermodynamic state as function of p, h and composition X |
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Return thermodynamic state as function of p, s and composition X |
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Return thermodynamic state as function of d, T and composition X |
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Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b |
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Return pressure of ideal gas |
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Return temperature of ideal gas |
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Return density of ideal gas |
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Return specific enthalpy |
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Return specific internal energy |
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Return specific entropy |
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Return specific Gibbs energy |
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Return specific Helmholtz energy |
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Return specific heat capacity at constant pressure |
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Compute specific heat capacity at constant volume from temperature and gas data |
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Return isentropic exponent |
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Return velocity of sound |
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isentropicEnthalpyApproximation Approximate method of calculating h_is from upstream properties and downstream pressure |
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Return isentropic enthalpy |
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Returns overall the isobaric expansion coefficient beta |
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Returns overall the isothermal compressibility factor |
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Returns the partial derivative of density with respect to pressure at constant temperature |
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Returns the partial derivative of density with respect to temperature at constant pressure |
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Returns the partial derivative of density with respect to mass fractions at constant pressure and temperature |
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Dynamic viscosity |
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Thermal conductivity of gas |
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Return the molar mass of the medium |
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Compute temperature from specific enthalpy |
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Compute temperature from pressure and specific entropy |
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Dynamic viscosity of low pressure gases |
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Thermal conductivity of polyatomic gases(Eucken and Modified Eucken correlation) |
ThermoStates |
Value: Modelica.Media.Interfaces.Choices.IndependentVariables.pT Type: IndependentVariables Description: Enumeration type for independent variables |
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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: redeclare record FluidConstants = Modelica.Media.Interfaces.Types.IdealGas.FluidConstants Type: FluidConstants[nS] Description: Constant data for the fluid |
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.
SystemModel["Modelica.Media.IdealGases.Common.SingleGasNasa"]
Modelica.Media.IdealGases.SingleGases Ideal gas "SO3" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "SO2" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "O2" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "Ne" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "N2O" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "N2" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "NO2" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "NO" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "NH3" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "He" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "H2O" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "H2" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "F2" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "Cl2" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C8H18_n_octane" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C8H10_ethylbenz" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C7H16_n_heptane" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C7H14_1_heptene" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C6H14_n_hexane" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C6H12_1_hexene" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C6H6" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C5H12_n_pentane" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C5H10_1_pentene" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C4H10_n_butane" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C4H8_1_butene" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C3H8O_1propanol" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C3H8" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C3H6_propylene" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C2H6" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C2H5OH" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C2H4" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "C2H2_vinylidene" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "CO2" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "CO" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "CH3OH" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "CH4" from NASA Glenn coefficients |
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Modelica.Media.IdealGases.SingleGases Ideal gas "Ar" from NASA Glenn coefficients |
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Modelica.Media.Air Air: Detailed dry air model as ideal gas (200..6000 K) |