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: 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.
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) |