.Modelica.Media.IdealGases.Common.SingleGasNasa

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.

Contents

Name Description
 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)

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