WOLFRAM SYSTEM MODELER

Medium

Medium model

Package Constants (27)

ThermoStates

Value: Modelica.Media.Interfaces.Choices.IndependentVariables.pTX

Type: IndependentVariables

Description: Enumeration type for independent variables

mediumName

Value: "Moist air"

Type: String

Description: Name of the medium

substanceNames

Value: {"water", "air"}

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: false

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: {0.01, 0.99}

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

fluidConstants

Value: {IdealGases.Common.FluidData.H2O, IdealGases.Common.FluidData.N2}

Type: FluidConstants[nS]

Description: Constant data for the fluid

Water

Value: 1

Type: Integer

Description: Index of water (in substanceNames, massFractions X, etc.)

Air

Value: 2

Type: Integer

Description: Index of air (in substanceNames, massFractions X, etc.)

k_mair

Value: steam.MM / dryair.MM

Type: Real

Description: Ratio of molar weights

dryair

Value: IdealGases.Common.SingleGasesData.Air

Type: DataRecord

Description: Coefficient data record for properties of ideal gases based on NASA source

steam

Value: IdealGases.Common.SingleGasesData.H2O

Type: DataRecord

Description: Coefficient data record for properties of ideal gases based on NASA source

MMX

Value: {steam.MM, dryair.MM}

Type: MolarMass[2] (kg/mol)

Description: Molar masses of components

Wolfram Language

In[1]:=
SystemModel["Modelica.Media.Examples.MoistAir.Medium"]
Out[1]:=