packagePartialSimpleAlloy

Material properties based on tables

Extends from TRANSFORM.Media.Interfaces.Solids.PartialAlloy (Partial material properties (base package of all material packages)).

Information

This is the base package for medium models of incompressible fluids based on tables. The minimal data to provide for a useful medium description is tables of density and heat capacity as functions of temperature.

It should be noted that incompressible media only have 1 state per control volume (usually T), but have both T and p as inputs for fully correct properties. The error of using only T-dependent properties is small, therefore a Boolean flag enthalpyOfT exists. If it is true, the enumeration Choices.independentVariables is set to Choices.independentVariables.T otherwise it is set to Choices.independentVariables.pT.

Using the package TableBased

To implement a new medium model, create a package that extends TableBased and provides one or more of the constant tables:

tableDensity        = [T, d];
tableHeatCapacity   = [T, Cp];
tableConductivity   = [T, lam];
tableViscosity      = [T, eta];
tableVaporPressure  = [T, pVap];

The table data is used to fit constant polynomials of order npol, the temperature data points do not need to be same for different properties. Properties like enthalpy, inner energy and entropy are calculated consistently from integrals and derivatives of d(T) and Cp(T). The minimal data for a useful medium model is thus density and heat capacity. Transport properties and vapor pressure are optional, if the data tables are empty the corresponding function calls can not be used.

Parameters

TypeNameDefaultDescription
StringmediumName (from PartialAlloy)"unusablePartialMedium"Name of the medium
String[:]substanceNames (from PartialAlloy){mediumName}Names of the mixture substances. Set substanceNames={mediumName} if only one substance.
Modelica.Media.Interfaces.Types.TemperatureT_reference (from PartialAlloy)298.15Reference temperature of Medium: default 25 deg Celsius
Modelica.Media.Interfaces.Types.SpecificEnthalpyh_reference (from PartialAlloy)0Reference enthalpy at T_reference
TemperatureT_default (from PartialAlloy)293.15Default value for temperature of medium (for initialization)
SpecificEnthalpyh_default (from PartialAlloy)specificEnthalpy_T(T_default)Default value for specific enthalpy of medium (for initialization)
Modelica.SIunits.TemperatureT_minMinimum temperature valid for medium model
Modelica.SIunits.TemperatureT_maxMaximum temperature valid for medium model
MolarMassMM_const0.1Molar mass

Contents

NameDescription
ThermodynamicStateThermodynamic state
BasePropertiesBase properties of T dependent medium
setState_TReturns state record, given temperature
setSmoothStateReturn thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b
temperatureReturn temperature as a function of the thermodynamic state record
specificInternalEnergyReturn specific internal energy as a function of the thermodynamic state record
molarMassMolar mass