WOLFRAM SYSTEMMODELER

BaseProperties

Base properties (p, d, T, h, u, R, MM and, if applicable, X and Xi) of a medium

Wolfram Language

In[1]:=
SystemModel["Modelica.Media.Interfaces.PartialMedium.BaseProperties"]
Out[1]:=

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Model BaseProperties is a model within package PartialMedium and contains the declarations of the minimum number of variables that every medium model is supposed to support. A specific medium inherits from model BaseProperties and provides the equations for the basic properties.

The BaseProperties model contains the following 7+nXi variables (nXi is the number of independent mass fractions defined in package PartialMedium):

Variable Unit Description
T K temperature
p Pa absolute pressure
d kg/m3 density
h J/kg specific enthalpy
u J/kg specific internal energy
Xi[nXi] kg/kg independent mass fractions m_i/m
R J/kg.K gas constant
M kg/mol molar mass

In order to implement an actual medium model, one can extend from this base model and add 5 equations that provide relations among these variables. Equations will also have to be added in order to set all the variables within the ThermodynamicState record state.

If standardOrderComponents=true, the full composition vector X[nX] is determined by the equations contained in this base class, depending on the independent mass fraction vector Xi[nXi].

Additional 2 + nXi equations will have to be provided when using the BaseProperties model, in order to fully specify the thermodynamic conditions. The input connector qualifier applied to p, h, and nXi indirectly declares the number of missing equations, permitting advanced equation balance checking by Modelica tools. Please note that this doesn't mean that the additional equations should be connection equations, nor that exactly those variables should be supplied, in order to complete the model. For further information, see the Modelica.Media User's guide, and Section 4.7 (Balanced Models) of the Modelica 3.0 specification.

Parameters (2)

preferredMediumStates

Value: false

Type: Boolean

Description: = true if StateSelect.prefer shall be used for the independent property variables of the medium

standardOrderComponents

Value: true

Type: Boolean

Description: If true, and reducedX = true, the last element of X will be computed from the other ones

Connectors (3)

p

Type: InputAbsolutePressure

Description: Absolute pressure of medium

Xi

Type: InputMassFraction[nXi]

Description: Structurally independent mass fractions

h

Type: InputSpecificEnthalpy

Description: Specific enthalpy of medium

Components (1)

state

Type: ThermodynamicState

Description: Thermodynamic state record for optional functions

Used in Components (10)

PartialSource

Modelica.Fluid.Sources.BaseClasses

Partial component source with one fluid connector

PartialFlowSource

Modelica.Fluid.Sources.BaseClasses

Partial component source with one fluid connector

PartialLumpedVolume

Modelica.Fluid.Interfaces

Lumped volume with mass and energy balance

PartialDistributedVolume

Modelica.Fluid.Interfaces

Base class for distributed volume models

PortVolume

Modelica.Media.Examples.Utilities

Fixed volume associated with a port by the finite volume method

FixedMassFlowRate

Modelica.Media.Examples.Utilities

Ideal pump that produces a constant mass flow rate from a large reservoir at fixed temperature and mass fraction

FixedAmbient

Modelica.Media.Examples.Utilities

Ambient pressure, temperature and mass fraction source

PortVolume

Modelica.Media.Examples.Tests.Components

Fixed volume associated with a port by the finite volume method

FixedMassFlowRate

Modelica.Media.Examples.Tests.Components

Ideal pump that produces a constant mass flow rate from a large reservoir at fixed temperature and mass fraction

FixedAmbient

Modelica.Media.Examples.Tests.Components

Ambient pressure, temperature and mass fraction source

Extended by (3)

BaseProperties

Modelica.Media.Incompressible.TableBased

Base properties of T dependent medium

BaseProperties

Modelica.Media.Interfaces.PartialPureSubstance

BaseProperties

Modelica.Media.Interfaces.TemplateMedium

Base properties of medium