Partial medium properties (base package of all media packages)
Information
PartialMedium is a package and contains all declarations for
a medium. This means that constants, models, and functions
are defined that every medium is supposed to support
(some of them are optional). A medium package
inherits from PartialMedium and provides the
equations for the medium. The details of this package
are described in
Modelica.Media.UsersGuide.
Extends from Modelica.Media.Interfaces.Types (Types to be used in fluid models), Modelica.Icons.MaterialPropertiesPackage (Icon for package containing property classes).
Package Content
| Name |
Description |
| ThermoStates |
Enumeration type for independent variables |
| mediumName="unusablePartialMedium" |
Name of the medium |
| substanceNames={mediumName} |
Names of the mixture substances. Set substanceNames={mediumName} if only one substance. |
| extraPropertiesNames=fill("", 0) |
Names of the additional (extra) transported properties. Set extraPropertiesNames=fill("",0) if unused |
| singleState |
= true, if u and d are not a function of pressure |
| reducedX=true |
= true if medium contains the equation sum(X) = 1.0; set reducedX=true if only one substance (see docu for details) |
| fixedX=false |
= true if medium contains the equation X = reference_X |
| reference_p=101325 |
Reference pressure of Medium: default 1 atmosphere |
| reference_T=298.15 |
Reference temperature of Medium: default 25 deg Celsius |
| reference_X=fill(1/nX, nX) |
Default mass fractions of medium |
| p_default=101325 |
Default value for pressure of medium (for initialization) |
| T_default=Modelica.Units.Conversions.from_degC(20) |
Default value for temperature of medium (for initialization) |
| h_default=specificEnthalpy_pTX(p_default, T_default, X_default) |
Default value for specific enthalpy of medium (for initialization) |
| X_default=reference_X |
Default value for mass fractions of medium (for initialization) |
| C_default=fill(0, nC) |
Default value for trace substances of medium (for initialization) |
| nS=size(substanceNames, 1) |
Number of substances |
| nX=nS |
Number of mass fractions |
| nXi=if fixedX then 0 else if reducedX then nS - 1 else nS |
Number of structurally independent mass fractions (see docu for details) |
| nC=size(extraPropertiesNames, 1) |
Number of extra (outside of standard mass-balance) transported properties |
| C_nominal=1.0e-6*ones(nC) |
Default for the nominal values for the extra properties |
 FluidConstants
|
Critical, triple, molecular and other standard data of fluid |
| ThermodynamicState
|
Minimal variable set that is available as input argument to every medium function |
 BaseProperties
|
Base properties (p, d, T, h, u, R_s, MM and, if applicable, X and Xi) of a medium |
 setState_pTX
|
Return thermodynamic state as function of p, T and composition X or Xi |
| setState_phX
|
Return thermodynamic state as function of p, h and composition X or Xi |
| setState_psX
|
Return thermodynamic state as function of p, s and composition X or Xi |
| setState_dTX
|
Return thermodynamic state as function of d, T and composition X or Xi |
| setSmoothState
|
Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b |
| dynamicViscosity
|
Return dynamic viscosity |
| thermalConductivity
|
Return thermal conductivity |
| prandtlNumber
|
Return the Prandtl number |
| pressure
|
Return pressure |
| temperature
|
Return temperature |
| density
|
Return density |
| 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 |
 heatCapacity_cp
|
Alias for deprecated name |
| specificHeatCapacityCv
|
Return specific heat capacity at constant volume |
| heatCapacity_cv
|
Alias for deprecated name |
| isentropicExponent
|
Return isentropic exponent |
| isentropicEnthalpy
|
Return isentropic enthalpy |
| velocityOfSound
|
Return velocity of sound |
| isobaricExpansionCoefficient
|
Return overall the isobaric expansion coefficient beta |
| beta
|
Alias for isobaricExpansionCoefficient for user convenience |
| isothermalCompressibility
|
Return overall the isothermal compressibility factor |
| kappa
|
Alias of isothermalCompressibility for user convenience |
| density_derp_h
|
Return density derivative w.r.t. pressure at const specific enthalpy |
| density_derh_p
|
Return density derivative w.r.t. specific enthalpy at constant pressure |
| density_derp_T
|
Return density derivative w.r.t. pressure at const temperature |
| density_derT_p
|
Return density derivative w.r.t. temperature at constant pressure |
| density_derX
|
Return density derivative w.r.t. mass fraction |
| molarMass
|
Return the molar mass of the medium |
| specificEnthalpy_pTX
|
Return specific enthalpy from p, T, and X or Xi |
| specificEntropy_pTX
|
Return specific enthalpy from p, T, and X or Xi |
| density_pTX
|
Return density from p, T, and X or Xi |
| temperature_phX
|
Return temperature from p, h, and X or Xi |
| density_phX
|
Return density from p, h, and X or Xi |
| temperature_psX
|
Return temperature from p,s, and X or Xi |
| density_psX
|
Return density from p, s, and X or Xi |
| specificEnthalpy_psX
|
Return specific enthalpy from p, s, and X or Xi |
 MassFlowRate
|
Type for mass flow rate with medium specific attributes |
| Inherited |
| AbsolutePressure
|
Type for absolute pressure with medium specific attributes |
| Density
|
Type for density with medium specific attributes |
| DynamicViscosity
|
Type for dynamic viscosity with medium specific attributes |
| EnthalpyFlowRate
|
Type for enthalpy flow rate with medium specific attributes |
| MassFraction
|
Type for mass fraction with medium specific attributes |
| MoleFraction
|
Type for mole fraction with medium specific attributes |
| MolarMass
|
Type for molar mass with medium specific attributes |
| MolarVolume
|
Type for molar volume with medium specific attributes |
| IsentropicExponent
|
Type for isentropic exponent with medium specific attributes |
| SpecificEnergy
|
Type for specific energy with medium specific attributes |
| SpecificInternalEnergy
|
Type for specific internal energy with medium specific attributes |
| SpecificEnthalpy
|
Type for specific enthalpy with medium specific attributes |
| SpecificEntropy
|
Type for specific entropy with medium specific attributes |
| SpecificHeatCapacity
|
Type for specific heat capacity with medium specific attributes |
| SurfaceTension
|
Type for surface tension with medium specific attributes |
| Temperature
|
Type for temperature with medium specific attributes |
| ThermalConductivity
|
Type for thermal conductivity with medium specific attributes |
| PrandtlNumber
|
Type for Prandtl number with medium specific attributes |
| VelocityOfSound
|
Type for velocity of sound with medium specific attributes |
| ExtraProperty
|
Type for unspecified, mass-specific property transported by flow |
| CumulativeExtraProperty
|
Type for conserved integral of unspecified, mass specific property |
| ExtraPropertyFlowRate
|
Type for flow rate of unspecified, mass-specific property |
| IsobaricExpansionCoefficient
|
Type for isobaric expansion coefficient with medium specific attributes |
| DipoleMoment
|
Type for dipole moment with medium specific attributes |
| DerDensityByPressure
|
Type for partial derivative of density with respect to pressure with medium specific attributes |
| DerDensityByEnthalpy
|
Type for partial derivative of density with respect to enthalpy with medium specific attributes |
| DerEnthalpyByPressure
|
Type for partial derivative of enthalpy with respect to pressure with medium specific attributes |
| DerDensityByTemperature
|
Type for partial derivative of density with respect to temperature with medium specific attributes |
| DerTemperatureByPressure
|
Type for partial derivative of temperature with respect to pressure with medium specific attributes |
 SaturationProperties
|
Saturation properties of two phase medium |
| FluidLimits
|
Validity limits for fluid model |
 FixedPhase
|
Phase of the fluid: 1 for 1-phase, 2 for two-phase, 0 for not known, e.g., interactive use |
 Basic
|
The most basic version of a record used in several degrees of detail |
| IdealGas
|
The ideal gas version of a record used in several degrees of detail |
| TwoPhase
|
The two phase fluid version of a record used in several degrees of detail |
Critical, triple, molecular and other standard data of fluid
Minimal variable set that is available as input argument to every medium function
Information
Extends from Modelica.Icons.Record (Icon for records).
Base properties (p, d, T, h, u, R_s, MM and, if applicable, X and Xi) of a medium
Information
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 |
Structurally independent mass fractions |
| R_s |
J/(kg.K) |
Specific gas constant (of mixture if applicable) |
| MM |
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 3.4 specification.
Parameters
| Name | Description |
|---|
| standardOrderComponents | If true, and reducedX = true, the last element of X will be computed from the other ones |
| Advanced |
| preferredMediumStates | = true if StateSelect.prefer shall be used for the independent property variables of the medium |
Return thermodynamic state as function of p, T and composition X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| state | Thermodynamic state record |
Return thermodynamic state as function of p, h and composition X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| state | Thermodynamic state record |
Return thermodynamic state as function of p, s and composition X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| state | Thermodynamic state record |
Return thermodynamic state as function of d, T and composition X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| state | Thermodynamic state record |
Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b
Information
This function is used to approximate the equation
state = if x > 0 then state_a else state_b;
by a smooth characteristic, so that the expression is continuous and differentiable:
state := smooth(1, if x > x_small then state_a else
if x < -x_small then state_b else f(state_a, state_b));
This is performed by applying function Media.Common.smoothStep(..)
on every element of the thermodynamic state record.
If mass fractions X[:] are approximated with this function then this can be performed
for all nX mass fractions, instead of applying it for nX-1 mass fractions and computing
the last one by the mass fraction constraint sum(X)=1. The reason is that the approximating function has the
property that sum(state.X) = 1, provided sum(state_a.X) = sum(state_b.X) = 1.
This can be shown by evaluating the approximating function in the abs(x) < x_small
region (otherwise state.X is either state_a.X or state_b.X):
X[1] = smoothStep(x, X_a[1] , X_b[1] , x_small);
X[2] = smoothStep(x, X_a[2] , X_b[2] , x_small);
...
X[nX] = smoothStep(x, X_a[nX], X_b[nX], x_small);
or
X[1] = c*(X_a[1] - X_b[1]) + (X_a[1] + X_b[1])/2
X[2] = c*(X_a[2] - X_b[2]) + (X_a[2] + X_b[2])/2;
...
X[nX] = c*(X_a[nX] - X_b[nX]) + (X_a[nX] + X_b[nX])/2;
c = (x/x_small)*((x/x_small)^2 - 3)/4
Summing all mass fractions together results in
sum(X) = c*(sum(X_a) - sum(X_b)) + (sum(X_a) + sum(X_b))/2
= c*(1 - 1) + (1 + 1)/2
= 1
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| state | Smooth thermodynamic state for all x (continuous and differentiable) |
Return dynamic viscosity
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| eta | Dynamic viscosity [Pa.s] |
Return thermal conductivity
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| lambda | Thermal conductivity [W/(m.K)] |
Return the Prandtl number
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| Pr | Prandtl number [1] |
Return pressure
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| p | Pressure [Pa] |
Return temperature
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| T | Temperature [K] |
Return density
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| d | Density [kg/m3] |
Return specific enthalpy
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| h | Specific enthalpy [J/kg] |
Return specific internal energy
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| u | Specific internal energy [J/kg] |
Return specific entropy
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| s | Specific entropy [J/(kg.K)] |
Return specific Gibbs energy
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| g | Specific Gibbs energy [J/kg] |
Return specific Helmholtz energy
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| f | Specific Helmholtz energy [J/kg] |
Return specific heat capacity at constant pressure
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| cp | Specific heat capacity at constant pressure [J/(kg.K)] |
Alias for deprecated name
Inputs
Outputs
| Name | Description |
|---|
| cp | Specific heat capacity at constant pressure [J/(kg.K)] |
Return specific heat capacity at constant volume
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| cv | Specific heat capacity at constant volume [J/(kg.K)] |
Alias for deprecated name
Inputs
Outputs
| Name | Description |
|---|
| cv | Specific heat capacity at constant volume [J/(kg.K)] |
Return isentropic exponent
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| gamma | Isentropic exponent [1] |
Return isentropic enthalpy
Information
This function computes an isentropic state transformation:
- A medium is in a particular state, refState.
- The enthalpy at another state (h_is) shall be computed
under the assumption that the state transformation from refState to h_is
is performed with a change of specific entropy ds = 0 and the pressure of state h_is
is p_downstream and the composition X upstream and downstream is assumed to be the same.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| h_is | Isentropic enthalpy [J/kg] |
Return velocity of sound
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| a | Velocity of sound [m/s] |
Return overall the isobaric expansion coefficient beta
Information
beta is defined as 1/v * der(v,T), with v = 1/d, at constant pressure p.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| beta | Isobaric expansion coefficient [1/K] |
Alias for isobaricExpansionCoefficient for user convenience
Inputs
Outputs
| Name | Description |
|---|
| beta | Isobaric expansion coefficient [1/K] |
Return overall the isothermal compressibility factor
Information
kappa is defined as - 1/v * der(v,p), with v = 1/d at constant temperature T.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| kappa | Isothermal compressibility [1/Pa] |
Alias of isothermalCompressibility for user convenience
Inputs
Outputs
| Name | Description |
|---|
| kappa | Isothermal compressibility [1/Pa] |
Return density derivative w.r.t. pressure at const specific enthalpy
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| ddph | Density derivative w.r.t. pressure [s2/m2] |
Return density derivative w.r.t. specific enthalpy at constant pressure
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| ddhp | Density derivative w.r.t. specific enthalpy [kg.s2/m5] |
Return density derivative w.r.t. pressure at const temperature
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| ddpT | Density derivative w.r.t. pressure [s2/m2] |
Return density derivative w.r.t. temperature at constant pressure
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| ddTp | Density derivative w.r.t. temperature [kg/(m3.K)] |
Return density derivative w.r.t. mass fraction
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| dddX[nX] | Derivative of density w.r.t. mass fraction [kg/m3] |
Return the molar mass of the medium
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| MM | Mixture molar mass [kg/mol] |
Return specific enthalpy from p, T, and X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| h | Specific enthalpy [J/kg] |
Return specific enthalpy from p, T, and X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| s | Specific entropy [J/(kg.K)] |
Return density from p, T, and X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| d | Density [kg/m3] |
Return temperature from p, h, and X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| T | Temperature [K] |
Return density from p, h, and X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| d | Density [kg/m3] |
Return temperature from p,s, and X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| T | Temperature [K] |
Return density from p, s, and X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| d | Density [kg/m3] |
Return specific enthalpy from p, s, and X or Xi
Information
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Outputs
| Name | Description |
|---|
| h | Specific enthalpy [J/kg] |
Type for mass flow rate with medium specific attributes
Parameters
| Name | Value |
|---|
| Custom Parameters |
| quantity | "MassFlowRate." + mediumName |
| min | -1.0e5 |
| max | 1.e5 |
Automatically generated Thu Oct 1 16:08:01 2020.
Modelica.Media.Interfaces.PartialMedium.FluidConstants
Modelica.Media.Interfaces.PartialMedium.BaseProperties
Modelica.Media.Interfaces.PartialMedium.setState_pTX