Medium model of Ideal gas with constant cp and cv. All other quantities, e.g., transport properties, are constant.
density
,
specificEntropy
and setState_dTX
are declared as replaceable
.
This is required for the implementation of
Buildings.Obsolete.Media.GasesPTDecoupled.SimpleAir.
Extends from Modelica.Media.Interfaces.PartialPureSubstance (Base class for pure substances of one chemical substance).
Name | Description |
---|---|
cp_const | Constant specific heat capacity at constant pressure |
cv_const=cp_const - R_gas | Constant specific heat capacity at constant volume |
R_gas | medium specific gas constant |
MM_const | Molar mass |
eta_const | Constant dynamic viscosity |
lambda_const | Constant thermal conductivity |
T_min | Minimum temperature valid for medium model |
T_max | Maximum temperature valid for medium model |
T0=reference_T | Zero enthalpy temperature |
ThermodynamicState | Thermodynamic state of ideal gas |
FluidConstants | fluid constants |
BaseProperties | Base properties of ideal gas |
setState_pTX | Return thermodynamic state from p, T, and X or Xi |
setState_phX | Return thermodynamic state from p, h, and X or Xi |
setState_psX | Return thermodynamic state from p, s, and X or Xi |
setState_dTX | Return thermodynamic state from d, T, and X or Xi |
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 |
dynamicViscosity | Return dynamic viscosity |
thermalConductivity | Return thermal conductivity |
specificHeatCapacityCp | Return specific heat capacity at constant pressure |
specificHeatCapacityCv | Return specific heat capacity at constant volume |
isentropicExponent | Return isentropic exponent |
velocityOfSound | Return velocity of sound |
specificEnthalpy_pTX | Return specific enthalpy 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 |
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 |
molarMass | Returns the molar mass of the medium |
Inherited | |
setState_pT | Return thermodynamic state from p and T |
setState_ph | Return thermodynamic state from p and h |
setState_ps | Return thermodynamic state from p and s |
setState_dT | Return thermodynamic state from d and T |
density_ph | Return density from p and h |
temperature_ph | Return temperature from p and h |
pressure_dT | Return pressure from d and T |
specificEnthalpy_dT | Return specific enthalpy from d and T |
specificEnthalpy_ps | Return specific enthalpy from p and s |
temperature_ps | Return temperature from p and s |
density_ps | Return density from p and s |
specificEnthalpy_pT | Return specific enthalpy from p and T |
density_pT | Return density from p and T |
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.SIunits.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) |
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 |
prandtlNumber | Return the Prandtl number |
heatCapacity_cp | Alias for deprecated name |
heatCapacity_cv | Alias for deprecated name |
beta | Alias for isobaricExpansionCoefficient for user convenience |
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 |
specificEntropy_pTX | Return specific enthalpy from p, T, and X or Xi |
density_pTX | Return density from p, T, 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 |
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 |
constant SpecificHeatCapacity cp_const "Constant specific heat capacity at constant pressure";
constant SpecificHeatCapacity cv_const= cp_const - R_gas "Constant specific heat capacity at constant volume";
constant SpecificHeatCapacity R_gas "medium specific gas constant";
constant MolarMass MM_const "Molar mass";
constant DynamicViscosity eta_const "Constant dynamic viscosity";
constant ThermalConductivity lambda_const "Constant thermal conductivity";
constant Temperature T_min "Minimum temperature valid for medium model";
constant Temperature T_max "Maximum temperature valid for medium model";
constant Temperature T0= reference_T "Zero enthalpy temperature";
Thermodynamic state of ideal gas
Extends from (Minimal variable set that is available as input argument to every medium function).
fluid constants
Extends from (Critical, triple, molecular and other standard data of fluid).
Base properties of ideal gas
This is the most simple incompressible medium model, where specific enthalpy h and specific internal energy u are only a function of temperature T and all other provided medium quantities are assumed to be constant.
Type | Name | Default | Description |
---|---|---|---|
Advanced | |||
Boolean | preferredMediumStates | false | = true if StateSelect.prefer shall be used for the independent property variables of the medium |
Return thermodynamic state from p, T, and X or Xi
Extends from Modelica.Icons.Function (Icon for functions).
Type | Name | Default | Description |
---|---|---|---|
AbsolutePressure | p | Pressure [Pa] | |
Temperature | T | Temperature [K] | |
MassFraction | X[:] | reference_X | Mass fractions [kg/kg] |
Type | Name | Description |
---|---|---|
ThermodynamicState | state | thermodynamic state record |
Return thermodynamic state from p, h, and X or Xi
Extends from Modelica.Icons.Function (Icon for functions).
Type | Name | Default | Description |
---|---|---|---|
AbsolutePressure | p | Pressure [Pa] | |
SpecificEnthalpy | h | Specific enthalpy [J/kg] | |
MassFraction | X[:] | reference_X | Mass fractions [kg/kg] |
Type | Name | Description |
---|---|---|
ThermodynamicState | state | thermodynamic state record |
Return thermodynamic state from p, s, and X or Xi
Extends from Modelica.Icons.Function (Icon for functions).
Type | Name | Default | Description |
---|---|---|---|
AbsolutePressure | p | Pressure [Pa] | |
SpecificEntropy | s | Specific entropy [J/(kg.K)] | |
MassFraction | X[:] | reference_X | Mass fractions [kg/kg] |
Type | Name | Description |
---|---|---|
ThermodynamicState | state | thermodynamic state record |
Return thermodynamic state from d, T, and X or Xi
Extends from Modelica.Icons.Function (Icon for functions).
Type | Name | Default | Description |
---|---|---|---|
Density | d | density [kg/m3] | |
Temperature | T | Temperature [K] | |
MassFraction | X[:] | reference_X | Mass fractions [kg/kg] |
Type | Name | Description |
---|---|---|
ThermodynamicState | state | thermodynamic state record |
Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b
Extends from (Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b).
Type | Name | Default | Description |
---|---|---|---|
Real | x | m_flow or dp | |
ThermodynamicState | state_a | Thermodynamic state if x > 0 | |
ThermodynamicState | state_b | Thermodynamic state if x < 0 | |
Real | x_small | Smooth transition in the region -x_small < x < x_small |
Type | Name | Description |
---|---|---|
ThermodynamicState | state | Smooth thermodynamic state for all x (continuous and differentiable) |
Return pressure of ideal gas
Extends from (Return pressure).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
AbsolutePressure | p | Pressure [Pa] |
Return temperature of ideal gas
Extends from (Return temperature).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
Temperature | T | Temperature [K] |
Return density of ideal gas
Extends from (Return density).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
Density | d | Density [kg/m3] |
Return specific enthalpy
Extends from Modelica.Icons.Function (Icon for functions), (Return specific enthalpy).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
SpecificEnthalpy | h | Specific enthalpy [J/kg] |
Return specific internal energy
Extends from Modelica.Icons.Function (Icon for functions), (Return specific internal energy).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
SpecificEnergy | u | Specific internal energy [J/kg] |
Return specific entropy
Extends from Modelica.Icons.Function (Icon for functions), (Return specific entropy).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
SpecificEntropy | s | Specific entropy [J/(kg.K)] |
Return specific Gibbs energy
Extends from Modelica.Icons.Function (Icon for functions), (Return specific Gibbs energy).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
SpecificEnergy | g | Specific Gibbs energy [J/kg] |
Return specific Helmholtz energy
Extends from Modelica.Icons.Function (Icon for functions), (Return specific Helmholtz energy).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
SpecificEnergy | f | Specific Helmholtz energy [J/kg] |
Return dynamic viscosity
Extends from (Return dynamic viscosity).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
DynamicViscosity | eta | Dynamic viscosity [Pa.s] |
Return thermal conductivity
Extends from (Return thermal conductivity).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
ThermalConductivity | lambda | Thermal conductivity [W/(m.K)] |
Return specific heat capacity at constant pressure
Extends from (Return specific heat capacity at constant pressure).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
SpecificHeatCapacity | cp | Specific heat capacity at constant pressure [J/(kg.K)] |
Return specific heat capacity at constant volume
Extends from (Return specific heat capacity at constant volume).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
SpecificHeatCapacity | cv | Specific heat capacity at constant volume [J/(kg.K)] |
Return isentropic exponent
Extends from (Return isentropic exponent).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
IsentropicExponent | gamma | Isentropic exponent [1] |
Return velocity of sound
Extends from (Return velocity of sound).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
VelocityOfSound | a | Velocity of sound [m/s] |
Return specific enthalpy from p, T, and X or Xi
Extends from Modelica.Icons.Function (Icon for functions).
Type | Name | Default | Description |
---|---|---|---|
AbsolutePressure | p | Pressure [Pa] | |
Temperature | T | Temperature [K] | |
MassFraction | X[nX] | Mass fractions [kg/kg] |
Type | Name | Description |
---|---|---|
SpecificEnthalpy | h | Specific enthalpy at p, T, X [J/kg] |
Return temperature from p, h, and X or Xi
Extends from Modelica.Icons.Function (Icon for functions).
Type | Name | Default | Description |
---|---|---|---|
AbsolutePressure | p | Pressure [Pa] | |
SpecificEnthalpy | h | Specific enthalpy [J/kg] | |
MassFraction | X[nX] | Mass fractions [kg/kg] |
Type | Name | Description |
---|---|---|
Temperature | T | Temperature [K] |
Return density from p, h, and X or Xi
Extends from Modelica.Icons.Function (Icon for functions).
Type | Name | Default | Description |
---|---|---|---|
AbsolutePressure | p | Pressure [Pa] | |
SpecificEnthalpy | h | Specific enthalpy [J/kg] | |
MassFraction | X[nX] | Mass fractions [kg/kg] |
Type | Name | Description |
---|---|---|
Density | d | density [kg/m3] |
Return isentropic enthalpy
Extends from (Return isentropic enthalpy).
Type | Name | Default | Description |
---|---|---|---|
AbsolutePressure | p_downstream | Downstream pressure [Pa] | |
ThermodynamicState | refState | Reference state for entropy |
Type | Name | Description |
---|---|---|
SpecificEnthalpy | h_is | Isentropic enthalpy [J/kg] |
Returns overall the isobaric expansion coefficient beta
Extends from (Return overall the isobaric expansion coefficient beta).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
IsobaricExpansionCoefficient | beta | Isobaric expansion coefficient [1/K] |
Returns overall the isothermal compressibility factor
Extends from (Return overall the isothermal compressibility factor).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
IsothermalCompressibility | kappa | Isothermal compressibility [1/Pa] |
Returns the partial derivative of density with respect to pressure at constant temperature
Extends from (Return density derivative w.r.t. pressure at const temperature).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
DerDensityByPressure | ddpT | Density derivative w.r.t. pressure [s2/m2] |
Returns the partial derivative of density with respect to temperature at constant pressure
Extends from (Return density derivative w.r.t. temperature at constant pressure).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
DerDensityByTemperature | ddTp | Density derivative w.r.t. temperature [kg/(m3.K)] |
Returns the partial derivative of density with respect to mass fractions at constant pressure and temperature
Extends from (Return density derivative w.r.t. mass fraction).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
Density | dddX[nX] | Derivative of density w.r.t. mass fraction [kg/m3] |
Returns the molar mass of the medium
Extends from (Return the molar mass of the medium).
Type | Name | Default | Description |
---|---|---|---|
ThermodynamicState | state | Thermodynamic state record |
Type | Name | Description |
---|---|---|
MolarMass | MM | Mixture molar mass [kg/mol] |