This model calculates medium properties for air in the liquid, gas and two phase regions. Three variable pairs can be the independent variables of the model:
The following quantities are always computed:
Variable | Unit | Description |
T | K | temperature |
u | J/kg | specific internal energy |
d | kg/m^3 | density |
p | Pa | pressure |
h | J/kg | specific enthalpy |
In some cases additional medium properties are needed. A component that needs these optional properties has to call one of the functions listed in Modelica.Media.UsersGuide.MediumUsage.OptionalProperties and in Modelica.Media.UsersGuide.MediumUsage.TwoPhase.
Many further properties can be computed. Using the well-known Bridgman's Tables, all first partial derivatives of the standard thermodynamic variables can be computed easily.
Name | Description |
---|---|
ThermodynamicState | Thermodynamic state |
BaseProperties | Base properties of air |
density_ph | Computes density as a function of pressure and specific enthalpy |
temperature_ph | Computes temperature as a function of pressure and specific enthalpy |
temperature_ps | Compute temperature from pressure and specific enthalpy |
density_ps | Computes density as a function of pressure and specific enthalpy |
pressure_dT | Computes pressure as a function of density and temperature |
specificEnthalpy_dT | Computes specific enthalpy as a function of density and temperature |
specificEnthalpy_pT | Computes specific enthalpy as a function of pressure and temperature |
specificEnthalpy_ps | Computes specific enthalpy as a function of pressure and temperature |
density_pT | Computes density as a function of pressure and temperature |
dynamicViscosity | Return dynamic viscosity as a function of the thermodynamic state record |
thermalConductivity | Thermal conductivity of air |
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 |
specificGibbsEnergy | Return specific Gibbs energy |
specificHelmholtzEnergy | Return specific Helmholtz energy |
specificEntropy | Specific entropy of air |
specificHeatCapacityCp | Specific heat capacity at constant pressure of air |
specificHeatCapacityCv | Specific heat capacity at constant volume of air |
isentropicExponent | Return isentropic exponent |
isothermalCompressibility | Isothermal compressibility of air |
isobaricExpansionCoefficient | Isobaric expansion coefficient of air |
velocityOfSound | Return velocity of sound as a function of the thermodynamic state record |
density_derh_p | Density derivative by specific enthalpy |
density_derp_h | Density derivative by pressure |
setState_dTX | Return thermodynamic state of air as function of d and T |
setState_phX | Return thermodynamic state of air as function of p and h |
setState_psX | Return thermodynamic state of air as function of p and s |
setState_pTX | Return thermodynamic state of air as function of p and T |
setSmoothState | Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b |
isentropicEnthalpy | |
molarMass | Return the molar mass of the medium |