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 |