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 |
|---|---|
| Thermodynamic state | |
| Base properties of air | |
| Computes density as a function of pressure and specific enthalpy | |
| Computes temperature as a function of pressure and specific enthalpy | |
| Compute temperature from pressure and specific enthalpy | |
| Computes density as a function of pressure and specific enthalpy | |
| Computes pressure as a function of density and temperature | |
| Computes specific enthalpy as a function of density and temperature | |
| Computes specific enthalpy as a function of pressure and temperature | |
| Computes specific enthalpy as a function of pressure and temperature | |
| Computes density as a function of pressure and temperature | |
| Return dynamic viscosity as a function of the thermodynamic state record | |
| Thermal conductivity of air | |
| Return pressure of ideal gas | |
| Return temperature of ideal gas | |
| Return density of ideal gas | |
| Return specific enthalpy | |
| Return specific internal energy | |
| Return specific Gibbs energy | |
| Return specific Helmholtz energy | |
| Specific entropy of air | |
| Specific heat capacity at constant pressure of air | |
| Specific heat capacity at constant volume of air | |
| Return isentropic exponent | |
| Isothermal compressibility of air | |
| Isobaric expansion coefficient of air | |
| Return velocity of sound as a function of the thermodynamic state record | |
| Density derivative by specific enthalpy | |
| Density derivative by pressure | |
| Return thermodynamic state of air as function of d and T | |
| Return thermodynamic state of air as function of p and h | |
| Return thermodynamic state of air as function of p and s | |
| Return thermodynamic state of air as function of p and T | |
| Return thermodynamic state so that it smoothly approximates: if x > 0 then state_a else state_b | |
| Return the molar mass of the medium |