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