**Package with models for gases where pressure and temperature are independent of each other**

### Information

Medium models in this package use the gas law
*d/d*_{stp} = p/p_{stp} where
*p*_{std} and *d*_{stp} are constants for a reference
temperature and density instead of the ideal gas law
*ρ = p ⁄(R T)*.

This new formulation often leads to smaller systems of nonlinear equations
because pressure and temperature are decoupled, at the expense of accuracy.

Note that models in this package implement the equation for the internal energy as

u = h - p_{stp} ⁄ ρ_{stp},

where
*u* is the internal energy per unit mass,
*h* is the enthalpy per unit mass,
*p*_{stp} is the static pressure and
*ρ*_{stp} is the mass density at standard pressure and temperature.
The reason for this implementation is that in general,
h = u + p v,

from which follows that
u = h - p v = h - p ⁄ ρ = h - p_{stp} ⁄ ρ_{std},

because *p ⁄ ρ = p*_{stp} ⁄ ρ_{stp} in this medium model.
Extends from Modelica.Icons.MaterialPropertiesPackage (Icon for package containing property classes).

### Package Content

Name | Description |

Examples
| Collection of models that illustrate model use and test models |

MoistAir
| Package with moist air model that decouples pressure and temperature |

MoistAirUnsaturated
| Package with moist air model that decouples pressure and temperature and that has no liquid water |

SimpleAir
| Package with dry air model that decouples pressure and temperature |

Automatically generated Thu Dec 8 16:35:28 2011.