LBL logo


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


Medium models in this package use a constant mass density.

The use of a constant density avoids having pressure as a state variable in mixing volumes. Hence, fast transients introduced by a change in pressure are avoided. The drawback is that the dimensionality of the coupled nonlinear equation system is typically larger for flow networks.

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

u = h - p ⁄ ρstp,

where u is the internal energy per unit mass, h is the enthalpy per unit mass, p is the static pressure and ρstp 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 ⁄ ρstd,

because ρ = ρstd in this medium model.

Extends from Modelica.Icons.MaterialPropertiesPackage (Icon for package containing property classes).

Package Content

Buildings.Media.GasesConstantDensity.MoistAir MoistAir Package with moist air model with constant density
Buildings.Media.GasesConstantDensity.MoistAirUnsaturated MoistAirUnsaturated Package with moist air model that decouples pressure and temperature and that has no liquid water
Buildings.Media.GasesConstantDensity.SimpleAir SimpleAir Package with dry air model that decouples pressure and temperature
Buildings.Media.GasesConstantDensity.Examples Examples Collection of models that illustrate model use and test models

Automatically generated Wed Feb 29 16:54:13 2012.