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


Medium models in this package use the gas law d/dstp = p/pstp where pstd and dstp 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 - pstp ⁄ ρstp,

where u is the internal energy per unit mass, h is the enthalpy per unit mass, pstp 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 - pstp ⁄ ρstd,

because p ⁄ ρ = pstp ⁄ ρstp in this medium model.

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

Package Content

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

Automatically generated Thu Oct 24 15:10:44 2013.