# ReleaseNotes.Version_2_2

## Information

Version 2.2 is backward compatible to version 2.1.

The following new libraries have been added:

Modelica.Media | Property models of liquids and gases, especially 1241 detailed gas models, moist air, high precision water model (according to IAPWS/IF97 standard), incompressible media defined by tables (cp(T), rho(t), eta(T), etc. are defined by tables). The user can conveniently define mixtures of gases between the 1241 gas models. The models are designed to work well in dynamic simulations. They are based on a new standard interface for media with single and multiple substances and one or multiple phases with the following features: The independent variables of a medium model do not influence the definition of a fluid connector port or how the balance equations have to be implemented. Used independent variables: "p,T", "p,T,X", "p,h", "d,T". Optional variables, e.g., dynamic viscosity, are only computed if needed. The medium models are implemented with regards to efficient dynamic simulation.
Modelica.Thermal.FluidHeatFlow | Simple components for 1-dim., incompressible thermo-fluid flow to model coolant flows, e.g., of electrical machines. Components can be connected arbitrarily together (= ideal mixing at connection points) and fluid may reverse direction of flow.

The following changes have been performed in the Modelica.Mechanics.MultiBody library:

- Component MultiBody.World has a new parameter driveTrainMechanics3D. If set to true, 3D mechanical effects of MultiBody.Parts.Mounting1D/Rotor1D/BevelGear1D are taken into account. If set to false (= default), 3D mechanical effects in these elements are not taken into account and the frame connectors to connect to 3D parts are disabled (all connections to such a disabled connector are also disabled, due to the new feature of conditional declarations in Modelica language 2.2)
- All references to "MultiBody.xxx" have been changed to "Modelica.Mechanics.MultiBodys.xxx" in order that after copying of a component outside of the Modelica library, the references still remain valid.

Generated at 2018-08-07T07:53:32Z by OpenModelicaOpenModelica 1.13.0~dev-1195-g6d891ea