This information is part of the Modelica Standard Library maintained by the Modelica Association.

All the models in Modelica.Fluid compute fluid properties by using medium models defined by Modelica.Media packages. Custom fluid models can also be used, provided they extend the interfaces defined in Modelica.Media.Interfaces.

All the components in Modelica.Fluid use a replaceable medium package, called Medium: the model is written for a generic fluid, and a specific fluid model can then be specified when building a system model by redeclaring the package. This can be done in different ways:

• If several components use the same medium, it is possible to select all of them within a GUI, and set them simultaneously (as they are all named Medium).
• It is also possible to declare one or more (possibly replaceable) medium packages in the model, and then use them to set up the individual components.