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: