The Pneumatics Library, or PL, contains the most important pneumatic components, in order to model pneumatic circuits. Coupling elements exist to connect pneumatic components with blocks of the blocks library and elements of the Modelica.Mechanics library.

This library supports the following types of models:


Modeling of 1-dimensional rotational and translation pneumatic systems.


The behaviour of air is modeled as an ideal gas.Real gas formulation is also available as a property.


As a state variable the gas pressure and the temperature in a lumped volume is used.


Temperature changes during compression and expansion can be taken into account or neglected based on the property (Environment) selection.


Each component of the main library has a lumped volume connected at each port. These components can therefore be connected in any sequence.

Modeling and simulation

Many simulation tools are essentially user-interfaces for setting the parameters of fixed simulation models. This means that the actual equations that describe the model are impossible, or difficult, to modify by users. This Modelon modelica library offers a different approach and provides much more flexibility. In combination with a simulation tool this Modelon library is a complete modeling and simulation tool. This is important to understand, since it implies that the working procedure is slightly different and contains some additional steps:

  • Build models that describe the phenomena of interest,
  • Tune the model parameters,
  • Use the models to set up an experiment that exposes the phenomena of interest,
  • Simulate the experiment,
  • Analyze the results

This Modelon library contains a large set of pre-defined models and templates that makes most modeling tasks straightforward. For many standard tasks it is possible to use the library in the same way as a pure simulation tool, i.e. it is sufficient to choose the right model, define all parameters and start the simulation.

Flexibility with prudence

It is possible for users to modify and extend most of the models in the library, and also to complement the library with custom models. It is also possible to mix with model components from other libraries. This is one of the major benefits of describing models using a high-level modeling language like Modelica. Customization of models and components can be done either from the graphical user interface and diagram view, or, for advanced users, by typing Modelica source code. There is also great flexibility in setting up experiments and analyzing results. The flexibility implies great freedom for users to define models and experiments, but may also require more attention to details and understanding.

Modelon libraries

All Modelon libraries are compatible and can be combined to solve specific engineering design tasks.

The Pneumatics library is specifically designed to model the transient and steady-state behaviour of pneumatic systems with maximum pressures less than 2 MPa. It is not recommended to use this library to model hydraulic systems by changing the medium properties. For these kind of systems it is recommended to use Hydraulics Library, a library of oil hydraulic components in Modelica.