Introduction

Purpose

The Jet Propulsion Library or JPL is intended for modeling and simulation of jet engines of both commercial and military aircrafts and the model-based design of integrated aircraft systems. The comprehensive set of components in the library enables cycle performance analysis and optimization of all types of aerospace gas turbines. On-design and off-design performances can be studied as well as steady-state and transient behaviors based on a single model. This provides a fully rigorous foundation for sizing and performance computations and provides several advantages over existing domain-specific solutions due to the use of the Modelica language.

Models are designed in a way that is similar to the structure of real aircraft engine assemblies. The library is hierarchically organized and grouped into intuitive sub packages. Custom built components are also easily integrated in the models.

The library is compatible with other Modelon libraries and Modelica Standard Library (MSL).

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. Jet Propulsion 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

Jet Propulsion 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.