simulation software for thermodynamic models, part 2
The software described in Part 1 of this paper is expanded to include the IRS (fluid inertia) and AC (area change) elements, which allow the modeling of fluid inertia and kinetic energy. They also permit the accounting of both stagnation and local actual thermodynamic properties. Kinetic energy, although not a necessary part of most simple models of thermodynamic systems, is vital when wave-delay or other very small-time behavior is of interest. An example of a shock tube containing a refrigerant is used as a demonstration, allowing comparison to a solution of virtually the same model carried out by difficult and laborious direct writing of the associated system equations given in the author's book. The model includes 41 IRS elements, 41 CS elements and two AC elements. Two further examples of the use of the software are also given that do not involve the IRS or AC elements: a refrigeration system and a piston-cylinder compressor. The conclusions and recommendations apply to both parts of the paper.
software thermodynamics thermodynamic properties bond graphs convection bond graphs