It is thus possible to display on the diagram the state values of the various points representing the system under investigation. The interactive charts have been developed with a view to replace classical paper thermodynamic charts. Indeed, whatever care is taken by editors in the choice of color sets for distinguishing the various curves shown on the classical charts, it is always difficult to read them, and interpolation may lead to significant errors. Since energy conversion technologies can be represented as an assembly of interconnected components, their system analysis can be based on a combination of a system design for the studied project, which allows one to bring to the fore its main functional elements and their interconnections, and a steady-state thermodynamic modeling of its various elements. Applied thermodynamics is indeed a relatively complex science, the physical laws being very nonlinear.
Thermodynamic fluids are either ideal gases or vapors.
The first are relatively easy to model as compared to the second because they are governed by much more complex equations. These fluids undergo various transformations, themselves also nonlinear, from the simplest like compressions or expansions, to more complex ones leading to composition changes, such as combustion or moist gas condensations. These can be adiabatic or polytropic, and are characterized by their isentropic or polytropic efficiency. Fuel can be introduced into the combustion chamber separately from the oxidizer, or premixed. The dissociation of the carbon dioxide can be taken into account.