A thermodynamic process is reversible if the system remains in the equilibrium state throughout. That's what we are told in the book. My doubt is, though, can we judge whether a process is reversible or not by looking at the P-V diagram?
Technically, P-V diagrams should only be used for a reversible process, as irreversible processes involve inhomogeneous pressure and temperature. However, I have seen P-V diagrams for Diesel cycles and Otto cycles, which are not reversible because of the sudden explosion of fuels. I am very confused by this. What's wrong?
It appears that any path on a P-V diagram can be reversible if the process is performed very slowly. Is that true?
- Does reversibility have anything to do with the P-V diagram?
- If I do not understand the above correctly, what are some examples of irreversible cycles?