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## Main Question or Discussion Point

Hey guys (and girls?)

I'm new here, just registered, because I have a problem that my textbooks or google can't help me with:

I am making "Brayton cycle diagrams" for a study in jet engine efficiency. It's basically a Temperature - Entropy diagram for those of you who are unfamiliar with it. I know how to calculate the temperature increase with a pressure increase (basic isentropic relationships), and the entropy increase with fuel addition (delta S = q * LN( delta T)).

The problem I'm having is calculating lines of constant pressure in this diagram. Every source talks about them, but no source tells me how to calculate them. I know they are supposed to be increasing curves (the temperature difference for a pressure ratio is higher at higher entropy).

Does anyone have a clue to calculate these isobars?

Any help is greatly appreciated!

I'm new here, just registered, because I have a problem that my textbooks or google can't help me with:

I am making "Brayton cycle diagrams" for a study in jet engine efficiency. It's basically a Temperature - Entropy diagram for those of you who are unfamiliar with it. I know how to calculate the temperature increase with a pressure increase (basic isentropic relationships), and the entropy increase with fuel addition (delta S = q * LN( delta T)).

The problem I'm having is calculating lines of constant pressure in this diagram. Every source talks about them, but no source tells me how to calculate them. I know they are supposed to be increasing curves (the temperature difference for a pressure ratio is higher at higher entropy).

Does anyone have a clue to calculate these isobars?

Any help is greatly appreciated!