Can anyone tell me the difference between staged combustion and full flow staged combustion?
Does full flow mean there are 2 preburners (fuel- and oxidiser-rich respectively) or does it mean that all of the propellant goes through the preburner before entering the combustion chamber?
I've drawn for reference.
(that red line drawn to FR (fuel rich) on the left is meant to be a label line, not plumbing)
The far right is definitely full flow staged combustion but what are the other two?
Also, I've noticed that the SSME is almost the same as the rightmost but it has some oxidizer go straight to the combustion chamber. It is classified as staged combustion. This suggests full flow means both propellants are flowing through a preburner before getting to the combustion chamber.
But what then are the 2 diagrams on the left?