I'd really like to hear Oggers explain how ignition timing, or valve timing, or mixtures, or flame fronts, or pumping losses, or any other of his false arguments explain why a high compression turbine engine is more efficient than a low compression turbine.
gents, are you talking turbines or pistons ? valve timing in a turbine ? when it comes to turbine engines we also discuss pressure ratio, not compression. maybe its just a misunderstanding since different things are mixed up.
the original question is well answered but of course a little bit like asking why a piston engine needs pistons . also the ram-jet explanation directs a wrong way since a ram jet is not a turbine engine. the job of a turbine disc is ( beyond driving the propeller via a gearbox at a turboprop) to drive the compressors , and when there are no compressors before the combustion chamber , for what does the turbine disc spin ?
maybe the thread beginner meant a
jet engine, since the question for what a compressor in a
turbine engine is self answering.