2006-12-30 04:06:30 · 3 answers · asked by mickey 2 in Cars & Transportation ➔ Aircraft
Hmm... why do some of these sound like homework questions and are we really helping anyone by answering them.
In a pure jet all of the air used by the engine passes through the compressor, the combustion chamber and then out through the turbine. The thrust is all produced by accelerating the air out the back of the engine.
In a turboprop the gas turbine provides power to a power turbine which drives a reduction gearbox which then drives the propellor. The propellor then provides most of the thrust.
2006-12-30 08:06:46 · answer #1 · answered by Chris H 6 · 2⤊ 0⤋
They are essentially the same. Each takes a mass of air and accelerates it. Newton's Third law (equal and opposite reaction) means the aircraft moves forward.
A pure jet engine takes a relatively low mass airflow and accelerates it to the local speed of sound. Additional thrust can come from the exhaust expanding against the nozzle as it exits for subsonic thrust and exhaust expanding in a convergent-divergent nozzle for supersonic thrust.
A turboprop takes a large mass airflow and accelerates it to a much less degree through the propeller.
About 10% of the total thrust on a turboprop comes from the exhaust. Engines rated in Equivalent Shaft Horsepower (ESHP) take this into account.
2006-12-30 05:43:04 · answer #2 · answered by Anonymous · 0⤊ 2⤋
Hey Mr. Pilot/Mechanic: Remind me to not fly with you, OK? Or let you work on any aircraft that I fly or am a passenger on!
While the two types of engines do share some similarities, the actual generation of thrust is substantially different, as succinctly explained by Chris H.
They are anything but "essentially the same".
2006-12-30 08:36:26 · answer #3 · answered by Bostonian In MO 7 · 1⤊ 1⤋