specter177 wrote on Apr 10^th, 2008 at 2:52pm:


Correct.
It has to do not with how combustion takes place in the engine, but how the engine provides propulsion "where the rubber meets the road". Turboprops use a stream of fluid (hot gas) to drive a turbine, but the turbine is not what pulls the plane forward; it's the prop.

Jet engines also have turbines inside, but again, they don't provide thrust- it's the fluid being expelled that does it.

I say "fluid" because it could be air, water, or almost anything that's a fluid: there are marine engines that work on the same principle... and there are even animals, like the squid, that use jet propulsion.



http://en.wikipedia.org/wiki/Jet_engine

http://en.wikipedia.org/wiki/Turboprop


In the case of the P-51 Mustang, it's neither a turboprop nor jet, but a piston-driven prop. Completely different sort of engine.