MrWidgeon wrote:Briefly Roy, where I'm from and to the people I hang around a turbo is an exhaust gas driven device to increase the amount of air supplied to a piston engine to increase horsepower.
Think turbo-charging in a sports car.
A turbine can be part of the that device (it's the actual compressor in a turbo) or in this instance as a gas turbine engine which takes in ambient air, compresses it, mixes it with fuel and ejects the hot efflux gas thus generating thrust.
In other words a jet engine, in this particular case, one that's hooked to a propellor via an extension of the turbine shaft to a gearbox.
The separation comes from the fact that a lot of large piston engines have gear driven superchargers and in the common vernacular turbochargers and superchargers were getting mixed up.
To keep their identities straight the term Turbine was applied to the turbo-prop engine (there it is again).
I think it was easier to say too - Turbo-prop Goose vs Turbine Goose. (All R-985 piston Gooses had a gear driven supercharger, so Turbo Goose would be a bit of a misnomer)
Probably more a matter of semantics than anything else.
(Here in the States an engine is something powered by internal combustion - a motor is powered by electricity)
But that's how I learned it.
Actually, the "turbine" part of a turbocharger is the "other" end in relation to the compressor. They look similar, but the turbine "wheel" is the "hot" side that is actually turned by the flow of the exhaust gases through the turbocharger housing while the relatively cold centrifugal "compressor" side is spun by the shaft connecting it to the turbine wheel. See image below. The centrifugal compressor is on the left and the turbine wheel is on the right.

In essence however, Bill is right; the primary difference is that a turbocharger is just an "auxiliary" component to a "reciprocating" piston engine whereas in terms of a "turbine" engine, it is the core or heart of the whole engine - which also happens to turn or rotate in a single continuous and therefore much smoother motion.
Also, the common confusion between the terms "turbocharger" and "supercharger" is due to the fact that superchargers were originally called "turbosuperchargers" * but the fundamental difference in terms of modern definitions is that the compressor in a supercharger is directly driven by the engine by means of a driveshaft, belt, or gear drive and there is no turbine wheel in it at all whereas a turbocharger is indirectly driven by means of the flow of hot exhaust gases. The turbine wheel within the turbocharger housing is "indirectly" driven by the flow of exhaust gases, but the compressor section is "directly" driven by the shaft connecting it to the turbine wheel. Sorry if I made that "clear as mud!"
*As a result of which Lycoming uses "
TIO" for a
Turbocharged Injected Opposed flat engine but TCM/Continental uses "
TSIO" for the same type of engine - a
TurboSupercharged Injected Opposed configuration.
For a supercharged engine like the old 340 hp 480 cubic inch ones used on McKinnon Super Widgeons, Aero Commanders, etc, Lycoming used the designation
GSO or
IGSO for Geared Supercharged Opposed or Injected Geared Supercharged Opposed configurations.
Radial engines, even as small as the P&W R-985 that is used on the "A" model Goose (among hundreds of others!) are usually
supercharged; the compressor is shaft driven directly off of the back of the crankshaft. But there are always exceptions; later versions of the huge Wright R-3350 "Turbo Compound" used
Power Recovery Turbines or PRT's that were essentially exhaust-driven
turbochargers except that instead of turning air compressors to increase the intake "upper deck" pressure (the manifold pressure upstream of the throttle plate) the exhaust turbines were actually coupled to shafts that connected to something like a hydromatic or automatic transmission on a car - a fluid coupling to the back of the main engine crankshaft that helped to turn it. On the Wright R-3350 "Turbo Compound" engine there were 18 cylinders and each group of 6 cylinders fed into a separate PRT (a total of 3 of them) which effectively negated all of the internal friction of the engine and helped it "recover" about 600 hp - for a total of up to about 3,800 bhp out of 3,350 cubic inches. Not too shabby - and they made it comparable to the much larger P&W R-4360 in terms of power.
Furthermore, the distinction between "Turbocharged" and "Turbine" aircraft engines was somewhat formalized in the late 1970's after there were numerous crashes as a result of mis-fueling accidents when ignorant line boys put "Jet" fuel into piston-engined aircraft marked with "Turbo" placards. GAMA, the General Aviation Manufacturers Association, published new standards and color codes for aircraft fuel, fuel servicing placards, and nomenclature - as a result of which all "Turbo" placards had to be removed from piston aircraft and "turbo" was reserved for reference to turbocharged piston engines while "turbine" referred to "jet" engines such as turboprops, turboshafts, turbofans, and turbojets. Once again, clear as mud, right?
In any case, that is why Antilles uses "Super Goose" for its new G-21G aircraft instead of the sobriquet "Turbo Goose" that was originally used by McKinnon for essentially the same aircraft.