EagleRJ said:-Turbo-compounding- Not really supercharging at all, but using an exhaust-driven turbine that is connected to the crankshaft by a gearbox. Used to recover lost energy in the exhaust and return it to the crankshaft as additional power.
You'll find that out if you ever have to get TSIO-470's worked on...they just about have to dig out some Egyptian stone tablets and dust them off, just to get a clue.VNugget said:Also note that sometimes you'll see "supercharged" referring to either, especially in older writing.
The flip side of this is that because the supercharger is directly connected, it doesn't suffer from the lag that turbos do. On a turbo, the turbine needs to spool up, which results in a bit of lag before it begins providing boost.
If you're talking about aircraft engines, turbocharging is more common than supercharging- probably because the supercharger's drive belt is one more thing to break in an airplane (there are gear-driven designs too, but it's still more complex).
Turbo-compounding- Not really supercharging at all, but using an exhaust-driven turbine that is connected to the crankshaft by a gearbox. Used to recover lost energy in the exhaust and return it to the crankshaft as additional power.
avbug said:The turbocompound R3350 utilized a supercharger as well as power recovery turbines, which provided drive back to the engine mechanically through a fluid coupling, so yes, it really is supercharged...the compound in turbocompound is supercharging plus the PRT's.
BD King said:In line with the subject matter, if you ever fly, especially a 400 Series Cessna that still has Turbo Charged on the side or on the cowls, watch the lineman very closely when refueling.
Man those mofo's were complex weren't they? I'm suprised they didn't have 1 flight eng. for each motor. From what I understand pax in those days weren't phased at all when a shutdown occured. I also read that the exaust developed quite a bit of thrust.
avbug said:I don't recall ever hearing that the exaust put out any significant amount of thrust, though I'm sure it may impart something. If that were the case, the exhaust would probably be angled back to take advantage of the "thrust."
A Squared said:The exhaust stacks on the DC-6 point straight back, ostensibley to take advantage of exhaust thrust, according to one of my Douglas manuals. I don't have the book in front of me, but is seems like I recall they were claiming to recover several hundred horspower that way.
A Squared said:Seems like I'd heard that the "turbo system" that Cessna put on the cowls was required to be covered or removed by an Airworthiness Directive. Anyone know if this was true?