wmaxt
Staff Sergeant
[quote="FLYBOYJ
They were manufactured in "matched sets." Great info wmaxt![/quote]
Thanks
wmaxt
They were manufactured in "matched sets." Great info wmaxt![/quote]
Thanks
wmaxt
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Supercharging refers very specifically to forced air/fuel induction by means of tapping power directly off the crankshaft to drive the pump
Turbocharging refers to tapping power off spent exhaust fumes to drive the pump.
Turbo-supercharging refers to using a combination of both a turbocharger and a supercharger, one feeding into the other, to derive even more compression of the air-fuel mixture.
They needed a long pipe to make the thing work.
What are "scrolls" and "snails"?
As far as I know Britain never sucessfully developed a turbo-supercharger which could be mass produced. I know Germany was never able to do so.
Your knowlege of turbocharging seems to be based upon modern automotive tech. For aircraft things are quite different. For aircraft, altitude changes must be considered. Super chargers involve gears, normally one stage of a WWII fighter two-stage supercharger is at a fixed gear ratio, and the other either has one or two gears, plus neutral. The maximum pressure (usually called boost) is limited by various considerations, but in English measurments was generally limited to 18, 21, or 25 lbs of boost. With a two speed two stage supercharger, maximum boost can be achieved at two altitudes (called critical altitudes).
The Turbo-supercharger was used on Wright Cyclones, P&W Wasps and double wasps (R-2800's), as well as the Allison (on the P-3
If the target is a deer, shooting it with anything bigger than a 30/06 is pure over-kill and buys you practically nothing.
The late P-38J and the P-38L were fine up high.
Most failed quality checks or self destructed during testing.
"Boost" (which is actually manifold pressure)
The inner parts of a Turbo and a mechanical supercharger are NOT interchangeable, turbo's run much to fast and also run hotter (the heat expansion is where they get their power from). P-38s ran in the low 20,000rpm range with 26,400rpm as absolute max
(the heat expansion is where they get their power from)
schwarzpanzer said:"Boost" (which is actually manifold pressure)
Manifold Absolute Pressure is boost + N/A effects to me (RAM-air, reversion etc)
schwarzpanzer said:Yes but it could be changed a lot quicker than the Derwent and could use crappy metals (could the Derwent?)
schwarzpanzer said:They needed a long pipe to make the thing {turbo-charger} work.
Yes, but that's bad for boost, lag and aerodynamics, why bother?
schwarzpanzer said:As far as I know Britain never sucessfully developed a turbo-supercharger which could be mass produced. I know Germany was never able to do so.
Pretty sure both did (@ least 1 FW190)
schwarzpanzer said:Your knowlege of turbocharging seems to be based upon modern automotive tech. For aircraft things are quite different. For aircraft, altitude changes must be considered. Super chargers involve gears, normally one stage of a WWII fighter two-stage supercharger is at a fixed gear ratio, and the other either has one or two gears, plus neutral. The maximum pressure (usually called boost) is limited by various considerations, but in English measurments was generally limited to 18, 21, or 25 lbs of boost. With a two speed two stage supercharger, maximum boost can be achieved at two altitudes (called critical altitudes).
Yes it is! I admit my knowledge is limited for WW2-era, I know a Swiss (or Swede?) developed it @ the turn of the Century, then Garrett of USA mass-produced it.
However I know the did some WW2 planes superchargers were dual stage.
schwarzpanzer said:Did some use electromagnetic clutches to change gear then?
schwarzpanzer said:I know at least 1 Merlin (prototype) had 1 big 1 little supercharger.
schwarzpanzer said:The common UK measurement then was bar (14.7 lbs)
And lbs was just about always written as psi.
schwarzpanzer said:The Turbo-supercharger was used on Wright Cyclones, P&W Wasps and double wasps (R-2800's), as well as the Allison (on the P-38)
No, I mean a Turbo-compounder, a turbo's exhaust scroll, feeding power directly onto the crankshaft. Only used on the B29 and an Ailiner based on it IIRC?
schwarzpanzer said:A point is though 6x .50 will probably work out better than 1 20mm!
1 to 1, I'd still have the 20mm, 800rpm is enough for me.
schwarzpanzer said:Most {Jumo jet engines}failed quality checks or self destructed during testing.
Good point, what % roughly?
Lunatic said:schwarzpanzer said:No, I mean a Turbo-compounder, a turbo's exhaust scroll, feeding power directly onto the crankshaft. Only used on the B29 and an Ailiner based on it IIRC?
I don't believe anything like this was used on the B-29.
Lunatic
Lunatic said:Hmmm.... it was not that bad for aerodynamics as the pipe is rather narrow and was not protruding.
Lunatic said:is not such an issue for aircraft, as they don't generally need quick throttle response
Lunatic said:the R-2800 on the F4U Corsair incorporated a huge two stage supercharger.
Lunatic said:I'm not sure of the mechanics, but most involved a barometric switch which would automatically switch gears at a given altitude along with a manual override.
Lunatic said:If you look at RAE and other British test documents, boost is always refered to in lbs.
Lunatic said:I don't believe anything like this was used on the B-29.
FLYBOYJ said:The B-29 used an R3350-23 with a turbo supercharger.
DerAdlerIstGelandet said:schwarzpanzer said:Yes but it could be changed a lot quicker than the Derwent and could use crappy metals (could the Derwent?)
And the fact that they had to use crappy metals is why the engine was not that successful. It was not a bad design but Germany lacked the raw materials to make it effective.
schwarzpanzer said:I heard that the P47 was so fat because of the piping?
I heard it even went round the cockpit?!
Even the version of the Jumo which didn't use "crappy metals" (the A version I believe???) still had a very short operational lifespan and high failure rate.
The technology was just too new and the German mass production processes were not up to the precision needed to build them.
The correct term is "ducting." Piping is found in houses and boats!schwarzpanzer said:I heard that the P47 was so fat because of the piping?
I heard it even went round the cockpit?!
FLYBOYJ said:The B-29 used an R3350-23 with a turbo supercharger.
The B-29 or the B-50 never used the turbo compound as far as I know. I believe it was introduced after the war and the Connie and DC-7 were amoung the first aircraft to utilize it.schwarzpanzer said:Can you check if any used the Wright R-3350 Turbo Cyclone?
- That had a Turbo-compounder.
The correct term is "ducting." Piping is found in houses and boats!
The B-29 or the B-50 never used the turbo compound as far as I know. I believe it was introduced after the war and the Connie and DC-7 were amoung the first aircraft to utilize it.
schwarzpanzer said:The correct term is "ducting." Piping is found in houses and boats!
Aaah!I was gonna say plumbing, that would've been correct! damn.
wmaxt said:Actualy any supercharging above 6 lbs needs to be cooled in some manor by 12lbs temps of over 400deg are common.
I've been around a while and never heard the term "Super Turbocharging" I've only known of Supercharging (mechanical) Turbocharging (exaust driven) and Turbo-Supercharging (Turbo into mechanical). Maybe Flyboy can help with this one?
wmaxt said:The Connie was designated a C-69 in WWII and flew operationaly in late '44 and in '45. I don't know if it ever saw enemy action though.
wmaxt