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As a Brit I put up my Spitfire of the latest marque in every year from 1939 to 45, now tell me which turbo US aircraft will "own" it at high altitude. The B17 was flying in 1939 it was not service ready especially for daylight raids in contested airspace it was first used by the RAF in July 1941The advantages of turbocharging vs supercharging piston aero engines are so great why did not every country use them in WW2. The US lead this field by a long way and OWNED high altitude combat in WW2. By 1939 the turbocharged B-17 was service ready so why did other countries, especially the "high-tech" Germans totally fail to get turbo'd planes working?
This is a classic case of theory, excellence and practicality being in conflict. A turbo first stage and supercharger second stage may well be the best theoretical solution but which engine and airframe will it be applied to in 1939. Whether a water cooled V or a rotary air cooled engine you need a big airframe and also in terms of logistics both a supercharger and a turbo.Compare the high altitude performance of a P-47 and an F6F - or even more appropriately the Seversky AP-4 and the XP-41 - and you'll see that two stage supercharging using a turbo for the first stage was superior to mechanically driven supercharging..
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Still I wonder what the hp loss of a 2 stage high speed blower is?
The advantages of turbocharging vs supercharging piston aero engines are so great why did not every country use them in WW2. The US lead this field by a long way and OWNED high altitude combat in WW2. By 1939 the turbocharged B-17 was service ready so why did other countries, especially the "high-tech" Germans totally fail to get turbo'd planes working?
- Efficient intercoolers needed to be designed if the advantages were to be fully exploited
No different than 2 stage mechanical units.
Even after WWII, commercial airliners continued to rely on mechanically supercharged engines.
You don't need a 2 stage system when your flying at the altitudes most Commercial aircraft were flying at the time. Most used single stage; although a couple not long before the jet age did use turbo-compounds.
- The possibility of extracting jet thrust from the exhaust was lost (if the later and not very successful VDT concept is excluded)
Oh there's thrust alright, just not as much. The Jug only lost 20hp +/- in the climb instead of a couple of hundred for those without a turbo and using 2 speed/2 stage mechanical units.