Best Jet of WW2?

[DerAdlerIstGelandet]

Pretty neat.

[Nonskimmer]

Yeah, interesting!

[DerAdlerIstGelandet]

How far do you think until someone in WW2 would have put out a turbo fan, or how long until someone broke the sound barrier in WW2. The Germans were close with the Me-163 and could have possibly done it with the P.1011 had it flown and been produced. The US did it shortly after WW2.

Originally Posted by DerAdlerIstGelandet

How far do you think until someone in WW2 would have put out a turbo fan, or how long until someone broke the sound barrier in WW2. The Germans were close with the Me-163 and could have possibly done it with the P.1011 had it flown and been produced. The US did it shortly after WW2.

I think the turbofan required the turbojet to be fully debugged first, but it could have been done at any time. The turbofan is a little more complicated and it is not intuatively obvious that it will give performance gains (primarily in fuel economy).

As for breaking the sound barrier, it may have been done as early as sometime in 1946. But any usuable supersonic flight was still a long ways away. Flight dynamics change drastically above the speed of sound, and materials technology, even in the USA, had to progress a bit to sustain supersonic flight. Had the P.1011 been built and been capable of supersonic flight, it would have disintigrated or melted when it achieved it. But in reality, I suspect it could not have done so, it was not going to have as high a performance as the Mig-15, it didn't have the engine for it.

=S=

Lunatic

[DerAdlerIstGelandet]

I agree that a usuable turbofan was still quite a ways off but I think it could have been done in WW2

I will also agree that the P.1011 would have required better engines and the 163 was probably the closest they would have gotten to it.

But even the 163, upon forcing its way through the mach barrier, would have been torn apart. It takes titanium alloys to withstand such speeds, or at the very least, steel. Aluminum would get soft and collapse very quickly.

And remember, above mach speed, the air acts like a solid. There was no knowlege of how to control a plane flying through "butter".

=S=

Lunatic

[delcyros]

The Me-163 was (most probably) unable to break Mach 1. It has a critical Mach speed of 0.84 and above that speed it pitched strongly down. (that happened a few times during the test program and in almost all serial Me-163 B was a warning sound and flashing light installes if they come close to its critical Mach speed) Even the X-4 proved that tailles planes were not suited for high transsonic/supersonic speeds after the war. I think the Me-P.1101 could come much closer (0.94), but it remains still debatable if the airframe could sustain such stress. There were at least 3 tries beside of manned A-4´s and Sängerplanes (which cannot be taken for that serious) to build a supersonic plane:
Horten Ho XIIIb: 60 degrees swept back wing (but very thick) with He-S011 and rocket assistance. The unpowered testbed Ho-XIIIa was build and flew, it was used to get informations about the low speed handling of such a wing design.
Lippisch P-13: A little similar to Horten but it has a deltawing (still the profile was too thick, it would generate too much drag at Mach 0.7-1.3)-
DFS 346: A supersonic testbed. 45 degrees swept back wings (very thin) and all metal design. Powered by two HWK-109 B rocket engines it developed 4000 Kp thrust (almost 8.800 lbs) and the whole design was geometrically well suited for breaking the sound barrier (comparable to X-1, but with smaller fuselage diameter and swept back wings with higher aspect ratio). Estimated speed: 2270 Km/h at 20.000 m (1400 mp/h = Mach 2.2 at 65000 ft.). Only the V-1-prototype was nearly finished at Siebel by VE-day. It is interesting that the US had no intentions for that plane, so they left it for the soviets. After some delays it was completed by Siebels for the soviets and in mid 1946 it was together with german pilots and technicians brought into the soviet union, where it was flown from early 1948-1951 (it has to be refittetd for two HWK 109A-1, since there were no .-109B in the USSR, two more planes were build under the name samoljet 346 "airplane 346"). Ziese inofficially did succed in breaking the sound barrier with this plane (however, the left wing broke at 60000ft. altitude maybe in this flight, but I´m unsure).

[delcyros]

a few pictures of the DFS 346 (source: J. Dresser, M. Griehl, Die deutschen Raketenflugzeuge 1939-1945, 2nd edition (Augsburg 1999), page 89-92):
Compare also http:\\jpcolliat.free.fr/trident/trident-15.htm
or www.prototypes.com/Les intercepteurs à moteur-fusée/XV. ANNEXE : le DFS 346

[GermansRGeniuses]

Originally Posted by delcyros

DFS 346/Samoljet 346 with B-29 carrierplane

Tu-4, in reality, since the DFS is in Russian custody.

[the lancaster kicks ass]

and that's a B-17 in the pic not a B-29 isn't it??

[delcyros]

Yes, Tu-4. (a soviet build licence B-29) I named that (incorectly) B-29 in order to credit it as an US design.

[Nonskimmer]

The Tu-4 wasn't built under licence, it was copied from captured B-29's.

Originally Posted by Nonskimmer

The Tu-4 wasn't built under licence, it was copied from captured B-29's.

Damn right. In July 1944 several B-29's based in China were unable to make it all the way to their bases and landed on a Soviet base. The Russians refused to return the planes or aircrews (who were held as prisoners - though treated relatively well, until the end of the war), on the basis that the USSR was neutral w.r.t. the war against Japan.

http://archives.cnn.com/2001/US/01/2...nian.cold.war/

http://aeroweb.lucia.it/~agretch/RAFAQ/Tu-4.html

In my opinion, the USA should have demanded the immeadiate return of the Bombers and crews. Had the Soviets refused, the USA should immeadiately have cut off all Lend-Lease aid to the Soviets. Perhaps this should have been done without even making a demand. When the Soviets indicated their intentions to hold the bombers and crews, LL aid should have stopped, and then negotiations for return of the bombers should have been stalled till Germany was defeated. This would have been good for the USA, as it would have slowed Russia's progress against the Germans and made for a better post war position for the W. Allies. It also would have denied the Soviets much of their German technology captures, as the W. Allies would have occupied almost all of Germany proper.

=S=

Lunatic

[wmaxt]

Originally Posted by RG_Lunatic

Damn right. In July 1944 several B-29's based in China were unable to make it all the way to their bases and landed on a Soviet base. The Russians refused to return the planes or aircrews (who were held as prisoners - though treated relatively well, until the end of the war), on the basis that the USSR was neutral w.r.t. the war against Japan.

http://archives.cnn.com/2001/US/01/2...nian.cold.war/

http://aeroweb.lucia.it/~agretch/RAFAQ/Tu-4.html

In my opinion, the USA should have demanded the immeadiate return of the Bombers and crews. Had the Soviets refused, the USA should immeadiately have cut off all Lend-Lease aid to the Soviets. Perhaps this should have been done without even making a demand. When the Soviets indicated their intentions to hold the bombers and crews, LL aid should have stopped, and then negotiations for return of the bombers should have been stalled till Germany was defeated. This would have been good for the USA, as it would have slowed Russia's progress against the Germans and made for a better post war position for the W. Allies. It also would have denied the Soviets much of their German technology captures, as the W. Allies would have occupied almost all of Germany proper.

=S=

Lunatic

It's my understanding that to about mach 1.6 aluminum alloys are fine if the shape of the aircraft is correct. Using sweep and in early cases the area rule helped an aircraft to cross the sound barrier at least momentarily. One example was the F-86 that could in a dive exceed the speed of sound without special materials.

The trick to controlability was the use of the stabilator or flying stabilizer to allow pitch athority which is lost when a normal elevator is behind the Sonic shock wave on the stabilizer.

By Mach 2 materials like steel are required and titanium above mach 3 then it starts getting exotic with carbon-carbon etc.

Hmmm... It was my understanding that to sustain supersonic speed you needed to use superior alloys. Once over the sound barrier, heat will build up and makey duraluminum soft.

I agree, momentarily crossing the threshold would not imeadiately cause enough heat to cause a failure, but sustaining even Mach 1.1 for any length of time probably would. There's no real good way to vent the heat, the wing is not getting much airflow.

=S=

Lunatic