So did Fokker, but they were less satisfied. Do you have any drawings about how this radiator worked? I find this quite interesting.
See below Fokkers designs, old and improved one:
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Do-335 ILO the Me-210? A Proposal.
- Thread starter davebender
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So did Fokker, but they were less satisfied. Do you have any drawings about how this radiator worked? I find this quite interesting.
See below Fokkers designs, old and improved one:
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davebender
1st Lieutenant
I agree if we are talking about late 1944.
However I am talking about early 1942. A version of the Do-335 powered by reliable and readily availble DB605A engines could theoretically have entered production during the Spring of 1942 ILO the Me-210. There is no way to get a jet fighter in service that quickly.
beaupower32
Tech Sergeant
Looking at the rear radiator scoop on the Do-335, it looks very simular to the Mustangs scoop (more the H model than the D) and I think it would most likely work close to the same. Its a very effecent scoop and probably provided the cooling the rear engine needed. Also here are some line drawings with the 30mm cannons midway in the wings.
Shortround6
Major General
At the time of WW II the axial compressor was not well understood. There was a lot of theory but in practice most of the Axial compressors were hard pressed to get much above a 4 to 1 compression ratio which was achievable by a single stage centrifugal compressor.
at the end of WW II and even into Korea the production axial compressor engines could not demonstrate a clear advantage over the centrifugal compressor engines. One or another might be better but a third might well be inferior. Same could be said about some of the centrifugal compressor engines.
As has been said the centrifugal compressor engines traded frontal area for less expense and in general lighter weight for the same thrust.
From the time of the Korean war on the axial compressors kept improving their compression ratio and so were able to soon demonstrate much improved power to weight ratios and much improved fuel economy that no single or even 2 stage centrifugal compressor could match.
The fact that the axial compressor became the dominate type within 10 years of the end of the war does not mean that the axial compressor was necessarily the right choice during the war.
at the end of WW II and even into Korea the production axial compressor engines could not demonstrate a clear advantage over the centrifugal compressor engines. One or another might be better but a third might well be inferior. Same could be said about some of the centrifugal compressor engines.
As has been said the centrifugal compressor engines traded frontal area for less expense and in general lighter weight for the same thrust.
From the time of the Korean war on the axial compressors kept improving their compression ratio and so were able to soon demonstrate much improved power to weight ratios and much improved fuel economy that no single or even 2 stage centrifugal compressor could match.
The fact that the axial compressor became the dominate type within 10 years of the end of the war does not mean that the axial compressor was necessarily the right choice during the war.
No it didn't, the rear engine suffered overheating problems.
Very nice picture BeauPower, thanks for that 
Hi Marcel,
From just looking at the illustration it seems that the Fokker used an aircooled engine, where'as the Do-335 used two liquid cooled engines. The tunnel intake only really works well with liquid cooled engines, where you have the radiator form a barrier between the air intake and outtake tunnel. The Do-335 featured a veyr large rear radiator with no less than 3 rear outtakes. The design was similar to that of the P-51.
Marcel said:
Hi Marcel,
From just looking at the illustration it seems that the Fokker used an aircooled engine, where'as the Do-335 used two liquid cooled engines. The tunnel intake only really works well with liquid cooled engines, where you have the radiator form a barrier between the air intake and outtake tunnel. The Do-335 featured a veyr large rear radiator with no less than 3 rear outtakes. The design was similar to that of the P-51.
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beaupower32
Tech Sergeant
How so?
Incorrect, that was an early prototype issue solved rather early in development. The A-0 A-1 had zero issues overheating.
It didn't..
beaupower32
Tech Sergeant
I was hoping he can produce some facts towards it. I read that they changed some cooling things, but it was more towards cooling the oil than anything.
red admiral
Senior Airman
- 479
- Mar 24, 2005
It's worth noting that when installed, the drag from the Me 262 engine nacelles was greater than for the Meteor nacelles despite being a lot smaller diameter.
78% is not "excellent" performance. In fact, the real efficiency was some way below that around 72-76% for likely engine speeds. When you consider that Whittle's "less efficient" centrifugal compressor was 79% efficient. Then there are the allied axial jets like the Metrovick F2 running around 86% efficiency.
I'm the troll? When you carry on posting ridiculously pro-german claims with no evidence to back them up despite being repeatedly proven wrong?
Main problem was turbulence caused by the rear radiator outlets in front of the rear propeller. When the doors were open, it caused the aircraft to porpoise. The problem wasn't there when the doors were closed, but then the radiator couldn't get rid of as much heat, leading to the engine overheating if high power was maintained.
"One of the problems that had manifested itself as test-flying progressed was that it was found that the automatic opening of the rearoil cooler flaps caused an uncontrolled spontaneous flick which was transmitted through the lateral axis, causing the aircraft to porpoise. In order to establish the reason for this, and surmount any overheating problems with the rear engine, several tests were undertaken with the V6 fuselage "
In spite of its remarkable performance, the Do 335 failed to be seen in any numbers in Luftwaffe service. There were three main reasons for this. Firstly, the bombing of the Dornier factories which caused severe disruption to production plans; secondly the problem of the weakness of the undercarriage which was never satisfactorily solved; and thirdly, difficulties with stability. An insight into this last problem was given in a preliminary interrogation by USAAF staff of the respected Luftwaffe fighter ace, Generalleutnant Adolf Galland, on 14 May 1945:
"Galland had flown the Do 335, but although he found it a good aircraft, he believed it would require considerable improvement in design before it could be accepted as operational. As a twin engined fighter it lacked the stability required, and usually found, in such aircraft. He attributed this lack of stability to the distance between the two engines. In comparison to a single-engined fighter he stated that it handled 'too heavy'."
Dornier Do 335: The Luftwaffe's Fastest Piston-Engine Fighter by J. Richard Smith , Eddie J. Creek and Gerhard Roletschek
Italy also designed a push-pull aircraft, the Jona J.10 from the mid 1930s. It was supposed to be a heavy fighter as well. Fiat A.80 radial and Isotta-Fraschini Asso XI inline. Speed was 600km/h at 4500m.
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A-12, WNr 240112, crashed because of an engine fire due to overheating. Sure the overheating problems was cured.
Werner Lerche mentions checking the rear engine coolant temperature but not the front engine coolant temperature. Only one reason to check the rear engine temperature, because it wasn't cooled as good as the front engine.
I would very much like to see you back that up, esp. considering how much faster the Me262 is compared to the Meteor (And you can forget about the wing area fairytale, that has been thuroughly busted)
All available evidence points towards the Jumo 004B being a lot less draggy when installed than the RR Derwent ever was.
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I suggest moving the jet discussion into an appropriate thread.
I agree with the original poster, I have often speculated about a similar design. Using two precious DB603s for a single fighter always seemed like a serious waste considering how great even a basic conversion of the Fw 190 would've been. Two DB605s seem more reasonable.
But then, simply producing the Bf 109Z would bring you almost there with minimal effort compared to the complex pull/push design.
I agree with the original poster, I have often speculated about a similar design. Using two precious DB603s for a single fighter always seemed like a serious waste considering how great even a basic conversion of the Fw 190 would've been. Two DB605s seem more reasonable.
But then, simply producing the Bf 109Z would bring you almost there with minimal effort compared to the complex pull/push design.
red admiral
Senior Airman
- 479
- Mar 24, 2005
http://www.wwiiaircraftperformance.org/me262/RAE-german-jets.pdf
Page 4, Second Table
12lbf for the Meteor, 15lbf for the Me 262
Aerodynamically, the mid wing installation is less draggy. The problem comes in fitting a relatively long axial jet into a thin wing, which is why on the Me 262 and the Metrovick-Meteor, the axials were in underslung pods. Move to a thicker wing like the Canberra and you can bend the main spar around the compressor, but there isn't really space in a smaller wing.
I'm not sure what wing area fairytale you're on about, but the data above definitely shows the larger wing on the Meteor as being the major cause of drag compared to the Me 262. That's until you get up to around M0.80+ when wave drag from the short nacelles becomes more important - later solved a great extent by longer nacelles.
Which evidence?
Aah www.wwiiaircraftperformance.com. Good site for info on Allied, bad site for info on German aircraft. The British didn't even manage to squeeze full power out of that Me262 only achieving a top speed of 830 km/h. The average top speed with average performing engines was proven to be 870 km/h with 125 seperate a/c tested. And the British even had some reach 911 km/h in level flight during testing at Farnburough.
In short, the Meteor didn't even come close. And excuse about the wing area was just that, an excuse. The drag added in level flight was far below what would have been the case if it truly was the wing area which caused the difference in speed alone. Larger nacelles of the Derwent engine quite simply caused a lot more drag than the narrower ones of the Jumo 004. Simple concept of area rule.
In short, the Meteor didn't even come close. And excuse about the wing area was just that, an excuse. The drag added in level flight was far below what would have been the case if it truly was the wing area which caused the difference in speed alone. Larger nacelles of the Derwent engine quite simply caused a lot more drag than the narrower ones of the Jumo 004. Simple concept of area rule.
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I am not suprised it was a heavy handler. That's a lot of weight in relatively small space. I was thinking it would need boosted or hydraulicly actuated controls as apposed to standard cable runs.
Also thinking that as an interceptor, it could probably have external tankage (to get to the fight- internal once it got there) and relatively short wings. The idea would be to produce an aircraft that climbed, dived and flew extremely well but was not much of a turner. Definitely a bang and boom fighter. Rolls would be fast, especially with the hydraulics. However, stability due to the high horsepower/torque in a short fuselauge, would be a problem.
Definitely going to need some type of dive brake on this thing, otherwise, it's compressability city on every descent.
Galland must have flown an early prototype cause Do-335A was mentioned as a stellar performer by all who flew it, including test pilot Hans Werner Lerche who was the birds main test pilot. According to him the a/c was contolled with a light touch and was very maneuverable, and performance was mind blowing.
In his book 'Luftwaffe Test Pilot' Lerche describes the aircraft in detail and litterally has nothing but praise for the a/c, not a single bad word about it at all.
In his book 'Luftwaffe Test Pilot' Lerche describes the aircraft in detail and litterally has nothing but praise for the a/c, not a single bad word about it at all.
Haha, he mentions checking wether the rear engine had sustained any damage after having been attacked by looking at its oil temperature, explaining that if the rear oil or coolant system had been hit then the engine would've seized within 30 seconds. That's all he says and thats why he esp. checked the rear engine oil temperature, and the exact same would've happened to a P-51 being hit in the oil cooler or radiator. I have the book, so don't make stuff up.
