Do-335 ILO the Me-210? A Proposal.

[davebender]

Historical Timeline.
1923 Do J (Wal) flying boat.
Two engines mounted back to back. One pushed. The other engine pulled. This was a very successful aircraft. Consequently the tandem engine arrangement was used on other Dornier aircraft during the 1920s and 1930s such as the Do-26 flying boat.

3 August 1937.
Dornier files patent number 728044 for a tandem engine fighter aircraft.

1937 to 1941. Goppingen Go 9 Research Aircraft.
Dornier experiments with building a twin engine fighter aircraft that uses a tandem engine arrangement. Despite the lack of Luftwaffe interest the experiments were successful. This aircraft introduced tricycle landing gear and a bubble canopy that provided exceptional visibility.

Early 1940. P.59 Fighter Aircraft.
Success with the small Go 9 research aircraft led Dornier to precede with the tandem engine P.59 fighter aircraft. This project was cancelled to free resources for other projects.

May 1942. P.231 Light Bomber.
Essentially an updated version of the P.59 fighter aircraft design.

Autumn 1942. Do-335 Multi-Role Fighter.
The P.231 light bomber design is modified for the new role.

October 1943. Do-335 prototype first flight. DB603A engines.
Speed, acceleration, turning circle and general handling were considered good.

March 1944. An allied bombing raid destroys the main Do-335 production facility at Manzel. Production was shifted to Oberpfallenhofen (formerly used to produce the He-219 night fighter). This delays production for several months, by which time aviation gasoline is in extremely short supply.

May 1944. Do-335 program given top priority.
Essentially too late to matter. The destruction of German aviation gasoline hydrogenation plants was forcing a shift to jet engines.

May 1944. 10 Do-335A0 aircraft delivered for testing.

January 1945. Do-335 enters low rate production.
11 single seat fighters and 2 twin seat trainers completed by April 1945 when the factory was overran by enemy ground forces.



Alternate Timeline.
1938. RLM funds heavy fighter to eventually succeed the Me-110.
Messserschmitt enters the Me-210.
Arado enters the Ar-240.
Dornier enters a tandem engine fighter similar to the historical P.59.

1940. RLM heavy fighter flight competition.
This decides who gets the contract. All entries are powered by DB601 engines to ensure a level playing field.
Ar-240. Rejected for overall poor handling.
Me-210. Rejected for overall poor handling. "All the least desirable attributes an airplane could possess".
Dornier P.59. Well liked overall. A few minor problems like weak landing gear are easy to correct.

The Dornier P.59 is awarded the contract as the new Luftwaffe heavy fighter. It is re-designated Do-335.

Spring 1942. The Do-335 enters production ILO the Me-210.
Do-335 Long Range Day Fighter.
2 x 1,475 hp DB605 engines. Because of smaller engines the aircraft is overall a bit lighter and more compact.
450 mph max speed. Newer versions of the DB605 will push this to 475 mph.
Climb in excess of 4,000 ft/min
Acceleration and dive are superb. Roll is also good as both engines are on the centerline.
This aircraft is designed to be fast. The controls work just fine at 450 mph.
Combat radius (with drop tanks) of about 700 miles.
Without the drop tanks you can carry typical under wing ordnance..
3 x 3cm Mk108 cannon. 1 in the prop shaft. 1 in each wing root.
When used in the ground attack role the more powerful but slower firing 3cm Mk103 cannon may be carried.

1943. Do-435 night fighter.
This is essentially an adapted version of the twin seat Do-335 trainer. It will specialize in killing those pesky RAF Mosquito path finder aircraft. It has the speed to catch anything and enough endurance to maintain the chase across Germany.

 

[Soren]

The Do-335 was a great aircraft, but to be honest the Germans would've benefitted a lot more from a redirection of resources towards a quicker adoptation of jet engines. The Jumo 004, while clearly ahead of any jet engine the Allies had in service, could've benefitted greatly from just a single extra year of research. The Jumo 004C which was ready in early 45 would increased not only the performance of the engine by over 10% but even more importantly astly improved its' fuel efficiency, allowing an equipped 262 to reach Britain and back. Such a thing would've doomed the Allied bomber offensive completely.

 

[Burmese Bandit]

And, as I and others have pointed out time and again, dave, you CANNOT fire any type of 30 mm cannon synchronized through the prop!

Although as all on this forum know, I am a great fan of the 335 and the tandem concept.

 

[timshatz]

Notwithstanding Burmese point on the 30mm (if it can't be done, it can't be done, maybe one through the prop and a couple of 20mm through the prop), I agree with him on the concept. It seems the tandem, heavy fighter concept was not suficienty explored.

It seems that inline engines would allow the power and streamlining needed to make the concept effective. Put the fuel in the wings, armaments package underneath and slightly behind the pilot (with exception of the hub cannon) at it might work. The twin engined concept with a paddle prop would give you an excellent concept for a heavy interceptor. IMHO.

 

[Soren]

The 30mm Mk103's weren't going to be firing through the propeller arc, one was through the hub the two other were mounted midwing. I just think dave accidently wrote wing root.

 

[timshatz]

I did a quick look on Wiki and compared the P38 to the Do335. The Arrow came in about a ton lighter at max weight with the same horsepower. Add in less drag associated and it makes it a winner.

Anybody have any idea how the Arrow handled? Probably dumped altitude in a heartbeat. Have to wonder if it could catch the P47 in a dive.

 

[red admiral]

The Do-335 was a great aircraft, but to be honest the Germans would've benefitted a lot more from a redirection of resources towards a quicker adoptation of jet engines. The Jumo 004, while clearly ahead of any jet engine the Allies had in service, could've benefitted greatly from just a single extra year of research. The Jumo 004C which was ready in early 45 would increased not only the performance of the engine by over 10% but even more importantly astly improved its' fuel efficiency, allowing an equipped 262 to reach Britain and back. Such a thing would've doomed the Allied bomber offensive completely.

Why do you persist in posting this nonsense?

The Jumo 004 is clearly ahead of ever jet engine the allies had in service by being inferior in every way?

Please tell me how the C-version results in better fuel consumption by increasing turbine temperature? This actually has completely the opposite effect, and with the limited reheat on the -D massively increase fuel consumption.

You're living in a dream world.

 

[Soren]

Why do you persist in posting this nonsense?

The Jumo 004 is clearly ahead of ever jet engine the allies had in service by being inferior in every way?

Please tell me how the C-version results in better fuel consumption by increasing turbine temperature? This actually has completely the opposite effect, and with the limited reheat on the -D massively increase fuel consumption.

You're living in a dream world.

Aw, did I hurt your feelers?

I'm afraid you're the one who's posting nonsense.

The Jumo 004 was to undergo various improvements during its service life, some of which resulted in new improved versions of the series. One of these was the Jumo 004D which featured a two-stage fuel injector and a new throttle control, both of which improved fuel efficiency over the Jumo 004B engine. Maximum turbine rpm's was increased to 10,000 rpm and thereby a new thrust output of 10.3 kN's was achieved. This engine was ready to enter full scale production shortly before the war ended. Had it been available in the middle of 1944 it is likely that the war in the skies over western europe would've turned out quite differently. Esp. as this engine had a much reduced chance of experiencing flameouts and featured an improved engine life.

 

[red admiral]

So you've quoted some text from somewhere? That's hardly proof of your ridiculous claims, especially when the source is wrong.

 

[Soren]

It's better than what you've achieved so far...

Facts are these:

The Jumo 004D featured a new two stage fuel injector and throttle control, both of which improved upon the fuel efficiency while the new throttle control prevented flameouts.

You can choose to accept this or not, doesn't matter the slightest to me.

 

[red admiral]

The Jumo 004D featured a new two stage fuel injector and throttle control, both of which improved upon the fuel efficiency while the new throttle control prevented flameouts.

This does not equate to "vastly improved fuel efficiency giving Me 262s the ability to fly to England and back". A small change (because that's all there is to be had) in combustion efficiency doesn't suddenly make it a super engine.

The Jumo 004, while clearly ahead of any jet engine the Allies had in service

Clearly ahead in what way? None?

 

[Milosh]

I would like to see more specific details on these 'new and improved' Jumo 004 engines.

 

[Matt308]

Take it easy guys.

 

[Soren]

Don't worry, I'm not talking to the troll anymore.

 

[Matt308]

Soren, you have the right to remain silent. But you do not have the ability.

 

[Soren]

I'm human, I don't like being attacked, that's normal enough I'd say. There was no reason for red admiral to step in in such a childish manner. Anyway I'm not going to discuss it any further cause we're ruining Dave's thread.

I personally like the idea of the Do-335 being used as a nightfighter bomber destroyer, esp. if it could've been achieved as early as the beginning of 1944. I am however also of the opinion that the resources would've been even better spent on the further development of the Jumo 004 engine and quicker service entrance of the Me262.

 

[Marcel]

I have a book about the Fokker D.XXIII, an aircraft with the same tandem configuration like the Do-335, only 6 years earlier. Biggest problem was the cooling of the rear engine, which Fokker redesigned frequently, but never cured totally until the project was stopped in 1940. I was wondering if the Do-335 had these same problems, and if not, how Dornier solved this difficult problem.

 

[Soren]

Some nice pictures of the bird:

 

[Soren]

I have a book about the Fokker D.XXIII, an aircraft with the same tandem configuration like the Do-335, only 6 years earlier. Biggest problem was the cooling of the rear engine, which Fokker redesigned frequently, but never cured totally until the project was stopped in 1940. I was wondering if the Do-335 had these same problems, and if not, how Dornier solved this difficult problem.

Dornier solved this with a nice tunnel radiator for the rear engine. Worked beautifully.

 

[beaupower32]

Clearly ahead in what way? None?

You have to figure that the jet engines the USAAF and RAF had were centrifugal type and the Jumo 004 was a Axial flow. The big hit with centrifugal was that Centrifugal flow engines compress the air by accelerating air outward perpendicular to the longitudinal axis of the machine. Centrifugal compressor engines are divided into Single-Stage and Two-Stage compressor. The amount of thrust is limited because the maximum compression ratio. So their main advantages are 1. Light Weight 2. Simplicity 3. Low cost.

The Germans developed the Jumo 004 with as a Axial Flow engine.They utalized a new type of compressor which allowed a continuous, straight flow of air through the engine. The axial-flow compressor not only had excellent performance, about 78% efficient in "real world" conditions, but it also had a smaller cross-section, important for a high-speed aircraft design.

The centrifugal flow compressor employs an impeller to accelerate the air and a diffuser to produce the required pressure rise. Flow exit's a centrifugal compressor radially (at 90° to the flight direction) and it must therefore be redirected back towards the combustion chamber, resulting in a drop in efficiency. The axial flow compressor employs alternate rows of rotating (rotor) blades, to accelerate the air, and stationary (stator) vanes ,to diffuse the air, until the required pressure rise is obtained.

The pressure rise that may be obtained in a single stage of an axial compressor is far less than the pressure rise achievable in a single centrifugal stage. This means that for the same pressure rise, an axial compressor needs many stages, but a centrifugal compressor may need only one or two.

An engine design using a centrifugal compressor will generally have a larger frontal area than one using a axial compressor. This is partly a consequence of the design of a centrifugal impeller, and partly a result of the need for the diffuser to redirect the flow back towards the combustion chamber. As the axial compressor needs more stages than a centrifugal compressor for the equivalent pressure rise, an engine designed with an axial compressor will be longer and thinner than one designed using a centrifugal compressor. This, plus the ability to increase the overall pressure ratio in an axial compressor by the addition of extra stages, has led to the use of axial compressors in most engine designs, however, the centrifugal compressor is still favored for smaller engines where it's simplicity, ruggedness and ease of manufacture outweigh any other disadvantages.