Focke-Wulf swept-wing pusher fighter with contra-rotating propellers

[blackkite]

Hi!
Someone please show me the name of this aircraft.

 

[Jemiba]

Looks like a Dornier P.247 to me .
(see http://www.luft46.com/dornier/dop247.html )
There were several designs, that may explain the differences in the shape of the tail.

 

[blackkite]

Thanks Jens!
This drawing is from Japanese AIR WORLD magazine, special edition in February 1986, J&P NO.1 Gekko and Phantom.
Accoring to this book, this fighter was Focke Wulf design.
" 0310 025.-509" is Focke Wulf's drawing number.
Perhaps this fighter did not have a name!?

 

[Jemiba]

You're right, sorry, I got it wrong ! :-[
The Do P.247 was a low wing, the Fw a mid wing aircraft. Still yet, I knew the Fw as a mixed
propulsion fighter, but there may have been projects for piston engined types, too.
Couldn't find another designation, than those drawing numbers still yet, nevertheless.
(Drawing from Aerokurier 3/1965)

 

[blackkite]

Many thanks Jens! I have a chart for this project.
高性能 = high performance, 戦闘機 = fighter, 全天候 = all weather, 付 = install, 推進式 = pusher type, 翅 = propeller blade,
反転 = contra rotating, プロペラ = propeller, 座 = seat, 水平尾翼 = horizontal tail stabilizer, 前進角 = forward swept angle,
暫定案 = tentative plan
b is wing span? L is overall length? What is F? Wing area?　

 

[Stargazer2006]

Very interesting design. I changed the topic's name until a proper designation emerges (if ever).

 

[blackkite]

Many thanks Star as usual.
Maximum speed : 815km/h!

 

[blackkite]

Hi!
0310 025-1006
http://www.luft46.com/fw/fwp0310.html
And 0310 251-13
http://www.luft46.com/fw/fwp0310b.html

 

[blackkite]

I think this Focke Wulf pusher fighter need forced cooling fan especially at engine ground test same as attached fighter, but I can't find forced cooling fan in design drawings. :-[

 

[robunos]

Blackkite, both your aircraft, and the subject of this thread, are powered by liquid-cooled engines (Jumo 222, and BMW 803).
See my images below for the location of the radiators, cooling fan (not fitted to the 'unknown' aircraft), and the air inlets.

cheers,
Robin.

 

[Jemiba]

The pusher prop/twin boom is said by Novarra in "Die Deutsche Luftrüstung 1939 - 45" maybe to be a parallel design
to the jet fighter design VII ("Flitzer"), buthere, too, no type/project number is given.
And it said to have been the starting point for the French "Sud-Ouest SO.8000 Narval naval fighter.

 

[Stargazer2006]

And it said to have been the starting point for the French "Sud-Ouest SO.8000 Narval naval fighter.

Certainly looks it! Thanks for the info.

 

[blackkite]

Blackkite, both your aircraft, and the subject of this thread, are powered by liquid-cooled engines (Jumo 222, and BMW 803).
See my images below for the location of the radiators, cooling fan (not fitted to the 'unknown' aircraft), and the air inlets.

cheers,
Robin.

Many thanks Robin!
You did not see a forced cooling fan in unnamed fighter's drawings, too.
It's very strange design for me. Don't you think so?
Or strong propeller stream induced adequate air flow to the air intake at engine ground test?
Or connected air duct to the air intake from external temporary fan at engine ground test?

 

[blackkite]

The pusher prop/twin boom is said by Novarra in "Die Deutsche Luftrüstung 1939 - 45" maybe to be a parallel design
to the jet fighter design VII ("Flitzer"), buthere, too, no type/project number is given.
And it said to have been the starting point for the French "Sud-Ouest SO.8000 Narval naval fighter.

Many thanks for nice information Jens.

 

[Basil]

Blackkite,

you find some good information along with technical datas about these Focke Wulf projects in this book:
http://books.google.at/books?id=B7whAQAAIAAJ&hl=de&source=gbs_similarbooks

 

[blackkite]

Wow thanks! I will check this book.

 

[Jemiba]

You did not see a forced cooling fan in unnamed fighter's drawings, too.
It's very strange design for me. Don't you think so?

As Robunos already pointed out, the Focke Wulf would have been powered by a liquid cooled engine, whereas
the engine of the Shinden was air cooled, needing a much greater amount of cooling air. Just remember other
aircraft with liquid cooled engines, Bf 109, Spitfire or Mosquito. All had quite small cooling air intakes without
fans. And, as an example for a pusher prop, just have a look at the Saab 21.

 

[blackkite]

You did not see a forced cooling fan in unnamed fighter's drawings, too.
It's very strange design for me. Don't you think so?

As Robunos already pointed out, the Focke Wulf would have been powered by a liquid cooled engine, whereas
the engine of the Shinden was air cooled, needing a much greater amount of cooling air. Just remember other
aircraft with liquid cooled engines, Bf 109, Spitfire or Mosquito. All had quite small cooling air intakes without
fans. And, as an example for a pusher prop, just have a look at the Saab 21.

Hi Jens! Please take care that radiators of Bf109, Spitfire and Mosquito were located just behind the propeller, cooled by strong propeller after stream even at zero speed ground engine test. In case of SAAB J21, radiator were located at near propeller.

 

[Jemiba]

You're certainly right, that a prop in a "pull" configuration helps with cooling the radiatior of a
liquid cooled engine, so I should have restricted myself to pusher prop configurations. That's not
that easy, but after some search I would like to come up with three other aircraft in pusher configuration,
that, to my opinion, didn't had large cooling fans: Curtiss XP 55 Ascender, Bell YFM-1 Airacuda and the
Douglas XB-42 Mixmaster. For a liquid cooled engine, cooling is ensured by keeping the circulation of the coolant
running, mostly via a pump, as convection may help, but probably not enough. And I agree, that it often will
be more problematic, than for a conventional layout and AFAIK problems weren't uncommon in a pusher or
even a push/pull configuration, sometimes maybe solved by installation of a cooling fan, but I think, that it
wasn't generally designed that way from the start.
(Drawing from http://www.enginehistory.org/Propellers/Curtiss/XB-42Prop.shtml )

 

[blackkite]

Hi!
http://www.ipmsstockholm.org/magazine/2000/02/stuff_eng_detail_j21.htm

A total of 298 SAAB 21s were produced in five production batches. They served from 1946 to 1954.
Series aircraft were not without problems. Because of the propeller's placement, engine cooling proved to be inadequate, especially on the ground - a serious problem that was never really worked out.

Douglas XB-42 Mixmaster........Hmmmmmm..............

I believe that Ascender, Airacuda and Mixmaster had the same problem if they had no radiator fan.
Engine overheating is serious problem.
My small car also have a radiator fan. My car is pull type. ;D

 

[richard]

Bonjour


There was at least 3 configurations of the twin booms Focke Wulf fighter :

 

[blackkite]

Thanks richard.
Source : RED SERIES GERMAN AIR PROJECT 1935-1945 vol.1 FIGHTERS by Marek Rys STRATUS Poland 2003 ISBN 83-916327-5-X

 

[hesham]

Bonjour


There was at least 3 configurations of the twin booms Focke Wulf fighter :

Great find my dear Richard,


and what was it ?,I have three twin boom FW designs, P.0310.225,P.0310.251.13 or
P.011.001 fighters.

 

[Jemiba]

In the designs using the BMW 803, the cooling problem seems to have been adressed by placing the radiator
directly in the nose. And as an annular casing is used, I would suggest, that actually a fan should be used.
Cooling problems seem to have been quite familiar during this era, reading pilot reports, much emphasis was often
given to the handling of the cooling system and engine running on the ground and even taxying often seems to have
been limited, even for aircraft, with conventional layout.

BTW, sorry blackkite, had forgotten to answer your question from your post #4:
"F" generally means "Fläche" (area), so here wing area is meant, I think.

 

[richard]

Bonjour


There was at least 3 configurations of the twin booms Focke Wulf fighter :

Greta find my dear Richard,


and what was it ?,I have three twin boom FW designs, P.0310.225,P.0310.251.13 or
P.011.001 fighters.

Sorry , no name : only "Focke Wulf fighter with BMW 803" for the three ...

 

[blackkite]

Thanks Jens! German is very hard to read for me.

 

[theponja]

Thanks Jens! German is very hard to read for me.

Impossible!!!! You can read Japanese!!! How can be German difficult ?

 

[blackkite]

I can't read this document. ;D
Source : GEHEIMPROJEKTE DER LUFTWAFFE Jagdflugzeuge 1939-1945 Motor buch Verlag, ISBN 3-613-01631-1

 

[Jemiba]

Quite an interesting source !

"20.February 1945
For the concept of a high performance fighter with increased endurance, the design bureau of Prof. Tank
used the describedproject with a Jumo 222 E/F engine.
Two proposals are made: High performance fighter with Jumo 222 E/F and with Argus As 413, besides the engine
there are only few dimensional differences.

Propulsion:
1 Argus As 413 with 4000 hp take-off power, driving contra rotating props with 3.5 m diameter via a long shaft

Dimensions:
span 15.2 m, sweep angle 24 ° in 0.25 chord (?), wing area 42 sqm, aspect ration 5.5
length 15.350
height 4.7 m

Weights: NO DATA AVAILABLE
We can proceed on the assumption, that take-off weight would have been around 10 to 10.5 t

Performance : NO PERFORMANCE CALCULATIONS AVAILABLE
We can proceed on the assumption, that performance would have been somewhat better, than for the
high performance fighter with As 413 from 1. October 1944, with the exception of the endurance, which
would have been around 3 hours, using maximum cruising power at 10 km height.

Military equipment:
Armament:
1 MK 103 with 30 mm calibre in the nose
and 2 MK 103 with 30 mm calibre besides the cockpit.
"
This part seems to come directly from a contemporary document, please note the lack of performance and
weight data.
The next part certainly is a interpretation by the author and to my opinion a very good one:

"On condition that the time for development of the structure would have been normal and propulsion system
readily available, the German airforce could have get this aircraft maybe in 1948. Considering the quick development
of jet fighters, which in addition generally had a lighter and easier structure, even in 1944 the reason for such a
design must have been doubtful. For an interim timeframe, the improved Ta 152 could have taken the tasks for an
piston engine driven high performance fighter.
Nevertheless, for the reader, who is interested in aviation, these designs still have some kind of fascination, as they
marked the last stage of these developments, which stamped that era."

 

[blackkite]

Excellent!
I thank you very much for your quick and gentle response.
4000hp!!

Please enjoy another drawing.

 

[Basil]

Blackkite,

that is the book I had mentioned above. I own the German edition; my link should be the English version of the book.

 

[blackkite]

Many thanks Basil! I'm trying to get the book.
I already have following books, but I don't have fighters. I am asking myself why? :-[

 

[Jemiba]

A sad sight, nevertheless a good photo !
You may be right, perhaps I was to fixed on a large fan, driven directly by the engine, as in the
Shinden or maybe Fw 190, an installation as in your car could probably be used in an aircraft, too,
but would have to be bigger, heavier and just dead weight during flight.
Perhaps we should just go to the USAF Museum Dayton and have a look ...

 

[blackkite]

Hi! Never mind.
To understand Mixmaster is very hard for me. I can't find cooling air outlet still now.
Perhaps these books will help us.
Sorry off topic as usual. ;D

 

[BAROBA]

Those two 'books' are printed-out wikipedia-articles...
Not worth the money...

 

[blackkite]

Oh thanks so much! I already ordered the first one.(cheap one) ;D

 

[robunos]

The Mixmasters' cooling radiators were in the wings. From 'Douglas Mixmasters', 'Aeroplane Monthly', September 1975.pp. 436-31.

"The chosen engines were Allison V-1710-125 vee twelves,each rated at 1725 hp, chosen because liquid-cooled engines with wing radiators seemed easier to install in the fuselage...In the inner wing leading edges were shallow inlets leading to triple ducts, the innermost serving the oval oil coolers and the outer pair the large engine coolant radiators, all exhausting at a suitable point on the upper surface at about 65 per cent chord."

See also the images in the Mixmaster topic;



http://www.secretprojects.co.uk/forum/index.php/topic,8699.msg163123.html#msg163123


cheers,
Robin

 

[blackkite]

Thanks Robin!
How do you think about the existence of XB-42's radiator cooling fan?

 

[robunos]

Blackkite, I think you're right about the cooling air exit, and I've just found this, from Putnam's 'McDonnell Douglas' Volume 1, page 363;

"The laminar-flow wing with double slotted flaps housed the fuel tanks and the oil and coolant radiators which were fitted with ground cooling fans."

Later, on page 363-4, it says this; "...limited efficiency of the cooling ducts. Solutions...were found relatively quickly..."

I think these fans would have to have been driven electrically, and not directly off the engines.

cheers,
Robin.

 

[Jemiba]

Then it has been the same solution, as in our car, probably with the same nerving characteristic,
to produce a high whimpering sound, even when the engine is already shut down !
Thanks Robin !
And excuse me blackkite, I was wrong, you was right !