Caproni-Campini

[Red Admiral]

What are people's opinions/information on the second jet aircraft to fly?

There is a lot of contradictory information that I'm trying to make sense of.

[Kutscha]

It was not a true jet since it used a 900 hp Isotta-Fraschini radial engine to drive the first stage compressor.

diagram, http://www.airbornegrafix.com/HistoricAircraft/ThingsWings/CC2.htm

[Grifo]

I think it depends on what we intend with the word "jet".

BTW, CC.2 was often described in italian with the term "motoreattore", that can be translated in english more or less as "jet assisted by an engine".

[Tophe]

On the what-if modeller forum ( http://www.whatifmodelers.com/forum//index.php?showtopic=11139 ), Archibald said the word (in French) is thermojet for the old Coanda (then Campini then MiG) "piston + afterburner", while the Whittle-Heinkel ones were turbojets. Does that sound good too in English? (as I am French too, I do not know...)

[Groggy]

quote:Originally posted by Kutscha

It was not a true jet since it used a 900 hp Isotta-Fraschini radial engine to drive the first stage compressor.

diagram, http://www.airbornegrafix.com/HistoricAircraft/ThingsWings/CC2.htm


Hi Folks,
The flight of the Caproni Campini CC2 (N-1) was well publicised at the time. Details of the “engine” optimistically shown in from memory a “supersonic aircraft?” were shown in Flight with at least one feature appearing in the Junkers Jumo engine and contributed directly to the success of the German engine.
The schematic view of the Caproni version of a hybrid "jet" engine does not show the feature
Has anyone any details of the 2WW Italian supersonic wind tunnels please?

Strangely an American NACA report circa 1945 advocated a similar design as the basis for future research.

[Red Admiral]

So far as I can tell the story is thus;

1934 and the RA orders 2 aircraft and 1 ground test airframe for 31/12/36.

Aircraft not ready for 1936 because of lack of money and lack of the Isotta-Fraschini L121 engine (probably due to lack of money). Construction was progressing at this point however. Airframe finished sometime before 1940. CC.1 finished and flown in 1940, CC.2 with some undisclosed improvements flown in 1941.

Most figures give a top speed of 325km/h-375km/h but its doubtful whether the afterburner was ever used whilst in flight and the flight tests explicitly state that speed/altitude tests weren't conducted. However, Storia Militaire (09/03) states that Mario De Bernardi with CC1"easily touched 500 km/h at 5800 mts during trials in 1942".

Its not particularly surprising that CC.1 wasn't that fast, 650-750kgf but with an airframe weighing 4400kg. E.28/39 having 800kgf and weighing 1770kg. Also the CC.1 had a massive wing giving extremely low wing loading and more drag. The CC.1 was expected to fly fast at high altitude so it was given a large pressurised cabin, the weight of which meant that it couldn't fly high and fast.

Now the actual engine itself seems to have been a ramjet with a mechanical compressor. Ing. Campini stated that at higher speeds the compressor was to turned off and the simple and more efficient ramjet to be used instead. The x-section shown above is wrong. There is the compressor first of all, 3-rotor (some sources say 2 rotor-1 stator) with variable pitch blades driven from the L121 engine (960hp max). The L121 was aircooled and the heat from the engine created the thrust which was passed out through a venturi section nozzle. At the rear of the fuselage was a series of afterburners and the never-ending pelton bullet for thrust control. Thermodynamically speaking, the principle is exactly the same as for a turbojet without the rear turbine.

I don't have much information on the supersonic wind tunnels at Guidonia to hand, but there was some info in the RAeS monthly publication in 2002 i believe detailing the 1936 Volta conference and other things.

[GregP]

To me, this will never be a "jet."

That does not detract from the innovative aircraft and powerplant in any way, but it simply is not a jet. It is a hybrid piston-turbine concoction that flew and had potential that was never realized due to the war and other political considerations, most of which conspitred to remove all the money from the project. Without funds, there is little "development."

Today, there are numerous turbines, so there is no interest. 50+ years of turbines have shown that, while expensive, the reliability of a turbine engine is many times the reliability of a piston engine. Hence, there is no interest in a piston-turbine hybrid due to the expected drop in reliability.

Still, an interesting and unique aircraft and engine setup.

[Wuzak]

quote:Originally posted by GregP

To me, this will never be a "jet."

That does not detract from the innovative aircraft and powerplant in any way, but it simply is not a jet. It is a hybrid piston-turbine concoction that flew and had potential that was never realized due to the war and other political considerations, most of which conspitred to remove all the money from the project. Without funds, there is little "development."


It is sort of a ducted fan device with afterburner!

Could have been useful had turbojet developments been delayed even more than they were.

[montanamotor]

Well, folks,

this kind of "hybrid-powerplant" could still be of use even today.

Fact is that, jet-engines burn one-hell-of-a-lot fuel per pound of thrust - especially while in low power settings at low levels. In this case, a jet is BY FAR inferior, concerning the fuel-consumption per pound of thrust, than a well-developed piston-diesel would ever be.

So, a plane which was specifically used or even specially developed for a mission-envelope as to fly low and slow at long ranges, or for long times with short, intermittant bursts of high thrust required - i.e. marine-patrol-aircraft, for example, or ground-attackers for interdiction strike-missions - might greatly profit from a combination of a fuel-efficient twostroke-diesel-driven ducted fan, coupled with a strong jet-afterburner.

Imagine a Napier Nomad driving a ducted fan at the front, and a compressor at it's rear, which would blow cold air through rear-mounted combustion chambers at cruise. During take-off, in attacks or for evasive action, the cold airstream through the combustion chamber would get fuel injected and ignited, to give a strong afterburner to deliver short bursts of hight thrust, and you'll know, what I mean.

Try to imagine an A-10 Warthog with two Nomad-driven ducted fans with afterburners at it's waist, and you'll know, what I mean.

Of course, piston-engines in aircraft are not "stylish" and "fashion" any more in military aircraft. So it's very unlikely that such a hybrid would ever see the skies.

But - it's not MY fault the military aircraft developers don't listen to my wisdom... - so don't put the blame on me! :)

Cheers!

Montanamotor

[Wuzak]

I can't help but think that a liquid cooled engine would be better for this purpose.

Place the engine remotely, outside of the duct area. Place a radiator in the duct after the fans to add energy to the airflow. Use manifolds to direct the exhaust into the airflow too for a little added thrust.

[montanamotor]

Wuzak,

yeah, why not? There are several ways to home in on this topic. For example, I remember the piston-jet-hybrid being suggested in a conceptual drawing from BMW to the german RLM (Reichsluftfahrtministerium) in 1942, using a BMW 801 for driving the ducted fan in front and compressors at the rear. It was suggested as powerplant for heavy bombers - mainly, to overcome the initially poor reliability of jet engines, which made them unsuitable for use in long-range-bombers at the beginning.

The drawing I have in one of my books. Darn, I have stored most of my books 'n stuff in a storage house as I have been forced to move almost every year for the last four consecutive years, always moving to new employments. Being a journalist can be a curse, ya know.

GregP knows perfectly, what I mean. Don't you, Greg?

It's getting high time to get my things back home now, I think...

Cheers!

Montanamotor

[Mark J]

Forgive me, I don't have any referance but I once read where an aircraft was built back in world war 1 that had an internal engine with a ducted fan using exhaust to assist slightly in thrust. Does anybody have any material on this as it seems the internal combustion engine assisting a jet action, is not new....

cheers

[montanamotor]

Hey, Mark J,

take that:

http://en.wikipedia.org/wiki/Coanda-1910

Approx. 400 pounds of thrust by using a 50 HP-cranker to turn a heated fan ain't too bad, is it...?

More soon.

Cheers!

Montanamotor

[Groggy]

quote:Originally posted by montanamotor

Hey, Mark J,

take that:

http://en.wikipedia.org/wiki/Coanda-1910

Approx. 400 pounds of thrust by using a 50 HP-cranker to turn a heated fan ain't too bad, is it...?

More soon.

Cheers!

Montanamotor





Hi Folks,

The Campini design for a supersonic jet aircraft goes back to 1932 with a two stage centrifugal compressor driven by a radial with an “after burner” to boost power out put. The flight of the Campini was reported in Popolo d’Italia in 1941?