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Discussion in 'Warbirds / Warbird Replicas' started by Saville, Oct 5, 2019.
Is that right? I didn't know.....
Ok...you really want go down this way.... !?
The first Messerschmitt 262 prototype made its first flight with straight wings, a piston engine and propeller in the nose, because jet engines were not ready. It also had a tail wheel.
When they installed jet engines, they had to sweep wings to balance the airplane, especially after the piston engine was removed from the nose.
Mounting jet engines well out on the wings just followed tradition, but they soon learned that mounting them closer to the fuselage vastly reduced yaw problems after one engine quit.
Tailwheel undercarriage proved problematic with jet engines. With the thrust line below the wings, they could not dip the nose to flatten angle of attack to accelerate during take-off. Test pilots resorted to tapping brakes to bring the nose level.
Messerschmitt engineers solved the problem by installing tricycle landing gear in later prototypes and all production Me 262s.
99 percent of later jets have tricycle landing gear.
Actually, might need a twin engine jet rating or authorization. Good luck with that.
Light sport? A 262 is one of my 103 daydreams...
Have a look at this:
Wings were swept in the earliest prop version too..naturally.
We report, you decide:
Does it look like a Wright Flyer to you ?
Don't looked swept to me.
Oh, Yes! Now I see it!
They look exactly alike, except for the differences!
And this? Me-262 vs DC-10 vs Lockheed 1011 TriStar, wing swept angle differs, but main wing plan form is very, very similar. 'There is no worse blind than those who refuse seeing' (Spanish proverb) Or you claim, same as Soviets, when accused of plagium of US Aircraft designs, that: 'Aerodynamics is same for all, thus aircraft with same purpose are similar'? Gesund +
Might find these articles/sites interesting... the ME262 is a 'secret favorite' of mine... really needed reliable jet engines... J85 [CJ610] was the perfect 'replacement' for real and replica's alike.
Guys, if you keep posting pics of airliners, the thread will move on to pedals.
Yes let's keep it Me-262 bound.
I have loaded a three view of the two place version into a CAD program. A 50% version is possible if the pilot is in a reclined seat and the canopy sill line is dropped at least 6 inches. If you don't drop the sill the canopy opening isn't wide enough to get into the cockpit. Perhaps a better scale would be closer to 60%. This makes for a good sized airplane with a 24 ft. wing span. The 50% would be doable and gives about a 20 ft span. A 50% true scale version would have about 65 ft2 of wing area so the weight would have to be minimized to keep the wing loading down. I did a restaurant placemate estimate and it's easy to see the gross approaching 1000 lbs for a WL over 15 lb/ft2.
I have looked at large EDFs (electric ducted fans) and the largest on the marked is the 250 mm Vasy fan (http://www.vasyfan.com/) that develops 125 lbs of thrust on 35 kw (46 HP) for a total of 250 lbs.. Compare this to the Subsonex with about 260 lbs of thrust. It would be a challenge to keep the weight down. Vasy also makes a 395 mm, but doesn't have any specs for it on their web site.
One could drive each 250 mm fan with something like a Hirth F-23 (http://www.recpower.com/hirth.htm) if you were comfortable with the two-stroke reliability. The 395 mm version would take something larger like a Hirth 3703 (100 HP). There's also a like of rotarys on the market with a single rotor 40 HP and two rotor 100+ HP that might fit better. See: https://www.wankelsupertec.de/pdfs/datasheets/KKM350_Datasheet.pdf
There are certainly other high output engines that would fit into the nacelles.
Then there's the hydrid version, maybe with the engine/generator in the fuselage. That would be even a bigger development program, but would have several advantageous.
There will be a lot of duct drag if you put a cold fan in a long scaled turbojet nacelle.
That's true, but also true if you put a small modern turbojet in the nacelle designed for the original Jumo. It doesn't matter so much with the turbojet because its power density is so much higher than a cold jet.
The cold jet has appeal because of the stupendous cost of jet engines and the FAA requirements to fly planes powered by them. At this point it's all a mental exercise anyway.
Taking that mental excercise just one more step - has the IC/electric hybrid discussed here so casually as a "solution" gained acceptance in the light aircraft market lately?
And do you want to develop this radical propulsion system at the same time as a new airframe?
Probably not. It does introduce a whole nother development program to the project. I mentioned it only because if it were possible it does solve the problem of powering a cold fan in a nacelle.
We are currently flying an experimental aircraft with four 120 mm battery powered EDFs in addition to the normal IC engine. We're using only batteries at this time, but have been looking at the hybrid solution.
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